Anthropologisch Flashcards
1
Q
Wann entstand der moderne Mensch, der von uns anatomisch kaum zu unterscheiden ist ?
A
200.000 Jahre
2
Q
Was waren die entscheidenden Veränderungen im Lauf der letzten Millionen Jahre, die uns Menschen kennzeichnen ?
A
Aufrechter Gang (Bipedie)
Veränderungen im Kauapparat
Gehirnvergrößerung
Sprachentwicklung
3
Q
Kulturelle Evolution
A
The biological evolution of humans was accompanied by a cultural evolution, marked by three phases in prehistoric times:
Paleolithic (old stone age, ~3.3mya-10kya)
Mesolithic (middle stone age, ~20kya-5kya)
Neolithic (new stone age, ~10kya-2kya)
4
Q
Evolution of Behavior
A
Coupled with the brain’s evolutionary development is the increasingly complex behavior exhibited by hominids:
The Modern Human Mind:
• Creating artifacts and images with symbolic meanings as a means of communication
• Using knowledge of animal habits, tools, advanced planning and communication to coordinate the hunting of large game
Natural History Intelligence:
Predict the future by understanding:
• the habits of game
• the rhythms of the seasons
• the geography of the landscape
Social Intelligence:
Group bonding behavior improves survival opportunities for members. Language allowed early humans to:
• communicate ideas
• plan survival strategies
• coordinate hunting and gathering
Technical Intelligence:
Producing and using artifacts required
an understanding of abstract ideas and physical processes:
• the fracturing behavior of stone
• best angles of striking stone
• how hard to strike a stone
• trajectory of a thrown projectile
5
Q
Complex Behaviors
A
Enhancing the natural protection of rock shelter
Caring for the elderly
Toolmaking using bone and antler
Prolonged infant dependency
Toolmaking using flint
Making clothes from animal skins
6
Q
Paleolithic Tools
A
The term ”Paleolithic” refers to a time period in the development of human culture that means Old Stone Age.
It spans the emergence of the first recognizable stone tools until the development of sophisticated tool kits in the Mesolithic period (Middle Stone Age) about 20-10 kya (depending on the region, e.g. 20 kya in the Levant, 12 kya in Europe).
The earliest human tool cultures date from about 3.3 mya in East Africa (Lomekwi, Kenya) and are known mostly by their stone implements.
This does not mean that the associated hominids did not use other, biodegradable materials (such as wood or bamboo): these would not preserve well
Oldowan
First Appeared: 2.6 M yrs ago
Weber, G.W., Dept of Anthropology, University of Vienna
Acheulian
First Appeared: 1.75 M yrs ago
Mousterian
First Appeared: 200 000 yrs ago
Upper Paleolithic
First Appeared: 40 000 yrs ago
7
Q
Oldest Tools in Dispute (umstritten)
A
Cut marks from stone tools at Dikika, Ethiopia are suggested to indicate the earliest (indirect) evidence of stone tool use around 3.4 mya
(Left, McPherron S.P. et al., Nature 2010).
Tool-assisted meat-eating would accordingly start ~ 800.000 years before any other evidence found so far.
Fundamental critic is expressed:
1) “cut marks” likely random striae (trampling artefacts, left below), and
2) no actual tools were found at the site
8
Q
The oldest undisputed tools (unumstritten)
A
Lomekwi 3, West Turkana, Kenya
Dated to 3.3 Million years ago
a) In situ core and refitting surface flake
b) Unifacial core
c) Unifacial core
d) Flakes
Less developed than the first common technology known from many sites (Oldovan), but appears 700,000 years earlier than the first Oldovan (Gona, 2.6 Million years, Ethiopia). The technology cannot be associated with the genus Homo (earliest probable appearance 2.8mya)
9
Q
Use of Fire
A
At first, fire may have been ‘captured’ from natural sources, such as bush fires caused by lightning.
Later, humans developed techniques to create fire on demand. The earliest record of humans using fire:
Africa: 1.5 mya Koobi Fora (Kenya), 1.4 mya Chesowanja (Lake Baringo, Kenya), and 1.5-1.0 mya Swartkrans (South Africa), but dates and evidence are disputed, controlled use of fire or open air wildfire?
1.0 mya Wonderwork Cave (South Africa) earliest secure evidence for intentional fire. (Berna et al. 2012)
Israel: 750 kya in Gesher Benot Ya’aqov, good case for repetitive use of fire
(Alperson-Afil. et al. 2009)
China: 460 kya in Zhoukoudian, heavily disputed, likely not a fire place but water-laid accumulation of organic material
Weber, G.W., Dept of Anthropology, University of Vienna
With fire early humans could:
Remain active at night: People began using fire as a source of light to continue their activities after dark and inside caves.
Cooking with fire: Made the meat of the animals they killed more palatable and digestible. They learned to preserve meat by smoking it over a fire. Cooking also enabled them to add some formerly inedible plants to their diet, and makes starch more digestible and richer in energy.
Make better weapons and tools: Hunters formed spears from tree branches by burning the tips of the branches and then scraping the charred ends into a point.
Protect themselves from predators
Warm themselves
The unambiguous identification of paleolithic fire places is problematic. Good evidence for anthropogenic fire is the appearance of multiple indicators such as
ashes, charcoal burned bones chips of flintstone burned soil arranged hearths
The role of cooking in human evolution (Wrangham et al. 1999): Cooking led to an increase in hominid brain size, smaller teeth and jaws, and decrease in sexual dimorphism, all related to the appearance of Homo ergaster roughly 1.8 mya.
Problem: There is no good evidence for fire use in that time, the significant reduction of teeth and jaws happened later, well documented fire places appear ~ 400-300 kya
Good evidence for repeated use of a central hearth at Qesem Cave / Israel 300kya
Two superimposed use cycles Very large 4m2
In the center of the cave used by a large group
Associated with butchered animal remains and dense flint assemblages
10
Q
Paleolithic Tool use
A
It is impossible to tell with certainty what a tool recovered from an archaeological site was used for. By studying how similar tools have been used by recent 'stone age' societies, it is possible to guess at their likely function. People using only stone-based technology were still in existence well into the first half of the 20th century. Anthropologists studying these primitive cultures gathered insights into how our ancestors may have lived. Faustkeil Hackmesser Bohrer Abschlag zum Schneiden Schaber gezahntes Werkzeug Speerspitze
11
Q
Tool making methods
A
A variety of stone tool manufacturing methods have been used through- out the history of tool making. Some of these methods (particularly hard hammer and soft hammer percussion) were probably combined with other methods in the manufacturing process.
“Stone tool school” – knowledge transfer documented at Qesem Cave (Assaf et al. 2015)
Basic forms are:
Flakes: chipped from the core, less than twice as
long as it is wide
Blades: chipped from the core, twice as long as it is wide
Core: Older technologies used the core as tool (choppers, hand axes), later technologies used the flakes and blades.
Strike and pressure create typical patterns on a stone tool.
Bulb of percussion: The swollen area on a surface caused by the force of the strike, the primary feature that identifies the ventral (surface attached to the core) and proximal surface of a flake or blade artefact.
Wallner lines: wave-like continuation of the impacting impulse, located ventrally, indicating the direction of the strike
Radial lines: radial to the point of impact, ventral
Retouch: intentional flaking that modifies an artefact after detachment from the core. Involves a series of contiguous small flake scars located on the perimeter of the tool used to sharpen, thin, shape, blunt, or otherwise modify the artefact.
12
Q
Die Tool making Methoden
A
Tool making methods included:
Hard Hammer Percussion:
(Oldowan and Acheulian)
Hammer stone
Flake about to be chipped off from core
Tool partly completed as the core is ‘worked’
Levallois Method:
(Mousterian)
Tool is removed as a single large flake
Hammer stone
Core from which the large flake is struck
Soft Hammer Percussion:
(Mousterian and Upper Paleolithic)
Soft hammer made of bone
Core is being struck to remove flakes
Punch Blade Method:
(Upper Paleolithic)
Hammer stone
Antler or bone punch
Core
Anvil stone
Blades and waste flakes
Pressure Flaking:
(Solutrean industry of the Upper Paleolithic)
Antler
Small, carefully controlled flakes are chipped off from the blade
13
Q
Oldowan Tool Culture
A
Main Appearance: 2.6 mya (Gona) - 1.4 mya (Olduvai)
Associated Hominids: Au. garhi? H. habilis
H. rudolfensis H. ergaster
P. boisei?
These tools were simple river-worn pebbles that were crudely fashioned with only a few flakes being removed. Technological stasis between 2.6-1.7 mya (Stout et al. 2010 JHE).
Very difficult to attribute to species, but appear probably prior to genus Homo.
These tools typically had flakes knocked from several angles to produce a core with a cutting edge (e.g. chopper, discoid, polyhedron). Although the cores may have been used as tools, it is known that the sharp flakes were also useful in cutting.
These cutmarks on bovid bones shall document that hominids (Au. garhi) acquired meat and marrow 2.5 mya. No tools were actually found.
The site of the second earlierst tools 2.6 mya in Gona) is only 96 km to the north.
First sign of behavioural change towards lithic technology and enhanced carnivory.
Choppers:
Flakes removed from 1 side only
Proto-Biface:
Flakes removed from 2 sides
Core
Polyhedron (Core) und Discoid:
Flakes removed from all sides
14
Q
Acheulian Tool Culture
A
Main Appearance: 1.7 mya (W Turkana) - 0.2 mya (Europa)
Associated Hominids: H. ergaster/erectus H. heidelbergensis
These tools were typically ‘tear drop’ in shape and were carefully crafted with a slight bulge on each broad surface (called a ‘bi-face’).
They ranged greatly in their size, one type is called ‘hand axe’ although it is not clearly understood how they were used.
They differ markedly from the earlier pebble tools in that there appears to be a standard “design” and each tool is manufactured using a great many more blows to remove flakes.
Most successful product ever, produced for ~ 1.5 mya
Handaxe refinement through time.
Upper row – dorsal view Lower row – ventral view.
From left to right, two each are shown from Konso (Ethiopia)
KGA6-A1 (∼1.75 Ma)
KGA4-A2 (∼1.6 Ma)
KGA12-A1 (∼1.25 Ma)
KGA20 (∼0.85 Ma)
In each pair of handaxes from the respective sites, near-unifacial (left) and more extensively bifacial (right) examples are shown (except KGA20). The temporal refinement implies enhanced function through time.
Wooden artefacts:
Yew “spear”, ~ 400 kya, Clacton-on-Sea, Essex, UK. Not clear if it is a thrusting spear or another kind of tool. (Müller-Beck 2008 CH Beck)
8 throwing spears, ~ 300 kya, Schöningen, Germany. Oldest completely preserved hunting weapon. Were covered quickly by mud, thus the organic material preserved. (Thieme 1997, Nature)
15
Q
Mousterian Tool Culture
A
Main Appearance: 250 kya – 40kya (Eurasia)
Associated Hominid:
H. neanderthalensis
H. sapiens
More refined tool culture than the
typical Acheulian tool culture, less handaxes until they disappear, tools become smaller, the diversity becomes larger, sharp knifes and points
Flint became a preferred material to produce stone tools because of the
very predictable way in which it would chip when struck with another hard object (much finer workmanship was possible). The climate became colder, preparation of clothing requires sharp edges.
The Levallois tool making method involved preparing a core and striking off a large oval flake which was then retouched on one surface only.
The Levallois technique of flint-knapping
Side scraper
from Le Moustier, FranceFlint, length 9cm
Handaxe
from Le Moustier, FranceFlint, length 8.5cm
Levallois point
from Le Moustier, FranceFlint, length 6cm
The scraper made by the Levallois flake method is retouched on one surface
16
Q
Neanderthal Culture
A
There was occasional burial of their dead by Neanderthals in Europe and the Levant (e.g., Saint-Cesaire, Kebara, Amud, Dederiyeh, Shanidar, La Chapelle-aux-Saints, Le Moustier, La Ferrassie, La Grotte du Regourdou, Teshik-Tash). However, burials were less elaborate than those of modern humans. Due to insufficient excavation methods, ritual burial is disputed and some argue for natural deposition (Gargett 1999 JHE).
Other authors see evidence in the following arguments:
The grave is usually characterized by certain items found buried with the body (burnt animal bones, stone tools or “flowers”).
The position and orientation of the body are also found consis- tently the same (aligned east-west with legs curled up).
Beerdigt:
Animal bones, red ochre and horns buried with the body
Position and orientation of the body with legs pulled up as if sleeping
Flowers
Stone pillow
Stone Tools
A flute-like piece of a cave bear femur with two holes has been found at an archaic hunting camp in Slovenia (Divje Babe, dated 43 kya). The holes are likely intentional and not carnivore bites.
This would suggest advanced Neanderthal behaviour producing music. However, no hominin bones are present. Thus the association with Neanderthals or modern humans remains unclear.
Whether or not the Neanderthals possessed artistic ability also refers to personal ornaments such as perforated shells, bones, and teeth.
This 42 kya-old flute made of bird- bone (swan) is one of the earliest instruments (Highham et al. 2012) providing unambiguous evidence of music (Geißenklösterle, Germany). It is associated with Aurignacien (modern humans) culture.
