question 1 Flashcards
difference between phyletic transformation and cladogenesis (types of speciation)
Cladogenesis: refers to the process in which a single species evolves into two or more distinct species, typically due to factors like geographic isolation or ecological pressures. Creates many lineages.
Phyletic transformation: the gradual change of a species over time into a different form, without branching into new species. It describes a slow, continuous evolution within a single lineage.
gradualism versus punctuated equilibrium (modes of speciation).
Gradualism: is the idea that evolution happens slowly, with small changes over a long period of time.
Punctuated equilibrium: the idea that evolution happens quickly in short bursts, followed by long periods where nothing changes much.
biocultural evolution
Biocultural evolution: refers to the idea that the evolution of species is shaped by both biological factors (like genetics and physical traits) and cultural factors (like behaviors, tools, and social practices).
example biocultural evolution
In hominins is early humans, like Homo habilis, using stone tools. Their biology allowed them to make tools, and their culture helped them learn and pass on how to use them. Over time, using tools influenced both their bodies (like hand shape) and how they lived.
mutation
Is a change in the genetic material of an organism that can lead to new traits. These changes can be passed down to future generations and may play a role in the evolution of species over time. Like Darwin’s finches beaks.
What do genes code for?
Genes code for the traits and characteristics of an organism, like its physical features (eye color, height) and how the body functions (like metabolism or blood type). They are the instructions for how an organism grows and develops.
natural selection
is the process where organisms with traits that help them survive and reproduce are more likely to pass those traits on to the next generation. Over time, this leads to those traits becoming more common in a population. It’s a key mechanism of evolution.
founder effect
The founder effect happens when a small group of individuals starts a new population. Because the group is small, the new population may have less genetic variety and different traits than the original one.
genetic drift
Genetic drift is when traits in a population change by chance over time, not because they are better for survival. It’s more noticeable in small groups.
Gene flow
Gene flow is the transfer of genetic material between different populations of the same species. It happens when individuals from one population move to another and mix their genes, increasing genetic diversity.
Concerning apes (including humans),the difference between the phenetic (anatomical) classification and the cladistic (genetic) revision based on evolutionary relationships discussed in lecture (a diagram of the contrasting breakdowns can be found in the Resources section, titled: PheneticVsCladisticClassification.docx). What kind of information is the new cladistic/genetic classification based o n (besides, of course, DNA)?
The information that the new cladistic/genetic classification is based on besides, of course, DNA would be protein sequences and immunological responses.
Examples of Lesser Apes and the Great Apes
lesser apes: Gibbons and Siamangs
Great apes: Gorillas, Orangutans, chimpanzees, bonobo, humans
What general behavioral characteristics are associated with each species (diet, type of social group, etc.), physical characteristics, their geographic distribution in the wild, and any famous primatologists that you now know studied at least two of these species (hint). For this information, draw on your lecture notes, the videos “Primetime Primates” and the other film on primates that we watched in class, and the course textbook.
Lesser apes: herbivores, mainly fruit and leaves. Monogamous social group, smaller in size, smaller brain size, tropical forests in Southeast Asia, known for loud calls between each other, brachiation locomotion, smaller brain but still demonstrates cognitive abilities.
Great apes: Dian Fossey for gorillas and Jane Goodall for chimps, omnivores- fruits, leaves, and insects sometimes meat, larger social groups- complex and hierarchical, vocalizations and gestural communication, some have been taught sign language, more advanced tool users, much larger body size and larger brain size relative to their body size, found in central west Africa and southeast Asia.
Moreover, you should be able to name the superfamily, family, genus, and species (based on the new Cladistic Classification) for the gorilla, chimpanzee, and bonobo.
Superfamily for all: Hominoidea
Family for all: Hominidae
Gorilla genus and species: genus-gorilla and species- Gorilla gorilla
Chimpanzee genus and species: genus- Pan species- Pan Troglodytes
Bonobo genus and species: genus- pan species- pan paniscus
What is the definition of a hominin (& classificatory breakdown)? Where do we find them and how do we date their remains?
