Final

Question 1

• All early hominin fossils, older than 2 mya are found.. 2 main regions

Answer 1

in Africa.

Parts of East and South Africa.

Question 2

All early hominin fossils

*why Africa?

Answer 2

• Likely larger populations lived in this area than other areas.
• Geological features may help them preserve better.

Question 3

• Caves in South Africa:

Answer 3

• Taung- Taung child cranium 1925
• Sterkfontein
• Fromfraai
• Swartkrans
• Malapa- recently, found in 2008.
• These have been made UNEXCO Heritage site called Cradle of Humankind

Question 4

Dolinas

Answer 4

• Vertically oriented caves
• Formed by dissolving limestone, eroded bedrock.
• Over millions of years, these grows large and deep into large cavities with a small opening at the top.
• Stratification happens in the cave.
• Some used by hyenas.
• Some hominin groups used Dolinas for living.

Question 5

• Breccia-

Answer 5

new rock that forms over time.
* 10-40 meters deep.

Question 6

• Sterkfontein

Answer 6

20 m of breccia deposits. Date to 3.5 million years ago at the bottom and 200 000 years ago at the top.
* Over 700 hominin bones and fragments have been found here.
* Almost complete skeleton was found here, same as Taung child.
* Need to use very small tools as its wedged in there.

Australopithecus

Question 7

• Malapa

Answer 7

• Mostly complete hominin skull found date to 2 million years ago.
• .

Australopithecus sediba

Question 8

• More sites in East Africa

Answer 8

More sites in East Africa than south Africa
* Tanzania- Olduvai Gorge, Laetoli
* Kenya- West Turkana, Koobi Fora
* Ethiopia- Hadar and Kada Gona.
* Not individual sites, but large areas on the landscape where fossils are found.

Question 9

• Olduvai Gorge-

Answer 9

• 2 million years ago it was a lake, and hominins and animals lives along the shore
• Found stone tools and bones, phytoliths- plant matter from fossilized palm trees.
• Used to have lake but now dry and lots of erosion- so that means fossils are able to be found.
• Lousi and Mary Leaky started finding fossils in 1959

Question 10

• Laetoli

Answer 10

• Famous for Mary Leakey’s discovery of hominin footprints in volcanic ash from 3.5 million years ago.
• Over 70 footprints from 5 individuals, give info about walking gait at that time. Many animal footprints found as well
  Australopithecus

Question 11

• Koobi Fora

Answer 11

• Animal and hominin footprints
• 1.5 million years old.
• Genus homo fossils found here- most complete ones

Question 12

• West Turkana

Answer 12

• Old river deposits to 4 million years ago.
• Stone tools sating to 3.3 mya? Possibly- would be the oldest artifacts ever found.

Question 13

• Afar Depression- Ethiopia.

Answer 13

• Used to be thick forest and wet marshy areas

Question 14

• Hadar

Answer 14

• Rich in hominin remains, date from 4.5 to 3 million years ago
• Ongoing erosion changes the landscape and makes it so that fossils can be found even if the area was already searched.

Lucy found here

Question 15

• Kada Gona

Answer 15

• Previously oldest stone tools 2.6 million years ago

Question 16

• What is a Continental Rift?

Answer 16

• A linear zone along which continental lithosphere stretches (and thinned) and pulls apart. Its creation may mark the beginning of a new ocean basin
• Tensional forces and buoyant uplifting of the heated lithosphere cause the upper crust to be broken along normal faults, while the lower crust deforms by ductile stretching.
• As the crust is pulled apart, large slabs of rock sink, generating a rift valley
• Further spreading generates a narrow sea
• Eventually an expansive ocean basin and ridge system are created.

Question 17

• The East African Rift

Answer 17

is a continental rift that extends through eastern Africa for approximately 2,000 miles. It is made of several interconnected rift alleys that split into eastern and western sections around Lake Victoria. Eventually, a section of Africa will be divided by ocean.

Question 18

• What causes Rifting?

Answer 18

• Mantle Convection
• Plumes
• Slab Pull and Ridge Push (subduction)
• Gravitational Collapse
• Started 24 MYA
• Rift in Malawi opening at less than 3 mm per year.

Question 19

• What is the geological effects of the African Rift?

Answer 19

• Creation of a ocean basin.
• The opening of a new ocean basin begins with the formation of a continental rift. When rifting continues, the rift system evolves into a young, narrow ocean basin.
• Earthquakes.
• Any movement within a fault system can cause strain that builds up and result in devastating earthquakes
• Rift Volcanoes.
• Rift volcanoes form when magma rises into the gap between diverging plates.

Question 20

• Fossil Hominid Sites of South Africa The Taung Skull Fossil Site

Answer 20

• :
• 1924 the celebrated Taung Skull – a specimen of the species Australopithecus africanus – was found
   Makapan Valley, also in the site, features in its many archaeological caves traces of human occupation and evolution dating back some 3.3 million years
   Fossils found there have enabled the identification of several specimens of early hominids, more particularly of Paranthropus, dating back between 4.5 million and 2.5 million years, as well as evidence of the domestication of fire 1.8 million to 1 million years ago

Question 21

The Earliest Fossil Hominins

Answer 21

 Extinct or fossil species that are linked to us.
 A couple of important terms:
 Plesiomorphic Trait A primitive trait inherited by a species from their ancestor.
 prehensile feet in living apes
 Apomorphic Traits New or ‘derived’ trait. It first appears in the species in question. Not inherited from an ancestor. E.g. Early Miocene apes had no tail. Likely as they were in trees less so didn’t need it. They did evolve from monkeys with tails tho.
 no tail in primitive apes- no tail in humans.
 non-prehensile feet in later hominins

Question 22

 Plesiomorphic Trait

Answer 22

A primitive trait inherited by a species from their ancestor.