17
Q
Upper Paleolithic Culture
A
Main Appearance: 45 kya – 10 kya Associated Hominids: H. sapiens
There was a rather sudden increase in the sophistication of tool making about 45 - 40 kya.
Anatomically modern humans, and probably the last of the Neanderthals, produced flint tools of much finer workmanship using a technique called punch blade, in which long, thin flakes are removed and shaped into a large number of different tool types.
European sub-cultures (traditions) include the Aurignacian, Gravettian, Solutrean, and Magdalenian.
Other material such as bone, ivory, and antler became increasingly utilized to produce very fine tools such as needles, and also personal ornaments and figurines.
Punch Blade Method:
Hammer stone
Antler or bone punch
Core
Anvil stone
Blades and waste flakes
Problem of transitional culture
Mousterian
Aurignacian
Uluzzian
Section of the Palaeolithic sequence of Grotta del Cavallo.
a. The entire stratigraphic section of Cavallo Cave, after Palma di Cesnola 1966;
b. Detail of the section showing only the late Mousterian and UP layers;
c. The section photograph illustrates the clear distinction between the very dark Uluzzian deposits from the lighter- coloured sediments of the later UP layers at the site.
Throwing sticks were a major development in the arsenal of the paleolithic hunter.
They drastically increased the ballistic range of the spear and tipped the balance in favor of the hunter.
Bone needles and harpoons appear as well.
18
Q
Hunting Big Game
A
The ability to hunt and kill large game (such as woolly mammoth and woolly rhinoceros) was a triumph of human innovation requiring:
Well developed technology to make effective weapons
Cooperative behavior to plan and coordinate a hunt An understanding of the habits and
behavior of prey animals (e.g. migration paths) A knowledge of the local landscape
to effect an ambush
An understanding of physical laws in order to use weapons (e.g. gravity on the trajectory of a thrown spear)
Bringing down a woolly mammoth required a coordinated attack and cunning.
They may have used pit falls (traps) to immobilize their quarry before they closed in for the kill.
19
Q
Paleolithic Art
A
Modern humans underwent a cultural explosion about 45 kya giving rise to prehistoric art and new kinds of tools.
The stimulus was probably a need to represent in some lasting way, ideas concerned with the unknown:
Death
Hunting success
Fertility of women
Lion man of the Hohlenstein Stadel, Germany (30 cm high) carved out of mammoth ivory about 40 kya.
Early examples of rock art are found in southern France, northern Spain (here Altamira, ~16 kya), and Australia
Painting of a warlock dressed in animal skins (15 kya) on a cave wall in the Pyrenees Mountains
Cueva de El Castillo, Spain (about 39 kya).
Horse from Vogelherd, Germany (15 cm high) made of ivory, about 32 kya.
Venus from Willendorf, Austria
(11 cm high) carved out of limestone about ~30 kya.
Chauvet cave paintings, France (about 32 kya, but recently disputed).
Venus from Lespugue, France (15 cm high) made of mammoth ivory, about 25 kya.
Cave Paintings:
One of the most famous examples of Paleolithic art is found in the caves at Lascaux in the Dordogne Valley, France.
Lascaux caves contain some of the finest art, dating back to somewhere between 17 - 15 kya.
A horse depicted with possible spears being thrown at it. Note the geometric symbol above the horse (its meaning is unknown).
An aurochs (a now extinct, giant ox) is painted over earlier images of reindeer.
20
Q
Spiritual Thinking
A
There are several hundred caves in southern France and Spain that were used by early humans.
Some of these caves contain rock paintings made by Cro-Magnon shaman
The shaman would use even the relief of the cave walls for the actual presentation of the motif (switching between the worlds).
Rouffignac cave has some 10 km of passages (map below), with the most accessible cave paintings some 750m underground ( Mitte Frankreich)
21
Q
Mesolithic Cultures
A
Mesolithic Period: Middle Stone Age First Appeared: 20-10 000 years ago
Foraging and fishing economy Characterized by:
the use of small stone tools (called microliths)
a broad-based hunting and gathering economy (including foraging for seeds from wild cereal grasses).
Sickles used to cut the grasses to gather their seeds
22
Q
Neolithic Cultures
A
Neolithic Period: New Stone Age First Appeared: 11.5 kya in the
Middle East
Plant cultivation and animal domestication
The Neolithic culture is usually associated with the beginnings of agriculture, pottery and permanent settlements in the Old World.
This shift away from a hunter- gatherer economy, to one which could provide surplus food, meant greater population densities could be achieved and allowed for the development of artisans
Neolithic Excavation Kit
Sickles used to cut the grasses to gather their seeds
Quern used to grind cereal seeds
23
Q
The Beginning of Agriculture
A
Farming began in different parts of the world at different times:
Earliest evidence is found in the so-called ‘fertile crescent’ running from Egypt to the Persian Gulf about 10 000 years ago.
By about 7 000 years ago, agriculture became established in China.
This was followed by Mesoamerica (Guatemala, Honduras and southern Mexico) about 5 000 years ago
South America
Lima beans, potatoes, squash, beans, and pumpkins
8 000 years ago
Fertile Crescent
Barley, wheat, emmer, einkorn, lentils, peas, sheep, goats, cattle10 000 years ago
North China
Rice and millet
7 000 years ago
Southeast Asia
Rice, bananas, sugar cane, tea, citrus fruits, coconuts, yam, millet, soya beans, taro, pigs > 4 000 years ago
Africa
Millets, sorghum, groundnuts, yams, dates, coffee, and melons
> 4 000 years ago
Mesoamerica
Beans, maize, peppers, squash, gourds, cotton, guinea-pigs, llamas 8 000 years ago
24
Q
Domestication of Animals
A
Numerous animals have been domesticated by humans over the last 10 000 years in many parts of the world:
Domesticated Animal
Wild Ancestor
Region of Origin
Date (Years ago)
Dog
Wolf
many places?
33 000
Goat
Bezoar goat
Iraq
10 000
Sheep
Asiatic mouflon
Iran, Iraq, Levant
11 000
Cattle
Aurochs
Southwest Asia
8 500
Pig
Boar
Anatolia
9 000
Domestic fowl
Red jungle fowl
Indus Valley
4 000
Horse
Wild horse
Southern Ukraine
6 000
Arabian camel
Wild camel
Southern Arabia
5 000
Bactrian camel
Wild camel
Iran
4 500
Llama
Guanaco
Andean plateau
6 000
Water buffalo
Indian wild buffalo
Indus Valley
4 500
Ass
Wild ass
Northeast Africa
5 500
25
Bronze Age Cultures
Copper Usage: 9 000 years ago in South-east Turkey native copper was worked by cold- hammering
6 600 years ago saw the first smelting of copper
Bronze Age: 5 000 years ago saw the first bronze created by smelting an alloy of tin and copper
Bronze was used to make implements, vessels and weapons, although stone implements continued to be used.
Pottery (beakers) made from fired clay pots became valuable storage vessels.
26
What is Evolution?
Evolution is the change of inherited characteristics of biological populations over successive generations
Microevolution describes the small-scale changes within gene pools over generations.
Macroevolution is the term used to describe large scale changes in form, as viewed in the fossil record, involving whole groups of species and genera.
The complete genome of an individual represents the individual genotype which encodes all inherited traits and is passed down from one generation to the next one.
The expression of an individual’s genes results in a particular phenotype (the sum of observable traits).
The environment is influencing this expression, and at the same time providing the test bed for the phenotype’s success.
Many individuals form a population, representing different genotypes and phenotypes.
The genes of individuals can change over time because mutations (modifications of nucleotide sequences) produce gene variants (alleles).
Genes (including those mutations) are transferred to descendants. They are recombined during sexual reproduction. Diversity is thus created in populations.
Genetic diversity and excess production is the substrate on which evolution can prosper.
Populations evolve, not individuals!
Through evolutionary mechanisms such as natural selection
neutral evolution
gene drift and gene shift bottleneck effect founder effects
the frequency of alleles will change in a population.
Those gene combinations that lead to phenotypes featuring reproductive success in a given environment will prevail.
Distinct species appear once the differences between populations are large enough so that they are reproductively isolated from each other.
Entropy in thermodynamics is a measure of disorder or randomness. A demonstrative example is an ice-cube in a glass of lukewarm whisky. It will melt and the water-whisky mix will take up a balanced temperature. The order of ice- crystals is lost as well as the fine taste of the whisky, but chaos has increased.
Entropy in information theory is a measure for the information density stored, Information is a measure for the uncertainty eliminated
Negentropy is the opposite of entropy, it is the increase of information or order
(E. Schrödinger, 1944, Austrian physicist).
Living systems are taking up negentropy and store it. For this purpose, they consume energy.
Organisms store information and evolution accmulates it in more complex organisms. Evolution thus expends energy and converts it into information.
Since the sun is the only energy source available (except nuclear power), the degree of information density we can achieve is depending on how much of this energy we can make available
Evolutionary is nothing else than change over time.
Organisms are complex systems reacting to environmental factors.
Since the environment always changes (e.g. climate, tectonics, landscape, ...), we cannot assume that living systems remain unchanged through time.
The only way to interrupt this natural process would be to stop reproduction, which means extinction.
27
Forces Operating in Evolution
Various “forces” or phenomena have a part to play in the evolutionary process:
At the molecular level:
Point mutations (single base modification)
Control of gene expression (synthesis of a functional gene product, e.g. proteins)
Rate of protein synthesis
At the chromosomal level:
Crossing over (exchange between maternal and paternal chromosome fractions during meiosis)
Block mutations (mutations affecting whole segments of a chomosome)
Polyploidy (more than two paired sets of chromosomes)
Aneuploidy (an extra or missing chromosome, e.g. 45 or 47, trisomy 21)
Independent assortment (alleles separate when gametes are formed)
At the organism level:
Environmental modification
of phenotype
Selection pressures Reproductive success 'Fitness' of the phenotype
```
At the population level:
Genetic drift (random sampling)
and population size
Natural selection altering gene
frequencies
Mate choice (intersexual selection)
Intraspecific and intrasexual competition
Immigration/emigration (gene flow)
Founder effect Population bottlenecks
```
At the species level:
Geographical barriers
Reproductive isolation
(prezygotic and postzygotic)
Selection pressures Interspecific competition
28
What is Science?
Science is the process of discovery.
Its explanations must come from observations that can be repeated and confirmed by other researchers.
Science does not invoke supernatural forces to explain natural phenomena.
Science rests on a few principles: A real universe exists independent of
perception.
This universe behaves according to certain predictable laws.
These laws are knowable through observation and testing.
Hypothese -> Experiment -> Daten -> conclusion
29
Creationists
Creationism is the belief in a single creative force in the universe.
In its extreme form, creationists believe that the earth and every living form were created in 6 days, the earth is very young (Ussher 23. Oct. 4004 BC), and all humans are descendants of Adam and Eve (Book of Genesis, Old Testament).
Creationists do not believe in evolution. Their critic focuses on dating methods, the existence of fossil forms (they should be products of Noah’s flood), and the absence of links in the fossil record. Some hardliners refuse teaching of evolution in schools.
Intelligent Design (ID) is a modern adaptation of creationism, it claims that evolutionary theory cannot fully explain the diversity of life (irreducible complexity), some supernatural force is necessary.
30
Evidence for Evolution
Evolutionary theory is supported by a wealth of observations and experiments.
Although biologists do not always agree on the mechanisms by which populations evolve, the
fact that evolution has taken place is well documented.
Evidence for evolution comes from many sources:
Paleontology: The identification, interpretation and dating of fossils gives us the most direct evidence of evolution.
Embryology and evolutionary developmental biology: The study of embryonic development in different organisms and its genetic control.
Comparative anatomy: The study of the morphology of different species.
Biogeography: The study of geographic distributions can indicate where species may have originally arisen.
Artificial selection: Selective breeding of plants and animals has shown that the phenotypic characteristics of species can change over generations as particular traits are selected in offspring.
Biochemistry: Similarities and differences in the biochemical make-up of organisms can closely parallel similarities and differences in appearance.
Molecular genetics: Sequencing of DNA and proteins indicates the degree
of relatedness between organisms.
31
Biogeographical Evidence
General principles for the dispersal and distribution of land animals are:
Closely related animals in different geographic areas probably had no barrier to dispersal in the past.
The most effective barrier to dispersal in land animals is sea (as when sea levels change).
Oceanic islands often have species that are similar to, but distinct from, those on neighboring continents. The occurrence of these species suggests that they evolved in isolation differently to their ancestors on the mainland.
The Americas play no role in hominin evolution until very recently
32
Speciation
Folie 12 vo 2
33
Extinction
Most species that have ever lived are now extinct.
Entire lineages that were once dominant have now disappeared or have dwindled in numbers as other radiations have flourished.
Often, the extinction of one group has allowed another to undergo extensive radiation into free niches
Radiations may follow extinctions but are rarely the cause of them
34
Evolution of the Human Brain
Cognitive capacity is not just a function of brain size: relative brain size appears to be more important (brain size compared to body size).
Modern humans have a brain volume
three times larger than that predicted for an average monkey or ape with our body size.
Another important factor is the organization of the brain, e.g. the development of the areas concerned with spoken language.
Several areas of the brain have undergone re-organization, while also the volume of the brain increased considerably during hominin evolution.
35
Changes in Brain Size
Selection pressures for increased brain size must have been considerable.