Superfamily: Hominoidae
Family: Hominidae
Subfamily: Homininae
Tribe: Hominin
- Living or fossil members of our closes relatives (after split with chimps)
Found them in Great Rift Valley: East Side of Africa
Exposed beds: result of tectonic activity & erosion
Areas where hominins could survive
Be able to explain the dating procedures reviewed in lecture (relative, K/Ar, Fission Track, Cross-dating)?
Relative Dating: soil strata reflect relative age- law of superposition: principle that the bottom layer is stratified deposits is the oldest (normally)
K/Ar: Based on “Half-Life”, Time it takes for half of a radioactive isotope (K) to decay into daughter product (AR) 40K: half-life =1.3 by
Cross dating: combo of relative and absolute dating, association of remains w/ something of a known geologic age
Fission Track Dating
1) molten rock has radioactive uranium
2) after hardens, uranium violently fissions: makes fission “tracks”
3) get sample: count number of “tracks” to get amount of time since rock formed
How did bipedalism affect the skeletal system?
Bipedalism: The pelvis became wider and shorter and more bowl-like. The spine became more curved, and S-shaped which helped distribute the weight to the pelvis region. The vertebrae got larger to carry weight. longer legs for up wright walking. Bipedalism led to structural changes in the pelvis, spine, legs, and feet for efficient upright walking. It also influenced the position of the skull on the spine.
how does brain size vary in terms of general hominin evolution?
Brain size in hominins has increased dramatically over the course of evolution, from around 350 cc in early hominins to over 1,400 cc in modern humans. This expansion correlates with major changes in culture, technology, social structures, and environmental adaptations. This growth was likely driven by factors like diet, tool use, and social living which required more advanced thinking and problem-solving abilities.
Who was Sahalanthropus tchadensis and why is this species important/what did it tell us?
6 MYA: Brain size was still small so bipedal doesn’t say brain size will grow. The eyes helped determine if they walked bipedally. it is important because it helped show signs of bipedalism before Lucy. Early hominin species. Oldest known hominin species.
who was Ardipithecus and what implications does this genus have for understanding hominin emergence (i.e., environment in which hominins emerged)?
Lived about 4.4 MYA in woodland-patchy forest, human characteristics- foramen magnum under the skull and reduced canines. Ape-like characteristics- thin tooth enamel, forest diet, chimp-sized brain (350 cc) long arms opposable toe. This genus showed signs of both bipedalism and quadrupedalism.
Characterize the early hominins (members of the genera Australopithecus and Paranthropus); what traits make the gracile forms (Australopithecines) different from the “robust” ones (Paranthropines). Consult lecture, reading, and lab material – please fill out the chart that I provided!
Reflects adaptive radiation
Paranthropus: boisei, robustus, bigger teeth, larger and more robust body size, primarily eats tough nuts, tubers, and roots, bipedal but adapted to the terrain,
Australopithecus: 4.2-3.9 MYA, large Canines (males), thick molar enamel- seeds, nuts, etc., bipedal (femur tilted & can lock straight), afarensis, garhi, africanus. 1st more efficient bipeds
2nd dentition changed- reduced canines, robust forms: “megadonts”=p
limited brain development
Who is Lucy and what do we think we understand about her species? Including the early 6 MYA fossil named Toumai (Sahalanthropus tchadensis, mentioned in the film ‘Becoming Human’), what do these species imply about the sequence of changes in evolution regarding brain size and bipedalism? Which australopithecine do some researchers think is most likely to be our direct ancestor and why (there are at least two candidates)?
Lucy: 3.3 MYA Australopithicus afarensis, 40% complete, 1) short (3.3ft), 2) brain- 420 cc, 3) “modern” below waist, 4) prognathism. She represents a early hominin with bipedalism but small brain providing evidence of the early stages of bipedalism in human evolution.
Toumai: 6 MYA, Brain size was still small so bipedal doesn’t say brain size will grow. The eyes helped determine if they walked bipedally. Represents that bipedalism was shown many years before Lucy
Why are the members of the genus Paranthropus considered robust – what was their diet and why do we think so? Why do most paleoanthropologists think they became extinct?