Question 23

 Apomorphic Traits

Answer 23

New or ‘derived’ trait. It first appears in the species in question. Not inherited from an ancestor. E.g. Early Miocene apes had no tail. Likely as they were in trees less so didn’t need it. They did evolve from monkeys with tails tho.
 no tail in primitive apes- no tail in humans.
 non-prehensile feet in later hominins

Question 24

When researchers dig up a new fossil …

Answer 24

 They need to decide if it is … ??
 Where does it fit into our evolutionary tree?
* just another example of something we’ve already found before?
* or a new species?
* or even a new genus?
* Need to study the features of the fossil.

Question 25

 Evolutionary Systematics

Answer 25

process of constructing the evolutionary relationship of the fossuls.

Question 26

 Phylogeny

Answer 26

refers to the actual evolutionary relationships between different organisms.

Question 27

 taxonomy

Answer 27

the process of classifying organisms, based on available data, about their phylogenetic relationships  With living organisms (and a few fossil species) we can use DNA to get a more accurate idea of actual evolutionary relationships (as we saw with the living primate taxonomy) gives us almost 100% confidence. But for super old ancestors, we do not have DNA.  This is mainly based on how different or similar two fossils are in their morphology – e.g., what plesiomorphies do they share and what apomorphies distinguish them? * different groups in the taxonomic system (different species or different genera) are referred to as different taxa (singular = taxon) 

Question 28

Pliocene

Answer 28

Genus Homo (hablis) The Pliocene is a geological epoch that occurred from approximately 5.33 million to 2.58 million years ago, preceding the Pleistocene epoch.

Question 29

Pleistocene

Answer 29

Genus homo turn into homo erectus, neandertals 2.6 MYA to 12k years ago

Question 30

Holocene

Answer 30

started 12000 years ago- switch from hunting and gathering to farming etc.

Question 31

writing starts?

Answer 31

Last half of Holocene

Question 32

The last 7 million years … Important geologic time periods

Answer 32

 The last 7 million years … Important geologic time periods: The last 7 million years of Earth's history fall within the Quaternary Period, which is part of the Cenozoic Era. The Cenozoic Era began around 66 million years ago and continues to the present day. The Quaternary Period is characterized by the presence of repeated glaciations, and it is divided into two epochs: the Pleistocene and the Holocene. Pleistocene Epoch (2.58 million years ago - 11,700 years ago): The Pleistocene is often referred to as the Ice Age. During this epoch, Earth experienced multiple glacial and interglacial cycles, with ice sheets advancing and retreating. These climatic fluctuations had a significant impact on the landscape and the evolution of life. Holocene Epoch (11,700 years ago - present): The Holocene represents the most recent geological epoch and is characterized by a relatively stable and warmer climate compared to the Pleistocene. It encompasses the time since the last major ice age, and it includes the development of modern human civilizations. The Holocene continues into the present day. These geological time periods are part of a hierarchical system used by geologists to categorize Earth's history based on significant events and changes. The Quaternary Period, with its Pleistocene and Holocene epochs, captures the environmental and biological developments of the last 7 million years.

Question 33

Hominid’ vs ‘Hominin’

Answer 33

Hominid: Historically, the term "hominid" was used to refer to all members of the biological family Hominidae. This included not only humans but also great apes such as chimpanzees, bonobos, gorillas, and orangutans. In this broader sense, hominids encompassed all the great apes and their ancestors. Hominin: The term "hominin" is a more specific and modern classification. It is used to describe the tribe Hominini, which includes modern humans (Homo sapiens) and our closest ancestors after the split from the common ancestor with chimpanzees. In other words, hominins include all species more closely related to humans than to chimpanzees. The key distinction is that "hominid" includes a broader group that comprises both humans and great apes, while "hominin" is a more narrow classification specifically referring to humans and their closest extinct relatives.

Question 34

* Quaternary period

Answer 34

* Quaternary period is what has the Pleistocene and Holocene epochs.

Question 35

Hominini

Answer 35

the tribe level which we separated from apes. * Chimps and bonobs and us come from Panini. Use chimp as an analog for what early homnin used to look like.

Question 36

 Chimpanzee post-crania:

Answer 36

 Unlike us  * long arms  * short legs  * long, narrow pelvis  * legs widely spaced  * long narrow fingers/toes  * prehensile hands and feet  * narrow from side to side, deep from front t back rib cage  Chimpanzee cranium: * brain size: 300-400 cc  * robust browridge  * alveolar prognathism- lower face protrudes.  * canine pillars- bony structure in bower face- provides support for powerful bite.  * u-shaped tooth row  * small molars & premolars – only slightly larger than ours.  * large incisors  * very large canines w honing complex (when close mouth upper caninie is sharpened against the premolar)- especially upper and in males.  Last 8 million years- most important- we split from apes.