The normal human adult brain averages around 1330 cc, but extreme sizes are between 1000 and 2000 cc
Brain Volume for Hominin Species
* Note that Homo floresiensis is well outside the normal range for humans
Hominin Species
Years Ago (mya)
Average Brain Volume (ml)
Australopithecus afarensis Australopithecus africanus Paranthropus robustus Paranthropus boisei Homo rudolfensis
Homo habilis
Homo ergaster
Homo erectus
Homo heidelbergensis Homo neanderthalensis Homo floresiensis
Early Homo sapiens
3.5 2.5 2.0 1.5 2.0 1.8 1.8 0.5 0.2 0.05 0.095 0.08
440 450 520 515 700 575 800 1100 1250 1550 380* 1450
36
Brain Size Compared to Body Height
Brain size can be correlated to the body height of hominins.
A clear pattern emerges that indicates three distinct clusters of evolutionary development:
Australopithecines Erectines
Homo
Homo floresiensis clearly falls out side these clusters.
37
World Population Growth
The United States Census Bureau (USCB) estimated that the world population exceeded 7 billion on 12th March 2012.
While industrialized countries maintain or even reduce their population, some less developed countries still grow rapidly
38
Population Age Structure
These population pyramids show the distribution of various age groups in a population. The shape of the pyramid is indicating the reproductive capabilities and likelihood of the continuation of a population.
It shows demographic changes, for instance, the youth bulge in China around the 1960 before the one-child policy was introduced, or the male excess.
39
Human Evolution
in the Future
Over the next few thousand years, human evolution will be influenced by a number of new factors:
Natural selection pressures may select for beauty, intelligence, body symmetry, disease resistance, and tolerance to pollutants and electromagnetic radiation.
Genetic engineering may introduce new and possibly novel genes to add new traits.
Gene therapy may replace, remove, or turn off unwanted, perhaps harmful, genes.
Nanotechnology may provide a means to tinker with anatomy and physiology at the cellular level to repair or enhance function.
Prosthetic enhancements and implants (although not inherited) may extend human performance beyond its present, natural
range.
40
SETI
SETI (Search for Extraterrestrial Intelligence), is a group comprising government organizations, companies, and research institutes looking for evidence of intelligent life in the universe.
The skies are scanned for radio pulses and light beams which may have been sent by other intelligent life forms.
SETI run many other programs to help decode the mystery of life in the universe. These include:
Studies into the origin of life on Earth. The feasibility of life on Mars.
Development of new technologies for improved signal searching.
SETI is NOT involved with any research into:
• Alien abductions • UFOs
41
Primate Grades
grade: taxon united by a level of similar morphological or physiological complexity; clade: monophyletic branch of an ancestor and all its descendants
Homo sapiens is one of approximately 200 living primate species, which together constitute the order “Primates”
We, as primates, have inherited a set of anatomical and behavioral features that reflect our evolutionary history
By studying the characteristics of present-day primates,
we are able to look back
at stages in our own evolutionary development.
42
Primate Characteristics
Their anatomy is generally well adapted to an arboreal (tree-dwelling) lifestyle, there is a tendency to erect posture.
Pregnancy period is longer than in most mammals and nearly all primates give birth to single offspring.
Their ontogeny is extended allowing for sufficient time to learn social behaviors in groups, there is considerably parental investment.
They possess a high degree of encephalization which is involved in higher cognitive
processes
43
Primate Physical Features
Anatomical traits of primates:
Generalized body plan (no specialisation) providing versatility
Generalized dentition with 2I+1C+2P+3M (except New World monkeys and strepsirhines)
Basically quadruped (except humans) with great variation in locomotion
Grasping hands with opposable thumb or big toe (except some prosimians and humans)
Flattened nails instead of claws (or combinations)
Forward facing eyes with stereoscopic vision
Enclosed bony eye orbits for protection
Petrosal bulla covering the inner ear, exclusive to all primates
Weber, G.W., Dept of Anthropology, University of Vienna
```
Generalized body plan but various types of locomotion:
Vertical clinger and leaper (Indri)
Brachiator (Gibbon)
Arboreal quadruped (Uakari)
Terrestrial quadruped (Baboon)
```
Enclosed orbits and stereoscopic vision
Generalized dentition with 2I+1C+2P+3M:
The hands and feet of various primate groups:
44
Primate Tails
Features that distinguish primate tails: Tails present or absent
A prehensile tail can be used to grip things Furred or not furred
Long or short
45
Sexual Dimorphism
Gorillas exhibit marked sexual dimorphism in skull features. Female and male gorilla skulls differ from each other by:
Female skull smaller than male
Female
70-90 kg
Very small sagittal crest
Small nuchal crest
Male
150-200 kg
Large sagittal crest
Large nuchal crest
46
Primate Classification
The traditional classification of primates (illustrated in the table below) is based solely on physical characteristics.
A modern classification of primates (below) based also on genetic studies
(Tabellen Folie 6 VO 3)
47
The Evolution of Primates
The traditional view is that primates evolved during the Cenozoic after dinosaurs went extinct ~65mya. Genetic data (Chatterjee et al. 2009) provides estimates for the split of Catarrhini-Platyrrhini (43mya) and Strepsirrhini- Haplorhini (64mya).
However, the question is open how Platyrrhines got to South America? One suggested possibility is on vegetation rafts
Another hypothesis suggests that the first primates probably evolved in the Early Jurassic ~185mya before the breakup of Pangaea and the opening of the Atlantic.
Key changes in the interpretation of the fossil record deriving from this hypothesis of an early appearance are:
Primates originated while dinosaurs still roamed the earth. This challenges the widely accepted theory that primates could not establish a foothold until the end of the Cretaceous (65 Mya) when an asteroid cleared the way by hitting the earth and wiping out dinosaurs.
An earlier origin for primates makes it very likely that continental drift played an important part in initial geographical subdivisions within primates.
The new approach supports previously disputed findings from several molecular evolutionary trees calibrated with fossil dates from better-known parts of the mammalian tree (mammal-like reptiles, horses and cetaceans), where the fossil record is much more complete.
Tectonics are an important factor in primate evolution
48
Tectonics are an important factor in primate evolution
The first primates appear in the fossil record, Madagascar is already separated from Africa, there is no land bridge between Africa and Asia.
Monkeys and apes diverge, a land
bridge between Africa and Asia develops.
49
Ancestral Primate
A primate ancestor would have had the following features:
Arboreal (tree dwelling) habit
Grasping hands and feet
Long, mobile limbs
Quadrupedal locomotion
Stereoscopic vision
Upright sitting position
Nails instead of claws on most digits
Although not considered a direct ancestor, animals similar to ancient tree shrews (like the modern species on this page) are thought to have given rise to the primates. They are tiny, weighing less than 50g
Purgatorius is a shrew-sized mammal at the end of the Cretaceous period (~65mya) found in North America. It could potentially be a common ancestor to plesiadapiformes and primates.
Altiatlasius is the oldest known true primate (Morocco) dated to ~57mya. The taxonomic affiliation of this tarsier-like animal is disputed (e.g. as plesiadapiform).
Eosimias centennicus from
China lived ~45mya. The size and shape of its teeth suggest that it could be the earliest ancestor leading to monkeys and apes.
Archicebus achilles is a nearly complete and partly articulated skeleton of a primitive haplorhine from China ~55mya.
It is supposed to be the most basal member of the tarsiiform clade and could be also the most basal haplorhine.
It shows a mosaic of anthropoid features (calcaneus and metatarsals) and tarsiiform features (skull, dentition, and parts of postcranium).
A. achilles’ body mass is estimated to 20- 30g (like pygmy mouse lemur). It is an insectivorous arboreal quadruped. The size of the orbits interestingly suggest diurnal activity.
Darwinius masillae (Ida) is a virtually complete (crushed) skeleton from the Messel pit in Germany, dated to ~47mya, and assigned to adapiforms. It is a lemur-like creature and not a link leading to anthropoids. (Seiffert et al. 2009 Nature)
The juvenile female lived in a rain forest as nail bearing arboreal quadruped of about 650- 900g body weight and ~240mm body length. Her diet consisted of fruits and leaves.
50
Extant Primates
Strepsirrhines are prosimians (note: tarsier are not included here) and share common features: a reliance on olfaction, nocturnality, a lack of complex social behaviour. Their incisors protrude to form a tooth comb, many have specialized clawed toes for grooming. Most are not solitary but live in pairs or social clusters.
Haplorhines include the tarsier, the only prosimian in this group. Tarsier occupy an evolutionary status intermediate between lower and higher primates. All other haplorhines are called anthropoids.
Haplorhines are guided more by vision than olfaction, have fully closed eye orbits (lacking in strepsirrhines and most other mammals), and their lower jaw is fused at the midline (in prosimians and most mammals it remains two pieces joined by cartilage). They are mostly diurnal (except tarsier and owl monkey) and live in social groups (except orangutan). The ratio of brain to body size is larger in haplorhines than in strepsirhines, their cognitive abilities are higher.
51
Aye-Aye (Daubentoniidae)
Strepsirrhini - Lemuroidea
Fingertier (Lemuroidea):
Wet nose (rhinarium)
Thin, elongated middle finger used to extract larvae juice from inside trees
The local people of Madagascar believe that aye-ayes are a bad omen, and kill them on sight.
Taxonomy
Daubentonia madagascariensis - the only species in group
Habitat
Primary and secondary forest, rain forest, dry forest, tree plantations, spiny desert
Diet
Animal matter, seeds, fruit, nectar, insect larvae
Locomotion
Quadrupedal
Social Structure
Solitary foraging, complex social interactions
Behavior
Nocturnal and arboreal
Distribution
Wider than previously published, but occur at lower densities. Found in eastern Madagascar
52
Ring-tailed Lemur (Lemuridae)
Strepsirrhini - Lemuroidea
(Katta)
Taxonomy
Locomotion
Lemur catta - now includes only 1 monotypic species
Habitat
Scrub, spiny desert, dry and gallery forest
Diet
75% fruit, 20% leaves, 5% flowers as well as bark, sap and herbs
Quadrupedal, terrestrial running
Social Structure
Multimale-multifemale social structure with 1 alpha male
53
Ruffed Lemur (Lemuridae)
Strepsirrhini - Lemuroidea
(Kragenlemur)
Ruffed lemurs are one of the first species to disappear after selective logging - probably because they eat large fruits from large trees, which are the first to be cut.
Taxonomy
Varecia variegata - 2 distinctive subspecies
Habitat
Only found in undisturbed primary rainforest
Diet
Fruit, seeds, leaves, nectar
Locomotion
Quadrupedal and suspensory - often hang by their feet to feed
Social Structure
Variable; 1 male - 1 female, multimale-multifemale and communities
Behavior
Diurnal and arboreal
Distribution
Eastern Madagascar
54
Sportive Lemur (Lepilemuridea)
Strepsirrhini - Lemuroidea
(Wieselmaki)
Taxonomy
Lepilemur hollandorum
Habitat
primary and secondary rainforests
Diet
Locomotion
Social Structure
Behavior
Nocturnal and arboreal
Distribution
NE coast of Madagascar
55
Galago (Galagidae)
Strepsirrhini - Lorisoidea
Bushbaby (Lorisoidea)
Chimps are reported to use spears to find and also kill bushbabies in their sleeping holes.
Taxonomy
Galago moholi (Bush Baby)
Habitat
Savannah and dry forest
Diet
Mainly insects, also fruits and seeds
Locomotion
Quadrupedal climbing and jumping
Social Structure
Both social life and solitary life
Behavior
Nocturnal and arboreal, sleep in leaf nests or tree caves
Distribution
Southern Africa from Tanzania and Angola to Namibia and South Africa
56
Slender Loris (Lorisidae)
Strepsirrhini - Lorisidae
Schlankloris (Beispiel)
Their exceptionally mobile joints allow the slender loris to move swiftly when alarmed.
Taxonomy
Loris tardigradus - 6 subspecies
Habitat
Tropical rain forest, dry semideciduous forest, scrub forest, swamps, montane forest up to 1850m
Diet
Insects, young leaves, shoots, flowers, hard- rind fruits, eggs, small vertebrates
Locomotion
Quadrupedal climbing
Social Structure
Solitary foraging, sometimes in pairs
Behavior
Nocturnal and arboreal
Distribution
Southern India, Sri Lanka
57
Philippine Tarsier (Tarsiidae)
Haplorhini - Tarsiidae
Koboldmaki
Tarsiers have the highest infant-weight- to-maternal-weight ratio of any primate that gives birth to a single infant.
Taxonomy
Tarsius syrichta - 3 subspecies
Habitat
Secondary lowland and coastal forest
Diet
Animal prey (insects, lizards). In captivity will eat live shrimp and fish in a bowl of water
Locomotion
Vertical clinging and leaping
Social Structure
Groups believed to be larger than 1 male and 1 female
58
New World Monkeys (Platyrrhini)
Distribution: South and Middle America
Anatomical features:
Widely separated nostrils
pointing sideways
Three premolar teeth instead of two
Small body size (0.6 – 12kg)
Quadrupedal (moves on all four limbs)
Strictly arboreal (tree dwelling)
Some have a prehensile tail, which can be used as a fifth limb
New World monkeys have flat noses with well separated, outward facing nostrils as seen on this tamarin
59
Golden Lion Tamarin (Callitrichidae)
Haplorhini - Ceboidea
```
Goldenes Löwenäffchen
Dry nose
(no rhinarium)
The golden lion tamarin is one of the few primates to have been reintroduced to its natural habitat from captivity.