Huge molars: thick enamel, brain size around 510 cc, Dimorphic- F: 75lbs, 4ft, M: 108 lbs., 4.5ft, prominent sagittal crest- “nutcracker man”, ultimate grinders- lived in mixed grassland & woodland: vegetarians, huge teeth and jaw muscles for crushing, grinding, chewing. Became extinct 1 MYA because they became way too specialized
What are the physical characteristics of H. habilis and H. rudolfensis (know the date when they show up)? Using the information from lectures, labs, and your textbook, be able to explain why some people think these hominins are 1) the same species, 2) different species, or 3) simply more progressive Australopiths. Use multiple lines of data in your answer [e.g., sexual dimorphic indices (SDI), cranial characteristics, etc. – don’t forget to consult Lab 9].
H. Habilis: 2.5-1.8 MYA, Brain-650 cc, Dimorphic- SDI: .87 F 70 lbs (ht. 3.3ft) M 80lbs (ht. 4ft), some prognathism, slight brow ridges
H. rudolfensis: 2-1.6 MYA, Brain- 750 cc, 5ft tall, Dimorphic- F=110lbs M=130lbs, SDI -.85, less prognathism, broader face, large molars
Two Species?
How they could be the same species would be around the same period of time, close SDI. How they could be different would be the brain sizes, body sizes, cranium structure and size.
What are the physical characteristics of Homo erectus and what do they tell us about H. erectus locomotion? When did this species show up in different parts of the Old World?
Height: 5-6 ft
Brain size: 750-1250cc (ave. 950)
Weight: 90-150lbs
“Long” cranium
Elongated occipital bun
large brow ridges
forward projecting nose
dentition- intermediate (btwn. Aust & Humans) and adapted to increasingly softer foods
Postcranial skeleton bigger, more bipedally efficient-robust leg bones- long
pelvis narrow-narrow
slender- ample surface area for sweating, good in tropics
The species was out of Africa shortly after 2 MYA- Dmanisi, Georgia, China, & Java: 1.8 MYA
Describe the Sahara Pump hypothesis and how it explains the timing of H. erectus’ geographic dispersion.
interglacial periods: forest and grasslands expansion- facilitated migration. Warmer and wetter climate easier for them to move around and reach places they couldn’t before.
glacial periods: desert expansion and good environment contracts-inhibited migration. colder and dryer climate harder to move from place to place. movement was restricted because of less suitable living places.
What other major cultural development is associated with Homo erectus that may explain why hominin dentition began to decrease in size?
The use of fire and tools like the Acheulean hand axe. These things helped them rely less on big molars to chew up raw meat it so the teeth became smaller and smaller.
Why does Alan Walker think Homo erectus could not speak like we do (know the specifics of his argument as discussed in the lecture)?
Lacked the necessary control over abdominal muscles and had differences in their thoracic vertebrae that would have made complex speech difficult. Thoracic vertebrae are half the size of humans. They may have had Broca ceria but that alone would not have helped them be able to speak like modern humans.
What are the characteristics of Homo sapiens neandertalensis? What kind of evidence do we have for the Neandertals? How do paleoanthropologists think their lifeways may have differed from ours (i.e., group size, sociality, genetic diversity and its implications, etc.)
Archaic H. sapiens of Europe- lived 200,000-40,000 (late Pleistocene). Continued to use Acheulean tools but developed “Mousterian tradition” (Levallois technique).
Neandertals: 1st discovered 1856- Neander valley. Geographic range: Europe and Middle East. Popular conception- brutish & stupid. Low skull, lack of chin, brow ridges, short & stocky, 140-180lbs, large brain ave 1500 cc, worn down incisors, adaptation to cold climate, massive nose warm up air.
At one time: 5,000 - 15,000 alive, lived in small groups (5-10 people), territories 50 to 100 sq miles- river valleys and tool stone sources usually < 6 miles distant, not as social as us- groups isolated, less innovated, inbreeding, died before age 40.
Regional Continuity Model
Modern humans evolved in different parts of the world, with local populations of humans (like Neanderthals and Homo erectus) gradually evolving into Homo sapiens in their respective regions.
How modern sapiens evolved.
AMHS evolved same time in major regions of the Old World ( African Europe, & Asia)
Some gene flow between populations
Mix with AMHs (coming out of Africa) and AMHS derived from European Neandertals, and Asian H. erectus.
Evidence: European & Asian populations show an affinity for early hominin ancestors- Europeans, feature more robust (Neandertals), Asian, more gracile (erectus & Denisovans.
replacement model
Modern humans evolved in Africa and then spread to other parts of the world, replacing other human species like Neanderthals and Homo erectus.