Question 37

 Sahelanthropus tchadensis

Answer 37

Sahelanthropus tchadensis is an extinct hominid species that lived approximately 7 million years ago during the late Miocene epoch. The fossilized remains of Sahelanthropus were discovered in Chad, Central Africa, at a site known as Toros-Menalla. 7 mya “Toumai” means hope of life. South sarahan desert in Chad. – 7 MYA- around the time of homonin chimp split. Has ape like face and small brain- comparable to chimps. Could be a chimp ancestor. Do not know how bipedal it was. Nuchal line on back of skull- where neck muscles attach to cranium. This muscle is larger and attaches higher on skull if they are quadrupeds. In humans it’s a little lower. But Toumai may be bipedal based on the location of the nuchal muscle.

Question 38

 Foramen magnum

Answer 38

- related to posture- humand in centre of base of skull- because we stand upright. Quadruped has this at back of skull. Chimp is halfway between. Toumai is kinda in the middle of humans and chimps so not sure if bipedal.

Question 39

Orrorin tugenensis

Answer 39

… an obligate biped? ≈ 6 mya East Africa A more habitual biped than chimps and bonobos ..Around the time of ape-human split.  Similar length to chimps- but was likely more bipedal than chimps based on bones in leg. Cant say for sure, need more fossils. Good candidate for being early hominin.  From 5 to 1 mya (million years ago): another important hominid species in the study of human evolution. It lived approximately 6 million years ago during the late Miocene epoch. The fossilized remains of Orrorin were discovered in the Tugen Hills of Kenya, East Africa. one of the oldest known hominids. It dates back to around 6 million years ago, placing it in the late Miocene epoch. considered by some researchers to be a potential candidate for a common ancestor of humans and chimpanzees. Its bipedal adaptations and age make it an important species for understanding the early stages of hominid evolution.

Question 40

 4 genera and up to 20 species (we’ll just look at the major ones) our direct line

Answer 40

 Ardipithecus: Ar. ramidus  Australopithecus: A Anamensis, a. afarensis. A. africanus, A sediba  Paranthropus: P boisei, P robustus, P aethiopicus  Homo: H. habilis, H ergaster, H. erectus.

Question 41

 Ardipithecus ramidus

Answer 41

4.5 mya. Discovered in 1992 in Ethiopia. Much larger than chimp cranium. Brain similar size to chimp 300-400 cubic cm. Large incisors, molars are rectangular- which is apelike. Reduced ale ho prognathism protruding face. More bipedal.  Strongly arboreal- prehensile feet.  ATM oldest hominin ancestor  Reduced ‘prognathism’

Question 42

Australopithecus anamensis

Answer 42

4.0 to 3.0 mya East African Species. First found my Maeve Leaky in 90s. no complete crania. Small brain 370 cc. Apelike cramium and dentition. Large caniniens, signifigane sexual dimorphism.  Lower leg bones- tibia, indicates bipedal and no prehensile feet.  Apomorphic features?  Feet that are no longer prehensile Lower leg (tibia) Apomorphic features? Fully obligate bipeds

Question 43

Australopithecus afarensis- Australopithecus africanus

Answer 43

≈ 3.0 - 2.4 mya South likely our direct ancestor. East Africa  African Species  afarensis and  africanus- sputh African species.  Both had small bodies, dexual dimorphism- males are 30% larger than females. 110 cm vs 140 cm. likely lot so fo competition for females.  Both craniums are about 425 cc. not much bigger than chimp and less than 1/3 the size of our brains.  Canini diastema (diastema, or a gap, between their canines and adjacent teeth) disappears in all hominins after this.

Question 44

Australopithecus sediba ?

Answer 44

2.0 mya South African Species (Malapa)- not called species till 2010. Malapa 1- young boy Malapa 2- adult female. 420 cc brain, 130 cm tall. Fossils spread out in the breccia- not sure if all the bones are just these 2 individuals. We are unsure of this. Could be a mish mosh of other species and that’s why they look new.

Question 45

 Australopithecus africanus

Answer 45

≈ 3.0 - 2.4 mya South African Species  afarensis and africanus  ‘Dental Arcade’  Chimpanzee- U-shaped  A afarensis /africanus- U-shaped  Modern human- Parabolic  Their dental arcade is much larger than us.  Increase in size of molars are important.  Some important changes in the hands and wrists- more human like less apelike.  Facultative bipeds-  Obligate bipeds- the femus neck has a bigger dent thing and angle- makes a big difference in how legs work.  Afraensis and africanus have pelvis more like us, chimps have a bigger pelvis with huge range of motion compared to us. Ours have legs that swing forward and back, chimps they can go side to side.  Walking gait, chimps have awkward gait when bipedal, but ours is easy cuz of the forward back motion.  Laetoli footprints- differences in weight distro, but they had an almost modern foot and were likely obligate bipeds. It started with them then continued to later hominims.

Question 46

Australopithecus africanus fossils

Answer 46

 Taung Child a africanus.  “Mrs. Ples” a africanus- see traits you done see in other species. Appearance of bone structures related to chewing. Prominent canine pillars. Good candidate for a step on the branch leading to next species. Likely afrenses iwas ancestor of africanus.

Question 47

A afarensis. fossils

Answer 47

 “Lucy” – 3.2 mya – partial skeleton – Hadar, Ethiopia, A afarensis.  “Kadanuumuu” – 3.6 mya – adult male – north of Hadar region a afarensis.  “Selam” – 3.3 mya – mostly upper body – 3-year-old child – Hadar region A afarensis. Well preserved and helped shed new light on this species.  Afarensis upper body: evidence of tree climbing abilities- finger bones are a bit curved, means they were better at it than us. Scapula- similar to huma but greater range of arm movement, more like ape. Inner ear bones- keep balance. Apes have them shaped different for trees- Salems indicated adaptation to tree climbing.