Taxonomy
Leontopithecus rosalia - (disputed) - until 1984 included all Leontopithecus species as subspecies
Habitat
Primary and secondary lowland forest from sea level to 300m
Diet
Animal matter, seeds, fruit, nectar, insect larvae
Locomotion
Quadrupedal
Social Structure
Variable; multimale, multifemale, or both
Behavior
Diurnal and arboreal
Distribution
Critically endangered species found in a small area in Brazil
```
60
Cotton-top Tamarin (Callitrichidae)
Haplorhini - Ceboidea
Lisztaffe
More than 30 000 cotton-top tamarins were exported from Colombia for pets and biomedical research on colon cancer, colitis, and Epstein-Barr virus during the 1960s-1970s
Taxonomy
Sanguinus oedipus - (disputed) - formerly included S. geoffroyi as a subspecies
Habitat
Secondary wet and dry forest and low vine tangles from sea level to 1500m
Diet
Fruit, seeds, gums, and animal matter including insects, mice and birds
Locomotion
Quadrupedal; some clinging and leaping
Social Structure
Multimale-multifemale
Behavior
Diurnal and arboreal
Distribution
Found in Columbia, Panama
61
Spider Monkey (Atelidae)
Haplorhini - Ceboidea
Klammeraffe
The spider monkey’s prehensile tail is used as a “fifth” limb when feeding.
Taxonomy
Ateles geoffroyi - 9 subspecies
Habitat
Evergreen rainforest, semideciduous forest, mangrove forest
Diet
Fruit, seeds, flowers, young leaves, buds, mature leaves, animal prey
Locomotion
Quadrupedal walking and running
Social Structure
Fission-fusion communities which divide into subgroups when resources are scarce
Behavior
Diurnal and arboreal
Distribution
Between Mexico and Panama
62
Capuchin Monkey (Cebidae)
Haplorhini - Ceboidea
Kapuzineraffe
Capuchin monkeys have been trained to perform tasks for quadriplegics.
Taxonomy
Cebus apella - 10 subspecies (disputed)
Habitat
Primary and secondary rainforest to semideciduous lowland and montane
Diet
Fruit, seeds, pith nectar, animal prey (insects and reptiles) and small mammals
Locomotion
Quadrupedal - jumping to 3-4m
Social Structure
Multimale-multifemale groups with equal numbers of males and females
Behavior
Diurnal and arboreal
Distribution
Large areas or Northern and Central South America
63
Old World Monkeys (included in Catarrhini)
```
Distribution: Africa, Asia, and Europe
Anatomical features:
Nostrils are close together and open downwards
Greater range of body size (0.8 – 32kg)
Bilophodont (double-ridged) molars
Quadrupedal locomotion (move on all four limbs)
Some are ground dwelling
Tail is not prehensile
Colobinae have cow-like stomach for digesting leafs
```
Old World monkeys have nostrils close together and facing down or forward as seen on this mandrill
64
Proboscis Monkey (Colobinae)
Haplorhini - Cercopithecoidea
Nasenaffe
Males have an elongated pendulous nose, hence the common name.
Proboscis monkeys are one of the few primates known to swim, and can cross rivers to escape danger. If startled while crossing a river, they can swim underwater for 20 meters
Taxonomy
Nasalis (Nasalis) larvatus - monotypic
Habitat
Coastal nipa palm, mangrove, lowland, riverine, and peat swamp forest below 245m
Diet
Leaves, seeds, fruit, flowers, animal prey
Locomotion
Quadrupedal; climbing and leaping
Social Structure
Variable; 1 male-multifemale groups, all- male bachelor groups
Behavior
Diurnal and arboreal
Distribution
Borneo
65
Mandrill (Cercopithecinae)
Haplorhini - Cercopithecoidea
Colorful facial markings
When sexually active, the striking facial markings on the male mandrill become even brighter than usual.
Taxonomy
Mandrillus sphinx - monotypic (disputed)
Habitat
Primary and secondary, dense rainforest, as well as gallery and coastal forests. The savanna is used rarely
Diet
Fruit and seeds, bark, leaves, stems, pith of plants, palm nuts and animal prey
Locomotion
Quadrupedal; climbing
Social Structure
Multimale-multifemale groups
Behavior
Diurnal, arboreal and terrestrial
Distribution
West Africa
66
Vervet Monkey (Cercopithecinae)
Haplorhini - Cercopithecoidea
Meerkatze
Vervet monkeys have longer pregnancies than other guenons, but the infants develop much faster after birth. It is likely that the increased dangers from savanna-dwelling predators have led to this difference.
Taxonomy
Chlorocebus aethiops - 22 subspecies, 4 of which are believed to be valid species (disputed)
Habitat
Savanna woodland, edge habitat near water from lowland swamp to the dry Sahel montane forest up to 4500m
Diet
Fruit seeds, leaves, and animal prey including invertebrates, reptiles, birds and mammals
Locomotion
Quadrupedal
Social Structure
Multimale-multifemale groups
Behavior
Diurnal, semiterrestrial, semiarboreal
Distribution
Widespread throughout sub-Saharan Africa
67
Hamadryas Baboon (Cercopithecinae)
Haplorhini - Cercopithecoidea
Mantelpavian
The ancient Egyptians considered Hamadryas Baboons to be the sacred attendants of Thoth, the scribe of the gods.
Taxonomy
Papio hamadryas hamadryas - 5 subspecies, all of which were formerly considered full species (disputed)
Habitat
Arid sundesert and savanna woodland up to 2600m
Diet
Grass seeds, roots, tubers, leaves and animal prey
Locomotion
Quadrupedal
Social Structure
Fission-fusion community
Behavior
Diurnal and terrestrial
Distribution
East Africa, Middle East
68
Hominoid Evolution
The classification of the great apes and humans is difficult.
In the light of DNA comparisons, one solution is to place orangutans in the subfamily Ponginae and to combine African apes and humans in the subfamily Homininae.
In addition, a new level of classification is created, called tribes:
Hominini for humans and pre-humans
Panini for the chimpanzees Gorillini for the gorillas.
69
A Modern Classification of Hominoids
This modern classification of the hominoids addresses the genetic similarity of gorillas, chimpanzees, and humans.
Note that under this scheme, the term ‘hominid’ (i.e. a species from the Hominidae) would refer to a ‘great ape’ or human species.
This scheme is becoming widely adopted.
70
Genetic Divergence of Hominoids
The diagram below illustrates the new way of classifying the hominoids (apes and humans) based on genetic differences:
(Folie 21 VO 3)
71
The Hominoids
Includes: apes and humans (and their ancestors) Anatomical features common to all hominoids:
No tail
Semi-erect or fully erect posture
Broad chest, pelvis, and shoulders
Relatively long arms and mobile shoulder joints Large brain
Gibbon
Chimpanse
Australopithecus afarensis
72
The Apes
Anatomical features and habits:
Brachiating (swing underneath from branch to branch)
Some mainly ground dwelling and quadrupedal (e.g., gorilla)
Arms longer than legs Flattened nose
Bony eye ridges
No tail
Orang-Utan
Gibbon
Schimpanse
Gorilla
73
White-Handed Gibbon
Haplorhini - Hominoidea
The coat color of the white- handed gibbon varies from cream to black and dark brown to red
Taxonomy
Hylobates (Hylobates) lar - 5 subspecies (disputed)
Habitat
Primary and secondary, tropical dry deciduous and moist evergreen rainforest
Diet
Fruit, leaves, insects, flowers, new stems, shoots, buds
Locomotion
Brachiation; when on large branch or ground, will hop bipedally with arms raised over head
Social Structure
Monogamous 1 male - 1 female
Behavior
Diurnal and arboreal
Distribution
Southeast Asia
74
Hominids
Characteristic features of hominids:
Most predominately quadrupedal
Most omnivorous
Typical catarrhine dentition but large teeth in gorillas and small in humans
Large and often sexually dimorphic Complex social behaviour
75
Borneo Orangutan
Haplorhini - Hominoidea
Fully matured males have large fatty flanges which form part of the power display in rivalries
Orangutans in the care of humans have been taught American sign language. One in particular has learned over 150 signs.
Taxonomy
Pongo pygmaeus - formerly 2 subspecies, but one was elevated to full species (P. abelli, disputed)
Habitat
Primary rain forest from lowland swamp to upland forest up to 1500m
Diet
Fruit, young leaves, shoots, bark, soil and animal prey including insects, eggs, baby birds and squirrels
Locomotion
Suspensory, quadrumanous climbing, quadrupedal waking with clenched fists, occasional bipedal standing
Social Structure
Solitary male whose territory overlaps the territories of several separate females that travel with their offspring
Behavior
Diurnal and arboreal
Distribution
Borneo
76
Western Lowland Gorilla
Haplorhini - Hominoidea
Adult males have enlarged sagittal crests and silvery back hair
Gorillas have feet that can grasp
Knuckles are specialized for knuckle walking
Taxonomy
Gorilla gorilla gorilla - This subspecies may be a separate species from the 2 eastern subspecies
Habitat
Dense primary and secondary forest, lowland swamp, montane forest up to 3050m
Diet
Fruit, seeds, leaves, stems and pith, animal prey including termites, caterpillars, insect larvae
Locomotion
Quadrupedal knuckle walking, climbing, suspensory, limited bipedal standing
Social Structure
1 male-multifemale groups
Behavior
Diurnal and terrestrial, arboreal climbing
Distribution
Western Africa
77
Common Chimpanzee
Haplorhini - Hominoidea
It has been hypothesized that chimpanzees in different areas have different cultural traditions (proto-culture) that are passed on from one generation to the next
Knuckles are specialized for knuckle walking
Taxonomy
Pan troglodytes - 3 subspecies (disputed). Separate from the bonobo species.
Habitat
Primary and secondary, dry woodland savanna, grassland, and tropical rainforest from lowland to montane
Diet
Fruit, leaves, flowers, seeds, animal prey including mammals, birds, ants, termites, wasps and grubs
Locomotion
Quadrupedal knuckle walking and running, suspensory, limited brachiation, occasional bipedalism
Social Structure
Multimale-multifemale, fission-fusion communities (not stable)
Behavior
Diurnal, arboreal and terrestrial
Distribution
Central and West Africa
78
Bonobo
Haplorhini - Hominoidea
Zwergschimpanse
Taxonomy
Pan panicus
Habitat
Lowland rainforest
Diet
Fruit, more leaves than chimps, flowers, seeds, animal prey including mammals, birds, ants
Locomotion
Quadrupedal knuckle walking and running, suspensory, limited brachiation, occasional bipedalism
Social Structure
Modest sexual dimorphism, large fluid communities, less aggressive interactions, genital-genital rubbing to reduce tensions, females migrate, strong female coalitions, matriarchal
Behavior
Diurnal, arboreal and terrestrial
Distribution
Central Africa
79
Hominins
Features possessed to varying degree by tribe Hominini (Homininae excl. chimps and gorillas)
Partially or habitually bipedal, with modified feet, thigh bone, pelvis, and spine Large cerebral cortex
Reduced canines
Prominent nose and chin
Reduced brow ridges
Highly sensitive skin, body hair short or reduced
Complex social behaviour
Examples:
Ardipithecus
Australopithecus
Paranthropus
Homo
80
Primate Evolution
Oldest known anthropoids about 40- 30 million years ago
Split between hominins and chimpanzees about 7-5 mya
Folie 26 VO 3
81
Miocene Hominoids
The Oligocene Aegyptopithecus and Kamoyapithecus are possible ancestors of Miocene hominoids. They appear in Africa, but there is a large time gap to Proconsuloids.
During the Early Miocene many hominoids appear in Africa. Proconsul is one plausible link between hominoids and modern apes and hominins.
During the Middle Miocene, there are many hominoids in Eurasia, but not in Africa. All Asian hominoids are closely related to orangutans.
In the Late Miocene, they are found in all three continents. Ouranopithecus could be close to the LCA (i.e. a sister taxon to Australopithecines and Homo).
82
“Dental Apes”
Monkeys and apes diverged, according to molecular data, about 25mya. First fossils appear around 23mya only in Africa .
The habitats were forests and moist woodlands.
The ape fossil record starts with “dental apes”, creatures with ape-like dentition, but monkey-like postcranial skeleton.
All apes (also the most primitive ones) in this time have a “Y5” molar pattern. They are small bodied and still lack suspensory shoulders for brachiating
83
Primate Diversity in the Miocene
From the beginning to roughly the middle of the Miocene (~23- 14mya), fossil apes were abundant in Africa while monkeys were fairly rare. After the mid-Miocene, the situation reversed.
Due to climate shifts, forests dried up, grasslands and wooded grasslands became abundant.
Since monkeys reproduce more quickly than apes, they had a better chance to colonize new niches. Also, the thorax and limbs of monkeys are better adapted to evolve quick terrestrial locomotion.
Apes sustained their link to shrinking forests. Their numbers decreased along with their habitat, even today.
The only lineage of apes that successfully managed to move into new, more open habitats was the one leading to humans.