Homo erectus populations in Africa gave rise to AMHS in Africa (via H. heidelbergensis). Then migrated to Europe & Asia, replacing erectus and Neandertals in Europe & Asia (no interbreeding)
Evidence: Fossil evidence- oldest AMHS fossils in Africa consisting with African Genesis and Mitochondrial DNA- AMHS population segment w/most genetic diversity= oldest
Partial replacement model
Assimilation model: non-African pop- 1-4% Neanderthal Genome
Combines Regional continuity and replacement models.
Characterize the Upper Paleolithic. What important events happened during this period regarding culture and dispersal of AMHS?
The Upper Paleolithic period, which lasted from about 40,000 to 10,000 years ago, marks a time of significant cultural, technological, and social changes in human history. It is characterized by the emergence of anatomically modern humans (AMHS, or anatomically modern Homo sapiens) and the development of advanced tools, artwork, and social structures.
40,000-10,000 BP
Last Glacial advance
Global temp: 0॰ C (32॰F)
Today global average @ 13॰C (55॰F)
Population increase rapid
More sites (larger too)
Widely dispersed
Australia: 70,000 years (boats)
Americas: 30,000-15,000 years
*Tip of S. American - 14,800 years (Monte Verde)
What might the cave art murals have meant to Upper Paleolithic AMHS?
Cave art, such as the famous paintings in Lascaux and Altamira, likely held significant meaning for Upper Paleolithic AMHS. These murals often depicted animals, human figures, and abstract symbols, which may have had various cultural or spiritual
purposes: Spiritual and ritual significance, storytelling, or communication.
What are the four tenets of flintknapping?
- Stone topography
- Platform preparation
- Angle of force
- Amount of force
Oldawon
2.5 MYA Simple flakes and cores, associated with Homo habilis and Homo rudolfensis . Earliest known tools for the hominins. Made by striking rocks to produce sharp-edged flakes that could be used for cutting and processing food. The pebble tool had 8cm of cutting edge
Acheulean
1.5 MYA Acheulean hand axes associated with Homo erectus. Bifacial tools, meaning tools were shaped on both sides, resulting in sharper and more symmetrical edges. The hand axe has about 30 cm of cutting edge.
two di
Mousterian
300,000 to 200,000 BP Flakes and scrapers, associated with Neanderthals and early Homo sapiens. It involves shaping a Levallois stone core first and then striking it to get a large, sharp flake. This method allowed them to make several tools from one stone. The tools were used for cutting, butchering, and hunting. Mousterian flake tools provided about 90 cm of cutting edge.
“Blade” traditions
50,000 to 10,000 BP flake twice as long as wide. Made by indirect percussion technique. Technologically efficient. These blades were often used as cutting tools and can be hafted into handles to create spears and other tools. Upper paleolithic blade resulted in up to 9 m of cutting edge.
Why are stone tools so important, especially for understanding the biocultural emergence of Homo sapiens? How do the successive traditions reflect the evolutionary emergence of humans? (this topic, is indeed a possible essay question, so be prepared!)
Stone tools are important for understanding the biocultural emergence of Homo sapiens because they preserved which gives us insight into both cultural and biological evolution. The complexity of stone tools shows the evolution of cognitive abilities in early humans also social and cultural development. The development of stone tools is closely linked to physical changes in humans.
Be able to solve a simple Hardy-Weinberg equilibrium problem (always remember to start with the number representing the homozygous recessive segment of a sampled population) and a Punnett Square problem. Review the Exam 1 study guide material on this subject if you need a refresher.
Hardy Weinberg: p^2+2pq+q^2
Be familiar with the material covered in the final lecture on the concept of race. What is the original
biological concept of race and why is it absolutely inaccurate and meaningless in terms of what we now understand about our biological diversity as a species (review Lab 6 for this content as well)?
The original biological concept of race: is that there were only 3 or 4 races. Members have similar genetics Phenotypically- expressed.
Traits occur together—races: bounded geographically. It is completely inaccurate because someone could look black but their DNA could say something else like Barack Obama who is only about 50% Caucasian, 43.75% Arabic and
6.25% African.