Question 48

 Conclusions about A. afarensis and A. africanus

Answer 48

 Obligate biped, but still spent a lot of time in the trees. Not as arboreal as others. Likely slept in trees and hid from predators. Could be a direct ancestor for us.

Question 49

 Paranthropus aethiopicus

Answer 49

2.5 mya Sagittal Crest Flaring cheek bone  the “Black Skull” discovered inkenya in 1985  410 cc brain.  Large molars  Masticatory apparatus.  Temporalis muscle, massaer muscle.  Saggital crest- on top of head.

Question 50

 Paranthropus boisei

Answer 50

2.3 to 1.2 mya East African Species  Very strong bite, more like gorilla.  Megadontia’  Possible version of tree:

Question 51

Paranthropus robustus

Answer 51

2.0 to 1.0 mya South africa  120 cm and 35 kg for female  140cm and 50 kg for males. Cranium differs them from the other species. Smaller teeth than africanus. Increase in molar size. Strong mandible, powerful jaws. 520 cc brain. Big increase considering that they are still small bodied. Drimolen 70 female no sagittal crest, 415 cc brain. Drimolen 155 Male 450 cc brain, large sagittal crest Sexual dimorphism. Megadontia- mega sized teeth.

Question 52

Paranthropines- seems to be a dead end- did not branch from there.. why?

Answer 52

Too specialized, the were not broadly adaptable. Die out when change happens

Question 53

Miocene

Answer 53

end of Miocene 8-5 mya- this is when hominin appears and diverges from the other ape lineages.

Question 54

* Origins of our genus Homo?

Answer 54

* Many researchers think Australopithecus afarensis is a direct ancestor to our genus homo- but no consensus and we cant be sure- currently no other reasonable options.

Question 55

* Homo habilis

Answer 55

2.8–1.5 mya Mainly East Africa … maybe South Africa too? Currently appears to be the root of the genus tree. Koopbi Fora in Kenya. * This means that homo hablis overlapped with Paranthropus and Australopithecus. * The first fossils found are called ‘holotype’ fossils. Fossil # 7 in Oldavei George. (type fossil) * Was controversial to assign this fossil to the genus homo. * Cant tell male from female fossils- less sexual dimorphism than Australopithecus and paranthopenes. * More similar to genus homo with small teeth and what not. .

Question 56

* Homo Rudophensis.

Answer 56

a proposed hominin species that is known from a few fossil specimens discovered in the Koobi Fora region near Lake Turkana in Kenya. The fossils date to around 1.9 million years ago. The taxonomic status of Homo rudolfensis is somewhat controversial, and it is considered by some researchers to be a variant or a different population of another hominin species, possibly Homo habilis.

Question 57

Intermembral Index

Answer 57

Arm length/leg length x 100 * If your arms are half the length of your leg then the index is 50. * Chimps = 105-110 arms are lightly longer than legs. * Australopithecus/ Paranthropus= 85-95 * H. habilis= 80 – higher than us but lower than above. * Homo sapiens= ≈70 interfemoral index. * Presume as we became more efficient bipeds this evolved, less tree climbing

Question 58

* Fossil 1813 from Koobi Fora, Kenya

Answer 58

cranial capacity of 510 cc. more than paranth. etc. * contributes to our understanding of early human evolution and has been attributed to Homo habilis. This fossil offers insights into the brain size and morphology of early hominins,

Question 59

* “Twiggy” Fossil 24 from Olduvai Gorge

Answer 59

1.8 mya- cranial capacity 590 cc. above average for the paranthopenes * This fossil is believed to belong to Homo habilis and contributes to our understanding of the physical characteristics and brain sizes of early hominins. The relatively larger cranial capacity of this specimen indicates an advancement in brain size compared to earlier hominin species.

Question 60

* Fossil 1470 from Koobi Fora

Answer 60

1.8 mya- missing all its teeth. 775 cc brain size. * significant find attributed to Homo habilis. It's characterized by having a relatively large cranial capacity compared to other fossils of similar age, marking a crucial point in the understanding of early human evolution. This fossil, dated to around 1.8 million years old, has a brain size of approximately 775 cc. Its brain size and other physical features align more closely with Homo habilis than other contemporary species, such as Paranthropus. * Upper and lower jaws- 4th fossil. The lower jaw is not complete so able to reconstruct the other half since they are symmetrical. Both fossils are from Hadar but from different locations and different individuals.

Question 61

* Hadar, Ethiopia

Answer 61

* very small teeth * more ‘modern’ looking than australopithecines and paranthopenes. * The upper jaw is 2.3 mya and is the oldest fossil we found so far. * likely corresponding to an ancient, transitional form possibly leading to the emergence of the Homo genus. The description of "more modern" features and smaller teeth could indicate a transitional stage between earlier australopithecines and the genus Homo. These fossils could represent a common ancestor or an early offshoot of the Homo genus, but they are not specifically identified as Homo habilis.