84
Proconsul
Proconsul was first discovered in the 1920s
It shows Y5 molars, but its limbs are adapted to more monkey-like quadrupedal arboreal locomotion.
It also has a long and flexible thorax, unlike the short and stable back of supsensory apes. A tail is lacking.
Proconsuloids are either close to the origin of hominoids or a sister taxon of great apes and humans.
Includes:
Proconsul africanus, Proconsul heseloni, Proconsul nyanzae, Proconsul major
Period:
22-18 million years ago
Brain size:
150-180 cc
Weight:
20-80 kg
Distribution:
East Africa
85
Morotopithecus
Another probable candidate as ancestor of apes and hominins is the roughly 20mya Morotopithecus bishopi from Uganda.
Parts of the spine and shoulder girdle suggest that it might have possessed a short and stiff back like living apes and, unlike monkeys, suspensory shoulders
86
Mid to Late Miocene Apes
There are a number of Miocene apes ranging over the Old World but their relation to modern apes and humans is ambiguous.
Pliopithecus (16-11mya), Eurasia, small body size, gibbon-like.
Pieralopithecus (12mya), Spain, flat thorax and face, locomotion discussed as suspensory, probably close to LCA of apes and humans.
Dryopithecus (12-8mya), Africa, Eurasia, primitive Miocene ape, gorilla-like.
Ouranopithecus (10-9mya), Greece, Turkey, large body size (110kg), resembling gorilla.
Samburupithecus (9.5mya), Kenya, gorilla-like upper molars.
Oreopithecus (7-6mya), Italy, suspensory positional behaviour, most primitive known great ape.
87
Sivapithecus
Asia's sole living great ape is the orangutan, a member of the sub- family Ponginae.
This group probably evolved in Africa but spread to Eurasia after the first land
connection appeared around 17mya.
This fits fairly well with molecular data
for the split of Asian and African lineages around 14mya.
Until the early 1980s, it was generally thought that Ramapithecus was a direct ancestor to the modern human lineage.
Now reclassified as Sivapithecus (12- 8mya), it is considered a likely ancestor of the modern orangutan. Some authors believe that Sivapithecus is the male form and Ramapithecus the female form of the same species.
88
Gigantopithecus
Gigantopithecus was the largest primate that ever lived - considerably larger than the modern gorilla with an estimated body weight of 330 kg.
An early form occurred in the late Miocene but Gigantopithecus is better documented from the early and mid Pleistocene (China, Vietnam), thus co- existing with Homo erectus.
It is seen as a distant relative of Sivapithecus.
Some scholars speculate that legends of the Yeti in Asia may have their grounds in the time of Gigantopithecus
89
Human Characteristics
Teeth covered with thick enamel, reduced molars, small canines
Reduced neck muscles
Reduced lower back with S-shaped curvature
Leg bones are thickened and longer
Reduction in body hair to increase evaporative cooling
Non-opposable and forward thrusting big toe
Brain became enlarged
Short, wide pelvis for attachment of gluteal muscles for walking
Femoral head angled and strengthened
Buttress at knee-joint to allow bipedal walking
Foot has an arch with weight-bearing heel and ball
Fully opposable thumb
High forehead Head held vertically
Shortened forelimb
90
Human Evolution:
a popular view from the 1960s
The “march of progress” by Rudolph Zallinger (Time-Life Books 1965) below was in common usage since 50 years ago and was misinterpreted as a linear progression (which was not intended by the authors) from a primitive ape-like ancestor to modern humans.
It is still used in advertising as a visual metaphor for the “idea” of evolution.
91
Linear Progression vs. “Bushy Tree”
Predictions According to a Linear Progression Model
The fossil record should consistently show smooth inter- gradations from one species to the next.
The Actual Evidence Observed in the Fossil Record
Few smooth inter-gradations from one species to the next
Species tend to appear suddenly in the fossil record
Several closely related species may overlap in time and space
The species disappear as suddenly as they arrived
They are replaced by other species which might or might not be closely related to them.
92
The 4 Main Events in Hominin Evolution
A modern view of human evolution maintains that it has occurred as a series of adaptive radiations.
The 1st radiation: is that of the early bipedal apes – including the Australo- pithecines, Ardipithecus, and others.
The 2nd radiation: involved the genus Paranthropus, a group of species that exploited low-grade vegetable food sources (nuts, root tubers and seeds) resulting in (megadont) species with very large teeth.
3rd radiation: is genus Homo, with the habilines and erectines developing a larger brain, diversifying, and dispersing from Africa to other parts of the Old World.
4th radiation: involves less biological innovations, but behavioral revolution and dispersal of modern humans worldwide.
93
Human Evolution Timeline
Archaic and Modern Humans: Rapid advances in brain size; suite of new behaviors. Anatomically modern humans emerge from one of the many regional variants. Erectines: Body height of modern proportions. Increasing brain volume. Sophisticated tools are manufactured and used to kill and process small sized game.
Habilines: Brain enlargement, were the first hominins recognized to use stone tools, body remains small/slight.
Paranthropines: Early hominins specialized for eating a bulky, low-grade vegetarian diet. Developed powerful chewing muscles and a generally robust skull. Australopithecines: Possessed a gracile body form and were probably opportunistic omnivores/scavengers.
Early Hominins: Brain size similar to modern chimpanzees, body remains small/slight. Hominin status may be in question.
Folie 3 VO 4
94
Selection For Nakedness
Parasite control:
Reduced body hair improves control of ectoparasites such as fleas, ticks, and lice.
Particularly important when early hominins began to use a regular 'home base', as hatching parasite eggs could reinfect them.
Retention of head hair:
Hair on the head (and to a lesser extent the shoulders) reflects and radiates solar radiation (heat) before it reaches the skin
Thermoregulation: Shorter, finer hairs (not hair loss) in early hominins allowed greater heat loss by increasing radiation from the skin surface. Well developed sweat glands allow us to lose heat at an astounding 700 watts/m2 of skin (a capacity not approached by any other mammal)
95
Bipedalism
Of all the primates, only humans are obligate bipedal. Other primates will occasionally walk using just two legs when it suits them, such as this chimpanzee.
Humans too may occasionally exhibit ape-like locomotion - a reminiscence of our ancestry
96
Selection For Bipedalism
Carrying offspring while following the large game herds of the savannah on long seasonal migrations.
Carrying food away from a kill site or growing site to a position of safety.
Efficient Locomotion: Bipedalism provides an energy efficient method both for moving between tree patches, and later for endurance running.
Seeing over the grass
may have helped to spot predators or locate carcasses at a distance.
Holding tools and weapons
was a consequence of bipedalism, rather than its cause.
Thermoregulation:
Two major advantages of walking are:
• Smaller surface area presented to
the sun at midday (60% less).
• Greater air flow across the body when it is lifted higher off the
ground assists cooling.
Recent evidence suggests that bipedalism may have evolved while early hominins, such as Ardipithecus ramidus and Orrorin tugenensis, were still living in a forested environment .
This habitat is currently occupied by chimps.
Near-Continuous Forest -> Wooded Savannah
Early hominins foraged for food in nearly continuous forest
Food resources were readily available.
A near completely arboreal life was possible.
The cooling and drying climate caused the habitat to change in the late Miocene
Early hominins were faced with a different habitat of separated tree patches.
They were forced to leave the trees in order to seek out diminishing resources.
They also had to experiment with new food resources
97
Miocene Climate
Between the end of the Oligocene and the mid Miocene temperature increased gradually.
About 14.8 mya, a major and permanent cooling and drying step occurred, associated with increased production of cold Antarctic deep waters and major growth of the East Antarctic ice sheet. It also lead to the Messinian crisis (5.9-5.3 mya), when the Mediterranean ran dry and left a great salt lake.
Changes in climate are often correlated with the origin, extinction, or diversification of primate groups
98
From Occasional to Obligate Bipedality
The degree of bipedality in fossil hominins.
Occasional: few or weak traits related to bipedality.
Habitual: major anatomical remodeling, but retention of apelike climbing specializations.
Obligate: bipedality only
99
The Primitive Features of 'Lucy'
This is a reconstructed skeleton of ‘Lucy’ Australopithecus afarensis – one of the best known bipedal hominins.
The skeleton exhibits adaptations for walking bipedally
But it also possesses many ‘primitive’ features associated with an arboreal existence.
Jaw shape half way between V-shape of ape's and U-shape of human jaw
Chest (thorax) is funnel-shaped
Low and broad pelvis
Wrist has high mobility
Relatively short legs
Ankle joint is highly mobile
Sexual dimorphism in the canine teeth (a primitive trait)
Relatively long arms compared to legs
Finger bones are curved
Toes are long and curved
100
Changes in Locomotion
Human lower limbs have been highly modified for bipedal locomotion:
legs are longer than arms relatively lower but broader pelvis inwardly-angled femur
strong knee joint
a platform foot
By comparison, an ape’s lower limbs feature:
a long pelvis
an outwardly-angled femur grasping toes
Apes are only capable of producing a bow- legged, body-rocking bipedal waddle
101
Changes in the Femur
Gorilla Legs:
The femur is at right angles to knee
Human Legs:
The femoral head is bigger, and the femoral neck is compressed (flat and high)
Gluteus muscles of the hip lift the short, wide pelvis to prevent tilting when the opposite leg is off the ground
The femur is relatively longer and angled outwards from knee
Increased carrying angle (valgus) ensures the knee is brought well under the body (towards the median-sagittal plane) during walking
102
Changes in Knee Anatomy
In modern humans, the knee joint is adapted to bear weight through the lateral condyles, which are larger than the medial condyles.
In chimpanzees, the knee joint is adapted to bear weight through the medial condyles.
The front view of a modern human right knee joint shown in a bent position (the knee cap has been removed for clarity):
Lower end of femur (as shown above)
Lateral (outer) condyle
Femur (thigh bone)
Medial (inner) condyle
Chimpanzee:
Medial condyle higher and larger
Human:
Buttress of bone to prevent the sideways deflection of leg muscles
Lateral condyle is larger
Australopithecine:
Condyles not like either of the other two
103
Changes in Foot Anatomy
The human foot has undergone considerable modification to make it better suited to a walking mode of locomotion:
Toes became reduced in length and are no longer curved. The big toe is no longer opposable.
A transverse arch converts the foot into a spring allowing it to transmit the stresses of walking and improve walking efficiency.
Chimpanzee Foot:
Lighter shading represents points of contact with the ground
Big toe diverges (separate from other toes)
Curved toe bones
Human Foot:
Lighter shading represents points of contact with the ground
Direction of weight transmission in walking
Big toe aligned with other toes
Australopithecine Footprints:
Heel bone missing from fossil
104
Changes in Spine Anatomy
The lower spine has become S-shaped to accommodate the upright walking posture.
Compare the spine shapes of
gorilla - adapted to terrestrial quadrupedal movement
human - adapted to terrestrial bipedal locomotion
Gorilla Spine:
More straight spine
Human Spine:
Marked S-shaped spine that acts like a spring
Strong forward curvature (lordosis)
Strong backward curvature (kyphosis)
Foramen magnum is further forward so skull is balanced on spine
105
Problems Caused by Bipedalism
```
Hernias: The intestines may bulge out through our weakened abdominal wall. This is the result of our gut no longer being hung from the spine by a broad ligament as it is in quadrupeds; the problem is compounded by obesity.
Slipped disc: Lower back troubles, usually the result of degenerative changes with age, are compounded by the load being carried by only two limbs. (most frequent lower neck and lumbar region lordosis-kyphosis).
Varicose Veins: An upright posture hampers venous return, allowing blood to collect in the leg veins. Blood must overcome about 1.2 m of gravitational pressure to return to the heart. (The giraffe, e.g, has extremely tough and non-elastic skin acting as a rigid sleeve to optimize venous return).
Flat Feet: Feet may suffer strain because the body rests on just two limbs. The arches of the feet collapse resulting in flat footedness, distorted bones, hammer toes, and bunions.
Birth canal (in women): Changes in pelvic shape in response to bipedalism, together with babies born with larger skulls, cause childbirth problems
Human babies emerge face down
```
106
Changes in the Skull Base
An important diagnostic feature of bipedalism is the position of the foramen magnum on the base of the skull.
The foramen magnum is the attachment point for the skull and the spine through which the spinal cord passes to the brain.
An opening close to the rear of the skull implies a quadrupedal habit of locomotion: the head is held upright by powerful neck muscles.
An opening located more centrally on the skull, as is found in modern humans, indicates a bipedal habit of locomotion: the head balances on the spine and has less powerful neck muscles.
Chimpanzee
Opening is near the rear of the skull suggesting a quadrupedal habit
Australopithecine
Opening is located closer to the position of that found on modern human skulls
Human
Opening near the central pivoting point of the skull allowing it to balance
107
Changes in Dentition
An important diagnostic feature of ‘humanness’ are the shape and arrangement of teeth
Chimpanzee
Bottom view of skull:
Dental arch is long U-shaped
• Canines are very large
• Other teeth are large
Australopithecine
Bottom view of skull:
Dental arch is still slightly U-shaped
• Canines are markedly reduced
• Other teeth are large
• Little or no diastema (gap)
Human:
• Dental arch is parabolic
• Canines small
• All teeth are smaller
• No diastema (gap)
108
Human Evolution Timeline
In 2001, the 6-7 my old remains of a nearly complete skull with gorilla-like features was unearthed in Chad.