Question 62

* 3 traits that distinguish Homo habilis from the Australopithecines and Paranthropines

Answer 62

made it clear that homo hablis was transitional to later homo species: homo erectus and homo egaster. 1) Increased Cranial Capacity- mean of 650 cc- more than 100 cc larger than paranthopenes who were larger than australopithecines. Did not increase in body size. Homo hablis degree of encephalization is greater than the aust and parant. Making it closer to where we ended up. * Smaller Teeth Overall- more parabolic dental arcade. hablis has smaller molars and a parabolic dental arcade: U-shaped configuration of the dental arch in the mouth. It's a more rounded dental arrangement compared to the rectangular or "V" shape observed in some other species. This dental arcade is characterized by a curve that is wider at the back and narrows towards the front of the mouth. This structure is notably found in some early humans like Homo habilis, distinguishing them from other hominin species with a different dental arrangement.Flattening of the face and reduced pragmatism. 2) More Advanced Precision Grip. Homo hablis has modern-looking hands. Power grip: used to hold a hammer- precision grip, more intricate for tool making. Distal phalanges – small fingertip bones. and apical tufts are more like us. Chimps have pointy apical tufts, ours are flat and wide. H hablis similar to ours. Paranthpos has slightly expanded aplicat tufts but not the austrolipithicans. Increased precision and dexterity- manufacture of stone tools- perhaps we will evolve back to having pointed tufts to aid in tapping tiny keys on our iPhones. 3) Very Modern-Looking Feet. The feet of aust and paranth are already similar to ours, homo hablis is more similar to us. Olduvai George 8- full h hablis- able to compare to modern foot. Compared to chimps and to us, we see an enlarged big toe designed for bipedal walking and carrying more weight.

Question 63

* Trends in tooth size:

Answer 63

Ardipithecus ramidus and A. anamnesis had Smaller molars (like chimps and like us. ) * With Australopithecus aferensis we see a big jaw & big molars A. africanus: a big jaw & huge molars Paranthropus aethiopicus: huge jaw & megadontia * Dead end p boisei and p robustus we see massive jaw & megadontia! Homo hablis around 3 million years ago smaller jaw & molars than afarensis (not far off chimps and us) * Ardipithecus ramidus and A. anamnesis: These species had smaller molars, similar to both chimpanzees and early humans. They had a mix of characteristics that resemble both our common ancestors and some modern-day primates. * Australopithecus afarensis: Displayed a larger jaw and bigger molars. This species was a likely ancestor of the Homo genus, including Homo habilis. * Australopithecus africanus: Similar to A. afarensis with a big jaw and huge molars. * Paranthropus aethiopicus: Exhibited an even more pronounced increase in jaw size and massive molars, termed "megadontia." * Paranthropus boisei and P. robustus: Both these species demonstrated a further increase in jaw size and megadontia. They are considered a separate branch from the Homo lineage and were evolutionary dead ends. * Homo habilis: Around 3 million years ago, Homo habilis emerged with a smaller jaw and molars compared to afarensis, falling somewhere between the dental characteristics of chimpanzees and early humans. This is suggestive of a shift in diet and adaptations. * The decrease in jaw and molar size among Homo habilis and the transition towards a more human-like dental pattern might signify dietary changes or adaptations that took place during that period. The shift from the larger, robust jaws and megadontia seen in Australopithecus and Paranthropus to the smaller, more modern dental characteristics in Homo habilis may coincide with changes in diet, tool use, or other adaptive behaviors

Question 64

* Apical tufts

Answer 64

in the context of hand morphology, refer to the tip of the finger bones or phalanges. They are small projections found at the ends of the fingers. These tufts play a role in the mechanical support and functionality of the fingertip. * In the case of Homo habilis, their apical tufts are considered to be more similar to those of modern humans rather than those of other earlier hominins. Chimps, for instance, have different-shaped apical tufts compared to humans. The differences in the apical tufts of various hominin species often reflect variations in their dexterity, grip, and tool-manipulating capabilities.

Question 65

feet of Homo habilis

Answer 65

more similar to modern human feet compared to those of Australopithecus and Paranthropus. Specifically, Olduvai George 8, a full Homo habilis foot specimen, enabled comparisons to modern human feet. One significant feature is an enlarged big toe that facilitated bipedal walking and bearing more weight, which is a distinctive characteristic of human feet. This structural adaptation likely supported their mobility and stability while walking on two legs. * Fully adducted big toe:

Question 66

* Fully adducted big toe:

Answer 66

means it's parallel to other toes, unlike chimps.

Question 67

abbducted big toe.

Answer 67

Diverges from the foot at an angle

Question 68

* Human and H. habilis foot

Answer 68

Double arch- large heel bone. Longitudinal arch and transverse arch. Complex arch system means that their foot is mechanically set up for efficient weight transfers from the toes to the heel etc. important for obligate bipedalism

Question 69

* Homo habilis means

Answer 69

stems from thinking that the species was the 1st to make stone tools. Oldest fossils used to correspond to what is known as oldest stone tools:

Question 70

stone tools first appear?

Answer 70

* 2.8–1.5 mya 2.6 mya stone tools at Kada Gona * The appearance of stone tool technology – but now we found evidence for much older stone tools. * Simple stone tools at 3.3 mya (Turkana eknya )? * cutmarks on 3.4 mya animal bone (Hadar) * This means that the earliest tool makers must have been the Australopithecines.

Question 71

appearance of stone tools, explained

Answer 71

suggesting that this species was the first to use and make stone tools. The current understanding has extended the timeline for stone tool usage further back in time. For instance: * Stone tools were found at Kada Gona dating back to 2.6 million years ago, attributed to the period of 2.8–1.5 million years ago. * Later findings have revealed evidence of even older stone tools, with simple stone tools discovered at Turkana, possibly around 3.3 million years ago. * Moreover, cut marks on a 3.4-million-year-old animal bone at Hadar suggest the use of tools or some form of processing, further pushing back the timeline for early tool use. * The expanding age range of these archaeological finds suggests that stone tool technology may have been present and developed earlier than previously believed. The evidence found at these sites indicates that early hominins, including Australopithecines, were involved in producing and utilizing stone tools, thus linking them to the early phases of tool-making in human evolution. * At present, the oldest evidence of stone tool usage is associated with Australopithecus, particularly the Oldowan tool industry, which is attributed to this early hominin group. These tools are the earliest documented technology known to have been crafted and utilized by our human ancestors. This inference is based on the findings of tools associated with sites where Australopithecine fossils have been discovered.

Question 72

* Earliest and most simple stone tool technology.

Answer 72

Mode 1: The Oldowan Industry 3.4 to 1.5 mya Simple chopping tools and simple flake tools. This is the technology that Australopithecus, paranthapene and early homo species were using. Selecting nodules of suitable stone, without planning, struck with a hammerstone to make simple flakes to use for what task they needed. When done, they dropped it, when they needed more they would remove more from the nodule. Breaking open animal bones to get nutritious marrow out. * Explained: Oldowan Industry, categorized under Mode 1, represents one of the earliest stone tool technologies, primarily between 3.4 to 1.5 million years ago. It was used by Australopithecus, Paranthropus, and early Homo species. This industry was characterized by the creation of simple tools and flakes from stones. * Key points about the Oldowan Industry: * Tool Production: Individuals selected suitable stone nodules and used a hammerstone to strike these nodules, creating simple flakes that were suitable for various tasks. * Ad Hoc Use: Tools were used for immediate needs and then discarded, rather than being carefully planned or curated for future use. * Task Specific: The tools created by the Oldowan technique were used for tasks like cutting, scraping, or chopping. * Bone Processing: These tools were also used to break open animal bones to access the nutrient-rich marrow. * It's important to note that Oldowan tools represent a significant technological advancement as they reflect the earliest form of stone tool production. The development and use of such tools marked a significant shift in human evolution and the cultural adaptation of our ancest

Question 73

* Biocultural Evolution

Answer 73

The combination and interaction of human biological evolution and the evolution of our technology. As soon as our hominin ancestors started making tools it dramatically changed how we would evolve from then on which is called biocultureal evolution. Prior to lithic technology, our ancestors relied on teeth to kill prey animals and cut them up into small places to swallow. The stone tools replaced our canines and incisors. Our technology and anatomy evolved in concert to allow us to adapt.

Question 74

* Dual Inheritance Theory

Answer 74

: Most organisms just inherit genetically determined characteristics- eyes to see wings to fly and hooves to run. Humans inherit important adaptive traits through their genes … which allow us to survive and reproduce. … AND through social learning. Taught how to do certain things and make certain tools that allow us to do specific things and survive. Made us good at adapting to new conditions. We are very successful in the short time we have been around.

Question 75

* NARiOkOTOmE bOy

Answer 75

the remains of most of a Homo erectus skeleton, dramatically changed our understanding of early Homo. western side of lake Turkana between 1.5 and 1.6 million years ago comes the nearly complete and quite tall Nariokotome H. erectus skeleton of a boy

Question 76

genus Homo differs from Australopithecus

Answer 76

by hav-ing a larger, more rounded braincase; a smaller, less projecting face; smaller teeth; and eventually a larger body and shorter arms and perhaps more efficient striding biped-alism. * Made stone tools: most anatomists would argue that the species designation should be made on morphological, not behavioral, grounds * H. habilis included a range of smaller and larger brain sizes. * Toolmaking was first and foremost an adaptation to the environment of the late Pliocene

Question 77

* Dmanisi skulls:

Answer 77

: They are small brained (546–750 cc), very similar to early African H. erectus, differ in anatomy from H. habilis, linked to H. erectus by their premolar and molar tooth structure, the degree of development of their brow-ridges, and other cranial and postcranial structures. more similar to the early African H. erectus fossils than they are to early Asian H. erectus, health issues not normally seen in fossil crania: One is entirely toothless, show conclusively that early humans had migrated out of Africa at nearly the same time that H. erectus first appears in Africa.

Question 78

* Homo erectus appeared in Africa when?

Answer 78

Africa 1.8 to 1.9 million years ago and was the first homi-nin to leave the continent, probably by about 1.7 or 1.8 million years ago

Question 79

* Homo erectus brain size ranges

Answer 79

something less than 600 to 1,200 cc, averaging about 900 cc

Question 80

* H. ergaster vs H. erectus

Answer 80

* H. ergaster : East Africa ,Thinner cranial bones, Less pronounced browridges H. erectus: Asia. Thicker cranial bones More pronounced browridges

Question 81

* The earliest fossil evidence for H. erectus

Answer 81

koobi Fora in kenya 1.8 million years ago.