Nicknamed “Toumai” and assigned to a new genus, Sahelanthropus tchadensis, scientists debate whether it is human or the remains of a proto-gorilla.
Orrorin tugenensis, or ‘Millennium man’ was discovered in late 2000 at a site in Kenya.
It is claimed to be the
oldest hominin yet described and was likely biped.
Originally given the name Australopithecus ramidus, it was reclassified under a new genus, Ardipithecus.
Two subspecies have been identified: Ar. ramidus ramidus (4.4 my old)
Ar. ramidus kadabba (5.8 – 5.3 my old)
Regarded by some researchers as ‘simply an ape with some unusual characteristics’.
Discovered at Kanapoi, Kenya in 1994, A. anamensis is the earliest known species of the genus Australopithecus. It had a mixture of primitive, ape-like features and advanced, human-like features.
As many as seven species from the genus Australopithecus emerge, with a wide geographic distribution, ranging from southern Africa, through East Africa, to Chad in the north
Discovered in Kenya, a probable other genus, Kenyapithecus, appeared
A group of species from the genus Paranthropus emerge in southern and eastern Africa. Superbly adapted to exploit low grade vegetarian diet, they coexist with the emerging genus Homo.
From a probable Australopithecine ancestor emerges the first species of genus Homo.
A small-brained species with fully developed bipedal locomotion, it has a talent for shaping tools from stone. This hominin does not venture out of Africa.
What followed was an adaptive radiation of the genus Homo, leading to increased body height, brain capacity, complex social behavior, and a geographic distribution that extended well beyond Africa.
The most perplexing part of this emerging story is the discovery in 2003 of what appears to be a ‘pygmy’ species of human that lived on the Indonesian island of Flores between 100 000 - 60 000 years ago.
From a probable Australopithecine ancestor emerges the first species of genus Homo.
What followed was an adaptive radiation of the genus Homo, leading to increased body height, brain capacity, complex social behavior, and a geographic distribution that extended well beyond Africa
Timeline pictured:
Folien 13-17 VO 4
109
Sahelanthropus tchadensis
Discovered in the Djurab Desert in northern Chad, one of a few hominids discovered west of the Great Rift Valley.
Currently the oldest hominid, 6-7 mya based on biostratigraphic correlations with East Africa (problematic).
Fairly complete cranium, mandibular fragments, and isolated teeth, no post- cranium.
Face only mildly prognathic, large brow- ridges, smaller canines, no diastema, probably anteriorly placed foramen magnum.
Small cranial capacity (320-380 cc), U-shaped dental arcade, thin enamel, nuchal plane flat and 55o angled, likely quadruped Miocene ape (“Sahelpithecus”).
110
Orrorin tugenensis
Discovered in the Lukeino formation of the Tugen Hills of Kenya in late 2000, about 6 mya.
Thirteen pieces, consisting of large fragments of several thigh bones, fragments of the arm and a finger, and some teeth, at least five different individuals have been found.
The femora show a number of biped traits (head and neck shape, muscle markings) which could indeed indicate the first biped hominin.
Orrorin was larger than expected for a Miocene ape. It has small teeth with thick enamel. The canine however is large.
Other Name
“Millennium Man”
Known Date
6.0 million years ago
Physique
Likely bipedal, and a forest dweller. Little else known.
Geographical Distribution
Kenya, Eastern Africa
111
Ardipithecus ramidus
Discovered in 1994, this species was given the name Australopithecus ramidus, later it was reclassified under a new genus, Ardipithecus.
It has a short snout, an opposable toe, and may have been 1.2 m tall and weigh around 50 kg.
“Ardi” lived in a habitat comprising forests and more open woodland. It was a quadruped forest dweller but could walk upright on the ground
There are two interesting
aspects: 1) bipedality
did not evolve in open savannahs.
2) “Knuckle-Walking” is probably an apomorphy of apes and was not present in our last common ancestor.
Other Name
Two subspecies:
A. ramidus ramidus A. ramidus kadabba
Known Date
4.4 - 5.8 million years ago
Physique
Facultative bipedal forest dweller.
Geographical Distribution
Eastern Africa
112
The Australopithecines
A. afarensis
A. africanus
The term “Australopithecus” was coined by Raymond Dart (1925) for the Taung child. Australopithecines are known from a variety of habitats in East, Central, and South Africa. However, there is no evidence that they have ever left Africa.
Australopithecines are small bodied (30-50 kg) bipedal apes with funnel-shaped thorax, brains only slightly bigger than extant apes (340-550 cc), moderately prognathic faces, and a mosaic of primitive (e.g. long arms) and derived traits (e.g reduced canines, megadonty).
113
Pliocene Climate
During the early Pliocene temperatures increased, but only for a short time. Cooling then continued, ice sheets at both poles became permanent, and cyclic glaciation started ~ 3mya.
Many scholars think that these climatic fluctuations (= climatic variability) were critical to the origins of our lineage.
114
Australopithecus anamensis
First discovered in the 1990s in Kenya, later also in Ethiopia. The findings consist mainly of upper and lower jaws, isolated teeth, skull fragments, and arm and leg bones.
A. anamensis is the oldest known member of the genus Australopithecus. It existed between 4.2 and 3.9 mya. The teeth (thick enamel, megadontia) and jaws suggest a dietary shift
towards eating harder or more
abrasive foods.
Lower leg bones show the oldest unambiguous evidence of habitual bipedalism and the upper arm bone is human-like.
Other Name:
None
Known Date:
4.2 – 3.9 million years ago
Brain Size:
? cc
Height:
?m
Physique:
Partial leg bones strongly suggest bipedalism; humerus humanlike, finger bone curved
Skull Shape:
Primitive features in the skull, possibly apelike
Teeth and Jaws:
Teeth similar to those of A. afarensis (but shorter and broader), with thick tooth enamel, but larger canines, jaws U-shaped, slightly more primitive than A. afarensis but more derived than Ar. ramidus.
Geographical Distribution:
Kanapoi and Allia Bay, Kenya Asa Issie, Ethiopia
115
Australopithecus afarensis
Lucy, The First Family, and the Laetoli footprints are all assigned to A. afarensis.
Small, gracile, they existed between 3.9 and 2.9 mya.
The skull and teeth are intermediate between living apes and modern humans. The cranial capacity (350- 500 cc) is only slightly above apes.
The human-like pelvis and leg bones as well as the footprints confirm they were bipedal. However, the curved finger and toe bones, more flexible tarsal bones and other aspects of the shoulder and hip joints indicate some level of arboreality.
A. afarensis lived in open woodlands rather than in open savannas. Trees could have served as refuge or sleeping area.
Other Name
‘Lucy’, ‘First Family’
Known Date
3.9 – 2.9 million years ago
Brain Size
350 – 500 cc
Height
1.10 – 1.50 m
Physique
Light build. Some apelike features: relatively long arms, curved fingers and toes, funnel-shaped thorax, high sexual dimorphism (some even claim two species).
Dikika is a partial skeleton of a 3- year-old A. afarensis child from the Sidi Hakoma member of the Hadar region. It is dated to 3.3 mya.
Most diagnostic features for Au. afarensis are already evident at this early ontogenetic stage.
The foot and the lower limb clearly document bipedal locomotion, the gorilla-like scapula and the long and curved phalanges emphasize the importance of arboreal behavior at the same time.
Small brain (410cc)
www.modernhumanorigins.net
Little of the skull is behind the foramen magnum
A Modern Human Skull
Low forehead
A.L. 444-2
Brow ridge
Large, dish- shaped face
Wide midface Flat nose
Big, ape-like incisor
Large, thickly enameled molars
Canines larger than in humans
116
Au. deyiremeda
Au. deyiremeda was found in 2011 in 3.5 – 3.3 mya deposits in Woranso-Mille in the Afar triangle in Ethiopia.
Two mandibles, a partial maxilla, and some teeth were recovered from the sediments. The cheek bones were situated more forward than in Au. afarensis, mandibles have a very thick body, but the canine and post-canine teeth are small (except M3).
It demonstrates that at least two contemporaneus hominin species lived in the Afar region (only 35 km apart) that likely exploited different ecological niches. Possible connections to K. platyops?
117
Kenyanthropus platyops
First discovered in 2001 in Kenya, this 3.5 my old species possesses an unusual mixture of features (thus a new genus was created).
The skull is the same size and time as Au. afarensis, with a large, but in contrast to the latter, a quite flat face (a trait of later hominids).
The molars, however, are small, a trait more primitive than in other australopithecines (but cf. Au. deyiremeda).
The preservation is so bad (expanding matrix distortion plus general deformation) that it might be impossible to reveal its taxonomic affiliation.
There are speculation by Leakey and Spoor that K. platyops (3.5 mya) may be in close phylogentic relationship to Homo rudolfensis (2 mya)
118
Australopithecus africanus
Au. africanus existed between 3.7 (Little Foot) and 2.3 mya. The excavation sites are caves or cliffs with concrete-like breccia.
Similar to A. afarensis, it was also small, gracile, and bipedal, but a bit more derived. Its brain was slightly larger, the cranial vault more rounded and (almost) without crests, more flexed cranial base.
Generally considered to be specific to South Africa.
There are no older hominins in South Africa. Thought to have evolved from East African migrating population.
Other Name
Plesianthropus transvaalensis Australopithecus prometheus
Known Date
3.7 - 2.3 million years ago
Brain Size
420 – 550 cc
Height
1.1 – 1.4 m
Physique
Lightly build, lower body adapted for habitual bipedialism, approximately the same body plan as Au. afarensis, but shorter arms, probably less sexual dimorphism.
Skull Shape
Brow ridges less prominent; higher forehead and shorter face, narrower cheek bones, more rounded vault
Teeth and Jaws
Large premolars and molars, but further reduced canines, small anterior teeth (but larger than Paranthropines), shape of jaw fully parabolic as in humans.
Geographical Distribution
Southern Africa
Small brain (485 cc), slightly above apes
More rounded vault
A Modern Human Skull
Brow ridge
Low facial angle
Lower face protrudes forward into a snout (prognathism).
Not in all specimens so pronounced as here.
Very large (megadont) molars compared with modern humans (in this specimen, only roots preserved)
119
Large diversity among Australopithecines
Timeline Folie 8 VO 5
120
Australopithecus bahrelgazali
Au. bahrelghazali was discovered 1995 in Koro Toro in Chad, some 2500 km west of the East African Rift, greatly extending the known geographic range of early hominins.
The fossil find consists of a partial jawbone and seven teeth dated at about 3.5 to 3.0 million years ago.
Many scholars think that it is in fact a member of Au. afarensis.
Carbon isotope data shows a dependence on C4 resources (grasses and sedges) indicating an early dietary shift in open habitats (1.5 mya earlier than P. boisei).
The ratio of 13C/12C carbon isotopes indicates three types of different biochemical pathways in plants:
C4 plants: -16 to -10 ‰
CAM plants: -20 to -10 ‰
C3 plants: -33 to -24 ‰
95% are C3 plants, whereas grasses, sedges, maize, and sorghum are C4 plants.
121
Australopithecus garhi
Discovered 1999 in Bouri in Ethiopia, this species is known from a partial skull dated at 2.5 mya.
A. garhi is very much like Au. afarensis (could be a late survivor) but quite primitive. It has even larger teeth (canine, premolars and molars), the face is markedly prognathic and the neurocranium features a sagittal crest. Nearby postcranial remains show a mix of human and ape-like proportions (i.e. the humerus to fe- mur ratio is human-like, while upper arm to lower arm ratio is ape-like).
In the same strata, animal bones with
cutmarks and percussion marks were found, indirectly indicating early tool use.
122
Australopithecus sediba
Au. sediba are several individuals from Malapa cave in South Africa, among them two partial skeletons.
It is dated to the period just after the rise of Homo and the demise of Au. africanus ~ 2 mya. Claims are made it could be a direct ancestor of our lineage.
The cranial capacity of Au. sediba is very small, i.e. 420 cc. It has arms similar to apes, but advanced hands and short fingers. Though biped, its heel is very primitive and would lead to a strange and unique way of walking. Most likely it is a late member of Au. africanus.
123
Genus Paranthropus
P. robustus
P. boisei
P. aethiopicus
The robust australopithecines (paranthropines) are anatomically extremely specialized and represent a dead end of hominid evolution. Their masticatory apparatus is designed to produce extremely high forces at the molars, probably in response to hard object feeding (e.g., hard-shelled nuts, fibrous vegetation).
Their adaptation include enormous postcanine megadontia, increased jaw size,
enlarged chewing muscles (indicated by the sagittal crest, strong postorbital
constriction, and flaring zygomatic bones), dished faces and flexed cranial base
124
Paranthropus aethiopicus
P. aethiopicus has enough primitive traits to be a possible ancestor of P. boisei and P. robustus. However, it could be possible that the East and South African lineages are more distantly related and converged due to similar dietary adaptions.
Other Name
Paraustralopithecus aethiopicus Australopithecus aethiopicus
Known Date
2.7 - 2.5 million years ago
Brain Size
410 cc
Height
?