Question 82

* The old-est certainly H. erectus remains

Answer 82

largely complete cranium, kNm-ER 3733, dated at 1.63 million years old and with a cranial capacity of only about 850 cc Koobi forA

Question 83

The very first H. erectus fossil ever found—and thus the type specimen for the species

Answer 83

* Pithecanthropus erectus (“the upright ape-man”). This specimen, Trinil 2, also nicknamed Java man: * Pithecanthropus erectus (“the upright ape-man”). This specimen, Trinil 2, also nicknamed Java man:

Question 84

canine fossa

Answer 84

(an indentation on the maxilla above the canine root) has been used to argue that the Gran Dolina fossils represent a previously unknown hominin species, Homo antecessor, which may have been the common ancestor of both Neandertals and modern H. sapiens

Question 85

Characteristics that make is different from other mammals and even other primates.

Answer 85

Such large brains? (high degree of encephalization) * B/ Obligate Bipedalism? * C/ Reduced hair cover? * D/ role of Hunting and meat-eating?

Question 86

* Cranial Capacity, Body Mass, EQ

Answer 86

* Homo sapiens (female) 1300, 60, 5.2 * Homo sapiens (male) 1400, 75, 4.8 * Chimpanzee 350, 50, 2.2 * Gibbon 100, 6, 2.0 * Orangutan 380, 60, 1.6 * Baboon 150, 20, 1.4 * Gorilla 500, 120, 1.1 * Colobus monkey 7,5 9, 1.1

Question 87

Socialization Theory: (brain size)

Answer 87

Socialization Theory: * Most common theory * Complex social interaction required larger brains. Socialization is more cognitively demanding. Primate interaction is more complex than say wolves. All members need to have a good understanding of the relationships within the groups, politics, access to mates, all very complex. * E.g. who has shared with you, who has your back, who hasn’t competed with you? * Group social interaction is more cognitively complex than most other types of behaviour Successful navigation in social groups, requires each of us to monitor

Question 88

Socialization Theory: (brain size) 3 levels of complexity:

Answer 88

* 1/ our relationship with every other individual * 2/ the one-to-one relationships between all other individuals * 3/ these relationships are always changing typically on a daily basis.

Question 89

Hyper-cooperation!

Answer 89

* Carry out a plan that benefits all members. * Know what others are thinking- theory of mind. Able with nonverbal cues. * Put our individual goals on hold for the sake of the groups goals. Apes can’t, they focus on individual need and desires even when doing so might benefit them and the rest of the group. * We appreciate the benefits of bigger outcomes and can put our desires aside. * This likely made us so successful as a species. o Can improve adaptive success of all members of the groups. o Can do 10 times what an individual can achieve alone. Group efforts are greater than a sum of their parts. o Requires a high degree of intellect and encephalization o Early hominins who happen to have slightly larger brains would have a bit of a higher degree of cooperation and survival and pass on their genes. o The benefits of the larger brain would pass down in natural selection.

Question 90

Complex Language Theory: (brain size)

Answer 90

* Language goes hand in hand with complex social behavior * Cooperative hunting or teaching parent to child. * But hunters rarely talk when hunting. Do not want to scare away the animals. These hunters don’t need to talk as they know how it works. * Teaching and learning is more plausible. Language is an important component of teaching and learning, especially for complex ideas. * Popular area of research, don’t know if language is the goat. * Language allows individuals to more accurately and directly express their desires and intentions * Verbal socialization is most common and complex in the campsite where silence is not required. * GO back to the first theory- language helps complex social development. * Key to successful socialization is to know gossip which is important and a big part pf understanding our place in social groups and the state of our relationships.

Question 91

* Dissembling

Answer 91

similar to lying- say something contrary to what you think and feel- and may express in body language. o Want to fool others for some reason, e.g. having a bad day, when someone asks you say fine, makes life run smoothly. o This is a level of complexity though that is complex and requires complex language. o Carry out complex social politics, convince people of your intentions, even if you don’t feel that way inside Did complex language develop to help us dissemble?.

Question 92

Other major advantages of language:

Answer 92

* discuss things that are not present – animals or people that are not there in front of you * talk about past and future * discuss abstract concepts kinship systems and religion * store information collectively – lock knowledge into the collective mind of a group * supercharges cultural transmission – the passage of knowledge between individuals and the rate of innovation of new ideas/technologies allows groups to adapt more quickly and successfully. What plants are safe, how to start a fire, how to make better hunting weapons. * Increase the rate of innovation and technologies within groups.

Question 93

* The Problem with the Language hypothesis

Answer 93

when did complex language appear?? * Language could have encouraged more cognition. * Language requires impressive cognitive abilities. * The general encephalization trend started before language started. * Maybe the development of language explains the jump in brain size about 2 mya. * Some think that australophicines and paranthopenes had complex language like is- very few.

Question 94

when did Obligate Bipedalism appear?

Answer 94

4 mya.

Question 95

Problems: bipedalism

Answer 95

slow, quadrupeds are much faster than us. We couldn’t outrun these predators and likely lived in forests so we could hide in trees. Quadrpeds have been developing for 400 mya. Homininds still have same structure but turned it around resulting in chronic back problems. Back pain is 2nd to the common cold among reasons for clinical visits.