Physique
No postcranial remains
Skull Shape
Brain size very small, prognathic face, flat base (all primitive traits). In common with other P.: sagittal crest (largest in all hominins and more posteriorly than in other P.), concave face, flared zygomatics.
Teeth and Jaws
Very thick jaws, large molar-like premolars, very large molars (megadont). Primitive trait in contrast to the other P.: large anterior teeth.
Geographical Distribution
Ethiopia (Omo 18) Kenya (KNM-WT 17000)
125
Paranthropus robustus
Appears between 2.0 and 1.5 mya in South Africa, roughly when gracile australopithecines disappear and Homo appears.
Had a similar body to that of
Au. africanus, but a larger and more robust skull, and larger teeth.
The massive face was flat or concave, with large brow ridges and low forehead.
Massive grinding teeth in large jaws suggest that it fed on a diet of tough, coarse plant food that needed a lot of chewing. Part of their diet may, however, been termites. Animal bones were probably used as digging sticks
The growth of adult males in P. robustus continued long after puberty to produce fully developed secondary sexual characteristics (differences in size and robusticity, bimaturism, cf. gorillas and orangutans). This suggests that male reproductive strategy focused on monopolizing groups of females (Lockwood et al. 2007 Science)
```
Other Name
Australopithecus robustus Paranthropus crassidens
Known Date
2.0 - 1.5 million years ago
Brain Size
500 - 550 cc
Weight
40 - 55 kg
Physique
Bipedal, high level of sexual dimorphism.
Skull Shape
Sagittal and nuchal crests, zygomatic arch positioned forward, robust mandible with tall ramus, strong postorbital constriction, long, broad, flat face, moderate facial buttressing (anterior pillars).
Teeth and Jaws
Small incisors and canines, a thickened hard palate, extreme postcanine megadontia, premolars with molarized roots, thick molar enamel.
Geographical Distribution
Southern Africa
Small brain (530cc)
Flexed cranial base
Massive molars and “molarized” premolars, with thick enamel are well worn suggesting a tough vegetarian diet
Heavy brow ridge
Low facial angle
Massive zygomatic arch and flaring cheek bones
Small anterior teeth
Strong postorbital constriction
Prominent sagittal crest for the attachment of powerful jaw muscles
Low forehead
```
126
Paranthropus boisei
Exists between 2.3 and 1.2 mya in East Africa, roughly when gracile australopithecines disappear.
Known as “Nutcracker Man” for its very massive jaws, the largest molars of all hominins, and accommodations on the skull associated with large chewing muscle, e.g. the forward reaching crest for the M. temporalis, the postorbital constriction and the flaring zygomas to provide space for this muscle, or the forward position of the M. masseter.
Likely fed on a tough diet of low grade foods: tubers, grains, hard fruits, seeds and nuts. Isotope data also suggests grass and sedges
Other Name
Australopithecus boisei Zinjanthropus boisei
Known Date
2.3 - 1.2 million years ago
Brain Size
410 - 530 cc
Weight
35 – 55 kg
Physique
Bipedal, marked sexual dimorphism.
Skull Shape
Sagittal and nuchal crests, zygomatic arch positioned forward, robust mandible with tall ramus, strong postorbital constriction, long, broad, flat face; difference from P. robustus: no facial buttressing, shape of nasal bones and browridge.
Teeth and Jaws
Small incisors and canines, largest molars with the thickest enamel of all hominins (4x of modern size).
Geographical Distribution
Eastern Africa
127
Once We Were Not Alone
There is good fossil evidence that more than one kind of hominin lived in the same region at a time (sympatric hominins), for instance about 1.8 mya in northern Kenya.
If this happens, some key aspects of their biology will diverge as a result of competition, or the one or the other species will become rare or extinct.
Chimps and gorillas share habitats today, though with slightly different strategies (ground vs. trees, great range vs. leafs if fruits are rare).
128
Genus Homo
Homo rudolfensis
2.4 M - 1.6 M yrs ago Eastern Africa
Homo habilis
2.3 M - 1.5 M yrs ago Eastern, and possibly Southern Africa
Homo erectus
1.8 M – 50 000 yrs ago Africa, Asia, Indonesia and possibly Europe
Homo sapiens
200 000 yrs ago - Present Africa and Asia, then global
Homo ergaster
1.8 M - 0.8 M yrs ago Africa, possibly western Asia
Homo heidelbergensis
600 000 - 125 000 yrs ago Africa, Asia and Europe
Homo neanderthalensis
230 000 - 30 000 yrs ago Europe and Asia
129
Pleistocene Climate
Folie 2 VO 6
During the Pleistocene between 2.59 and 0.01 mya, glacial cycles intensified.
The genus Homo evolved mainly in this time of further cooling and drying.
The growing ice shields lowered sea levels significantly and thus created new land bridges (e.g. between the Asian mainland and Southeast Asian islands).
While temperature showed little variation from north to south in early primate evolution, latitude became a significant factor in Pleistocene. This kept hominins from moving too far north in times of harsh climate until they had sufficient cultural means to cope with these conditions.
130
A first Homo?
A finding of a partial mandible from Ledi-Geraru (Afar triangle, Ethiopia) dating to 2.80 – 2.75 mya is claimed to represent the first Homo.
Shares some primitive features with Au. afarensis (e.g. inclined symphysis) and derived features of early Homo (e.g. modestly sized teeth).
It may sample a transitional population between Australo- pithecines and later Homo which appeared at 2.4 (Omo 75-14) – 2.3 (A.L. 666-1) mya.
131
Another mysterious Homo
The Dinaledi chamber in the Rising Star Cave System, near Swartkrans, South Africa delivered more than 1500 hominin fossils that remain undated so far (possible range from >2mya - <100kya). No animal bones.
Primitive features similar to Au. (e.g. brain size 513 ccm, curved proximal & intermed. fingers, shoulder, thorax, pelvis) but also derived features like Homo (wrist, hand, ankle, foot, leg, small jaws and teeth).
Similar to Dmanisi, could be close to origin of genus Homo or late survivor (like H. floresiensis). Intentional disposal of bodies?
132
Homo habilis
Existed between 2.3 and 1.5 mya. Although similar to australopithecines in many ways, their brain size was larger. They were thought to be the first hominins producing tools (therefore the name “habilis” – the skilled one).
Because their body is small (similar to australopithecines, but larger brained), some authors put them still in the australopithecines
(Wood & Collard 1999).
H. habilis survived long, remains were found in Koobi Fora dated to 1.44mya (Spoor et al. 2007) , thus co- existing with H. ergaster for half a million years. They are thus unlikely ancestors of H. ergaster.
Bigger brain (- 650 cc)
“Bulge” in the Broca's area of the brain for speech production
Rounded cranium with no sagittal crest
Brow ridge
Smaller, narrower face than the australopithecines
Flat nose
More of the skull is behind the foramen magnum
Jaw is less massive than in the australopithecines
Projecting jaw (prognathism)
Tooth row displays a modern curve, with narrow molars
133
Homo rudolfensis
Existed between 2.4 and 1.6 mya
Only a few fossils have been found.
It can be argued that differences between large and small specimens of the early Homo grade are too great for one single species.
Instead, they can be split into two sympatric species:
Homo habilis (type OH 7) Homo rudolfensis
(type ER-1470).
However, another possibility is discussed, i.e. males and females of one species
134
Homo habilis/rudolfensis
Taxonomic Name
Homo habilis
Homo rudolfensis
Known Date
2.3 - 1.5 million years ago
2.4 - 1.6 million years ago
Brain Size
510 - 730 cc
700 - 750 cc
Height
Female ~ 1.0 m (35 kg)
~ 1.5 m
Physique
Pongid-like with arms longer than legs, curved phalanges
more derived, robust but rather human-like skeleton, Homo-like bipedalism
Skull Shape
Small face with developed nose, moderate to small brow ridges
Large and quite flat face, no brow ridge
Teeth and Jaws
Smaller, narrow molars, thinner jaw, upper premolars 2 roots
Large, narrow molars, robust jaw, upper premolars 3 roots
Geographical Distribution
Eastern, and also Southern Africa
Eastern Africa
135
Homo georgicus
Dated at about 1.8 mya, they are the earliest hominin remains found outside Africa (Dmanisi, South Georgia).
The taxonomic affiliation varies between H. georgicus, H. habilis, H. ergaster, and H. erectus.
Several individuals
were found, show- ing large variation.
With 600 cc, this is
an astonishingly small and primitive hominin migrating into Asia. Oldowan tools were also associated
Migration modifies !
Other Name
Homo habilis, Homo ergaster, Homo erectus
Known Date
Brain Size
Height
1.8 million years ago
600 - 680 cc
1.45 – 1.60 m
Physique
Skull Shape
Human-like proportions, longer legs than arms, well developed foot arch, good runners, arms more primitive (hanging arms hands forwards)
Small, short and narrow crania, marked postorbital constriction and brow ridges, flat forehead, ortho- gnathic face, forwardly placed zygomas, sagittal keeling
Teeth and Jaws
Smaller teeth than H. habilis, robust jaw in larger individuals, shallow palate
Geographical Distribution
Western Asia (Dmanisi, Georgia)
Completely preserved skull with large prognathic face and very small braincase (546 ccm).
Incredibly large morphological variation within one population, or are there two paleodemes?
Doubts that D4500/D2600 is synchronic with other mandibles D211 and D2735 (probably > 10kya difference)
136
Homo ergaster
At 1.8mya, there is a major adaptive shift in hominins, likely in response to environmental and climatic changes.
H. ergaster is the first unequivocal
member of Homo and the earliest hominin with human-like body proportions (body size increase, lengthening of the femur) indicating efficient gait. He may also be the first hominin who became a truly predator.
H. ergaster refers to what others call early African forms of Homo erectus, existing 1.8 to 0.8 mya.
It differs from the Asian H. erectus fossils in some details of the skull (e.g. the brow ridges differ in shape, and H. erectus would have a larger brain size).
May have ventured out of Africa 1.8 mya (Dmanisi, Georgia).
Other Name
African forms of Homo erectus
Known Date
1.8 - 0.8 million years ago
Brain Size
720 - 1000 cc
Height
1.50 - 1.85 m
Physique
Robust, tall, human-like proportions, long legs, shorter arms, thick long bones, narrow hip
Skull Shape
Thick skull bones, robust, low and angular from side, pentagonal from rear (largest at the base), large brow ridge, angular and occipital torus, postorbital constriction
Teeth and Jaws
Robust jaws but smaller teeth than H. habilis, shovel-shaped incisors, long and small molars
Geographical Distribution
Africa, possibly western Asia
Skeleton of Nariokotome boy
A nearly complete skeleton of a 9 year old boy was 1.6 m tall (estimated 1.85 m as an adult). Nickname: Turkana Boy.
137
Endurance Running
The capability of running long distances might have played a crucial role in evolving certain human characteristics. Endurance running could have played a role in competing with other scavengers, and later in persistence hunting (drive animals into hyperthermia and exhaustion). No other primate is able to run long distances.
Advantageous adaptations for running are: a system of springs in the leg and foot to store and release elastic energy; hypertrophied gluteus maximus and spinal extensor muscles to stabilize the trunk; elongate, and narrow waist in combination with a low, wide, decoupled shoulder girdle to counterbalance.
Some tribes in the Kalahari still hunt gemsbok, hartebeest or kudu during midday. Critic focuses on a) savanna-wooded habitats while Homo was evolving, b) tracking as a necessary skill, and c) lacking distance weapons.
138
Changes in Brain Size
Folie 9 VO 6
139
Veränderungen in Zahngröße
Folie 9 VO 6
140
Homo erectus
Homo erectus is used by many authors for the Asian forms, with dates ranging from 1.8 – 0.05 million years ago.
H. erectus succeeded in colonizing the far east, including Indonesia between 1.8-1.6 mya (the island of Java was then connected to mainland Asia). There were the oldest (Mojokerto ~1.8 mya) and the latest specimens (Ngandong 0.05 mya) discovered. Thus, H. erectus survived very long on the island refuge.
The other large sample comes from China (Zhoukoudian, Nanjing, Hexian), which are much younger (0.6 – 0.2 mya) and slightly different to the Indonesian sample.
The appearance in Europe is disputed, H. antecessor (0.8 mya, and Ceprano) might be included instead of being a separate
species.
H. erectus differs from H. ergaster by having skulls that were strongly buttressed with ridges of bone (e.g. sagittal keel, stronger brow ridge, angular torus), skull walls greatly thickened, and larger brain volumes.
Hunter-gatherers in Europe, Africa and the Near East used stone tools: first Oldowan, and a bit later Acheulean (e.g. hand axes and cleavers). These tools were standardized and persist relatively unchanged for 1.2 mya.
However, in East Asia hand axes are absent to rare (appear very late), only Oldowan-like tools were found. The border dividing these cultures is the so-called Movius line (they probably left before the invention of hand axes in Africa). The use of fire is discussed but not clearly proven (e.g. in China).
Other Name
Pithecanthropus erectus Sinanthropus pekinensis
Known Date
1.8 - 0.05 million years ago
Brain Size
800 - 1250 cc
Height
1.4 - 1.7 m
Physique
Robust, tall, human-like proportions, long legs, shorter arms, thick long bones, narrow hip
Skull Shape
Very thick skull bones, robust, low and angular from side, pentagonal from rear (largest at the base), pronounced sagittal keeling, massive brow ridge, angular and occipital torus, postorbital constriction
Teeth and Jaws
Robust jaws but smaller teeth than H. habilis, shovel-shaped incisors, long and small molars
Geographical Distribution
Africa, Asia, Indonesia, and probably Europe
Long, flattened cranium
Angular torus
Occipital lobe (bun-like swelling)
Bigger brain
Distinctive keel along the top
Sloping forehead
Massive,straight brow ridge
Flat face
Projecting jaw
No chin
Attachment for strong neck muscles to keep the head up
Teeth are smaller than H. habilis, but more massive than our own
141
Homo antecessor
Discovered in the Gran Dolina at the Spanish cave site of Atapuerca, it is the oldest confirmed European hominin
(~ 800 kya).
The young individuals (3-18a) show a mix of traits partly foreshadowing Neanderthals and partly linking to modern humans. Particularly the canine fossa is used to argue for a common ancestor of Neanderthals and moderns.
Mid-facial area seems very modern, while forehead and brow ridges appear more primitive. The teeth are also primitive.
Many scientists believe it may be a European variant of H. erectus, similar to another contemporaneous calvaria, Ceprano from Italy.
142
Homo heidelbergensis
About 600 kya transitional forms between H. erectus and anatomically modern humans appear. There is no consensus about their taxonomy, some call these archaic Homo sapiens, some others H. heidelbergensis.
They might be ancestral to later Neander- thals, and possibly to H. sapiens. The
group is morphologically very diverse (also called “garbage taxon”), but consistently differs from H. erectus, Neanderthals, and modern humans.
They were probably “local prototypes” responding to diverse regional selection pressures and frequently expanding and shrinking populations (source-sink model)
Tools industries are also diverse (Oldowan, Acheulean, Levallois), but advanced hunting spears were made in Germany (Schöningen).
The type specimens was found in Mauer/Heidelberg (609 kya) but only a mandible is available. More complete fossils in Europe came from Petralona, Steinheim, Arago 21, Swanscombe, and others. The large Atapuerca sample is sometimes included in H. heidelbergensis. However, they are closer to Neanderthals than all others.
In Africa, Bodo (600 kya) and Kabwe represent robust variants with specialized cranial pneumatizations. Ndutu and Salé are lighter built.
Asian H. heidelbergensis are known from China (Dali, Maba, Jinniushan) and India (Narmada). They don’t appear before 200 kya.
Other Name
Archaic Homo sapiens Homo steinheimensis Homo rhodesiensis
Known Date
600 000 - 125 000 years ago
Brain Size
1100 - 1400 cc
Height
1.60 – 1.75 m
Physique
Robust H. erectus-like skeleton
Skull Shape
Contra erectus: Larger brains, more parallel-sided, taller, and less angular cranial vaults, more arching than straight supraorbital torus, wider nasal apertures, less face protruding.
Contra modern sapiens: robust browridge, large face, low and thick- walled cranium, no chin.
Teeth and Jaws
Similar to H. erectus, but smaller teeth
Geographical Distribution
Africa, Asia, and Europe
Flat, oblong shape to the cranium, but higher than erectus
Occipital swelling (“bun”)
Sloping forehead
Large brain (1100 - 1400cc)
Large but arching brow ridge
Broad, upright face
Broad nasal opening
No muzzle (no prognathism)
Teeth are generally modern in form
143
Two Scenarios for the Split
A) European H. heidelbergensis as the exclusive ancestor of Neanderthals and the related Denisovans
B) European H. heidelbergensis as the last common ancestor of
modern humans, Neanderthals and the related Denisovans.
144
Proto-Neanderthals
A huge fossil sample (28 individuals) comes from the Sima de los Huesos in Atapuerca (Spain). The last dating results in 430 kya.
They are often classified as H. heidelbergensis because they show the typical suite of traits distingui- shing them from H. erectus. However, in addition they carry particular traits that are very Neanderthal-like, e.g. the double- arched brow ridge, the midfacial projection, the glenoid fossa, the mandible, and dental features
(Arsuaga et al. 2014 Science).
This suggests that they might be
directly ancestral to later Neanderthals
145
Homo neanderthalensis
The remains of hundreds of Neanderthal individuals have been found in Europe, near and middle East, and central Asia. No Neanderthal is known from Africa.
They lived fairly far north in the time between 230 - 30 kya when extreme oscillations in temperature occurred. At the end of this period, they overlap in time and space with modern humans.
They had brawny, cold-adapted bodies featuring a suite of distinct traits compared to modern humans.
Their typical tool culture is the Mousterian. Neanderthals were good hunters eating plenty of meat, but no fish/seafood.
Other Name
H. sapiens neanderthalensis
Known Date
230 000 - 30 000 years ago
Brain Size
1200 - 1750 cc
Height
1.50 - 1.70 m
Physique
More massive but shorter than modern human skeleton, barrel-shaped thorax, short forearm and tibia, adapted for cold climates. Longer sup. pubic ramus.
Skull Shape
Large, long, and low skull, double- arched brow ridge, high rounded orbits, strong midfacial projection, post. placed cheek bone, no chin, small mastoid process, occipital bun, derived inner ear
Teeth and Jaws
Shovel-shaped upper incisors, smaller teeth than erectus, lower P4 extra subcusp and asymmeric, taurodontism, retromolar space
Geographical Distribution
Europe, western and central Asia
Large brain (1600cc) Larger than modern humans but organized differently
Occipital bunning (swelling)
Skull widest in the middle (unlike modern skulls which are widest near the top, and erectines which are widest at the base)
Low, long cranium
Sloping forehead
Powerful jaw but reduced compared to H. erectus
Retromolar space
Double-arched brow ridge
Large prominent nose
Strong mid-facial projection
Swept back, lightly built cheek bones
No chin
Teeth are smaller than H. erectus, but bigger than our own
The tool making and hunting tactics of Neanderthals suggest that they used a certain level of language to communicate and to learn.
DNA results show that they had the same version of the FOXP2 gene (necessary for speech and language functions) as modern humans.
The complete hyoid bone from the Kebara Neanderthal is virtually identical with modern humans. However they lack the inverted T- shaped chin, where relevant speech muscles insert.
Likely, Neanderthals had no fully modern human language which probably appeared ~ 90 - 50 kya
The decoding of the entire Neanderthal genome finished on 19th March 2013. Every position was determined on average 50 times over.
Bones from Spain, Germany, Croatia, and Russia were used for the sampling and compared to present-day humans from different parts of the world.
Non-Africans carry 1-4% Neanderthal sequences, sub-Saharan Africans almost none.
The last gene flow into Europeans occurred 86 – 37 kya, probably when they reached Eurasia.
Neanderthals contributed more genes to east Asians than to Europeans, thus there might have been additional
interbreeding events.
146
Neanderthal Skeleton
Clavicle: long Scapula : wide
Shoulder joint: large
Hip joint: large, rotated outward
Ankle joint: large
Hand: with strong grip and wide fingertips
Pubic ramus: long
147
The “Denisovans”
In 2000 and 2008, a few hominin remains (distal manual phalanx, upper molar) appeared in the Denisova Cave in southern Siberia. They are dated
to ~ 40 kya.
The left M2 or M3 is very large, i.e. in the
range of australopithecines or H. erectus (if an M3), and has a large talon basin and no reduction of the hypocone.
A DNA analysis revealed that these fossils are a new hominin group, the Denisovans, and are closer related to Neanderthals than they are to modern humans
It also shows gene contribution of Denisovans to present-day Melanesians, but not to any other
recent humans. The third fossil, a toe
bone, is genetically a Neanderthal.
148
Homo floresiensis
Discovered in 2003 in the Liang Bua cave on the Indonesian island of Flores, nicknamed ‘the hobbit’, these hominins lived between 100 - 60 kya (Sutikna et al. 2016 Nature), thus not overlapping in time with modern humans (arriving around 50 kya), but with the last H. erectus (surviving until 50 kya on the neighboring island of Java).
The dimensions of the skull and skeleton of H. floresiensis fall well outside the extremes seen in H. sapiens.
Brain size is equal to the small australopithecines, and approaches that of modern chimpanzees (which have a brain size of 400cc).
Cranial and postcranial remains from 14 individuals include a 30- year-old female with a brain size of 426cc and standing just 1.0m tall (like the Au. afarensis “Lucy”).
May have resulted from long-term isolation, with subsequent endemic dwarfing, of an ancestral Homo erectus population (dwarf forms of large mainland mammal species are not uncommon on islands, e.g. dwarfed elephants).
Astounded scientists by showing clear signs that (despite their chimp-like brain size) these people used stone tools, fire, and hunted.
149
Homo sapiens
Being modern human is a matter of morphology, but also of behavior.
The first anatomically modern humans appear around 200 kya in East Africa. They show a transformation of the skull (globularisation), but, at first, no change in technology.
Later they underwent a sudden cultural revolution about 70 - 40 kya (depending on the region), with abundant appearance of symbolic representations that was absent from the records of Neanderthals and archaic H. sapiens.
Using a wider range of materials and techniques, their tools became markedly more sophisticated. They were skilled hunters and tool-makers but also artists, as personal decoration, music instruments
and art objects document
While Neanderthals evolved in Europe,
anatomically modern humans evolved in Africa. First fossils from Omo (195 kya), Herto (160 kya), both in Ethiopia, Ngaloba (Tanzania), and Florisbad (South Africa) look more modern, but not entirely. Around 120-70 kya, fully modern humans appear in Klasies River Mouth, Border Cave (both South Africa), and Aduma (Ethiopia). At Blombos cave (South Africa), engraved ochre and pierced marine shell beads document symbolic behavior 75 kya.
Between 110-90 kya, we find a first wave of expansion out of Africa in the Levant at Skhul and Qafzeh sites. Within a small geographical area, modern humans alternate with Neanderthals over time, most likely depending on glacial – interglacial cycles. No evidence of interbreeding was found so far.
Homo sapiens
Between 45-40 kya modern humans reach
Europe (Italy, Austria, England, Romania), bringing their new Aurignacian culture (or early forms of it) along and rapidly spread over the continent. In Central Europe Mladec and Predmosti are inhabited 35-25 kya, the famous Cro-Magnon rock shelter in France around 27 kya.
The dating of Asian sites is problematic. Liujiang could be as old as 67kya, or also 140-110kya. Daoxian is supposed to be 120-80kya. Zhoukoudian Upper Cave is 25kya, and Wadjak from Java 37kya.
Although Australia can be reached only by crossing water, quite early dates are available for a tool site (Malakunanja II) with 50kya. Hominin finds from Lake Mungo are around 31kya, other sites such as Kow Swamp or Willandra Lake are much younger (13-10kya).
Other Name
Anatomically modern humans
Homo sapiens sapiens
Known Date
195 000 – 0 years ago
Brain Size
1200 - 1700 cc
Height
1.60 - 1.85 m
Physique
Modern, more gracile skeleton, possibly adapted for warmth, barrel-shaped thorax, short pubic ramus
Skull Shape
Small or no brow ridge, rounded cranium with max. breadth high up, parallel side walls, prominent mastoid, retracted face, canine fossa, no bigger brains than Neanderthals (average smaller)
Teeth and Jaws
Reduced jaws, smaller teeth, developed chin with thickened inferior margin (inverted “T”)
Geographical Distribution
Africa and Asia (for early forms), today all continents
Large brain (1400cc)
Skull widest high up
Skhul 5
David Brill 2006
Low, rounded occipital area
Globular cranial vault
Large mastoid process
No retromolar gap
High, vertical forehead
No or only weak brow ridge, just a swelling of the glabella
Vertical face
No projecting midface
Canine fossa
Reduced jaws
Developed chin with inverted “T”
Reduced tooth size with thicker enamel
150
The Recent Out of Africa (RAO) Hypothesis
The most popular theory accounting for the origin of anatomically modern humans.
Also known as the “Replacement Hypothesis” or “Eve Hypothesis”.
Modern humans originated somewhere in Africa around 200 kya and later migrated to other regions already occupied by earlier forms of Homo.
They did not (substantially) interbreed with indigenous hominins and completely replaced them over time.
The geographical variation seen today evolved late, after the origin of anatomically modern humans.
Genetic results are in agreement in so far as Africans show a higher variability than non-Africans.
151
The Multiregional Hypothesis
Another popular theory accounting for the origin of modern humans.
Anatomically Modern Humans
Folie 23 VO 6
152
A Synthesis?
Both theories have strong arguments, but are probably not irreconcilable.
Genetic contributions from ancient populations are contra the complete replacement argument.
However, these contributions were probably minimal whereas the population expansion from a single region could have been the dominant event.
Likely, some ancient populations have been replaced without interbreeding. This does not preclude gene flow between particular other populations.
The problem of species delineation based on morphological traits is obvious in face of the genetic Neanderthal contribution to our genome.
153
Dispersal of Modern Humans
Folie 24 VO 6
Willendorf
Kent’s Cavern 43 500 ya Peștera cu Oase
The first modern humans appear in Europe and Asia 45 000 years ago
40 000 ya
Manot
55 000 ya
Misliya
170 000 ya
Herto
160 000 ya
Qafzeh & Skhul
120 000 - 92 000 ya
Haplogroup L3 appears 70-60 000ya