Question 96

theories formed for why bipedalism

Answer 96

1. Tool Use (traditional theory) And also consider … the importance of throwing in hominin adaptations … and incredible dexterity of human hand and how important this is to us? Walking on hind legs freed up our hands for tool use- Darwin thought this. But it predates stone tools by half a million years. Expecting to find evidence of stone tool use before this. Also, other tools like sticks and stuff like chimps do. We would not know as they would biodegrade. Also throwing ability of humans and the importance of throwing in hunting. Dexterity of human hand: important role in making fire and making warm clothing, could this have developed independent of bipedalism? Tool use is a strong candidate. 2. Thermoregulation (regulating core body temperature) For several million years East Africa become drier and forests were replaced by open grasslands. Forests shrunk and were replaced by savannah. (Peter Wheeler 1991). For years it was thought this occurred around the same time that bipedalism developed among early hominins. It is thought that since the forest biome was gone that they would move into open habitat and be in the sun, so thermoregulation would have been important. Bipedalism offers advantages: reduce surface area of body that is exposed to sun, standing its just top of head and shoulders directly exposed. Also most of body mass is higher, air is warmer near the ground, as well as air circulation. Bipedalism predates this change though so this theory is crap. Early australopithecines were living in the woods. 3. Efficiency of Locomotion (energy usage) Modern sprinters: * Men’s highest speed is 45 kph * Women’s highest speed is 37 kph * Average person’s speed is 25 kph * Cheetah = 95 kph * Gazelle = 95 kph * Elephant = 40 kph Large animals that we would want to hunt can outrun us. When in motion, its about efficient energy use. We all use energy just standing still. When quads start moving, they must expend some energy to bear body weight and create forward momentum. As they move to a walk then a run, the use of their energy becomes more efficient. They still use it up but can cover long distances. Hominins become more efficient as we walk. We don’t use much more energy walking or jogging than we do standing still. But we are inefficient when running at high speeds. Low velocity running and walking is very energy efficient.

Question 97

Reduced Body Hair Cover, why?

Answer 97

* We are not the only mammals with limited hair coverage, but our skin is thin unlike elephants. * We have similar body hair to chimps and bonobos but our hair is small and fine so it doesn’t look like we have that much hair. * highly variable in modern humans. Humans have many more eccrine glands (2-5 million) body hair thickness is a plastic trait and can likely change quickly thru selection. * We think there is a link between less hair and more sweating * Mammals have 2 main types of sweat glands: * sebaceous (secrete oil) * eccrine (secrete H20) much more effective cooling system than other mammals Tied to development of whole-body transpiration (sweating): very effective thermoregulation system in hot, dry climates. * Effectiveness of sebaceous glands is limited. * We can be active when other animals have to chill. When did this occur? * “This hyper-efficient thermoregulation physiology is likely tied to hominins moving from forests to living in open environments …… and the development of modern body proportions. (Nina Jablonski) * This would be H. ergaster around 2 mya

Question 98

Thermoregulation benefits of a larger body?

Answer 98

* Larger bodies lose water faster than smaller bodies in hot weather. * H20 loss in hot environs ( 35 to 40°) and potential foraging range * Works even better with a tall, narrow body shape (Homo ergaster) * This does coincide with he shrinking forests around 2 mya. * But, increased exposure of bare skin to sunlight (UV radiation) would require some sort of skin protection: increased melanin production … = darker skin tone * This is why people living in equatorial regions have dark skin, and this would have happened as we lost our hair.

Question 99

Thermoregulation AND Efficiency of Locomotion

Answer 99

We can outrun quadrupeds if we pace ourselves, they will collapse and die but we can keep going. Chasing an animla when it gets tired and we don’t is persistence hunthing.

Question 100

Early hominins hunting and meat eating?

Answer 100

* Hunting would potentially explain two major trends in hominin evolution discussed earlier: similar to tool use hypothesis. * Bipedalism: Freed up the hands for the manufacture and use of hunting weapons? * Encephalization: A need for increased cooperation and communication to be successful hunters led to a larger brain? Early ideas about hunting in hominin evolution Reduction in Canine Size A response to the increased role that tools took on: “tools used for hunting/butchering replaced big canines” * The ‘Hunting Hypothesis’ Anatomical/physiological and behavioural changes: * Reduction in canine size- response to increased role that tools took on for butchering and hunting. * Increased Hominin Body Size especially with Homo ergaster/erectus. Larger body would allow hunters to be more effective hunting larger species. There was a larger body size that happened when we moved from arboreal to terrestrial. Moving from forest to other environments could result in bigger bodies as you need a smaller body to be in the trees and less thermoregulation. * Larger body made hominins more effective at hunting larger prey species

Question 101

Behavioural changes: hunting

Answer 101

* Division of labour based on sex: “men hunted and women had babies” but this isn’t always true. * Food Sharing Hunters brought their kill back to the camp for sharing among the group. This does seem true, monkeys and apes like to get their own food. Could be logic to this idea. * Furthermore, if females were dependent on males for their food supply it might explain 2 notable human physiological traits: * Constant sexual reception among human females Unlike other primates (except bonobos), human females are not necessarily only receptive to sex around the time of ovulation we do it regardless of our cycles. * Concealed ovulation and monogamy Unlike non-human primates (except Vervet monkeys), among modern human females there are no obvious, outward physical signs of ovulation. Males do not know who was ovulating at any one time. Hunting hypothesis argued that this would keep the males cooperating as they were not as competitive over ovulating females.

Question 102

Changing views on the importance of hunting and meat eating?

Answer 102

* In past decades primatologists noted that: * Meat only was 25% of the diet the rest was plants. * Plants were collected by woman. * didn’t fit well with man the hunter. * 1960/1970s research among modern huntergatherers: * Active hunting may have been rare among earliest hominins. * … Recent opinions have swung back somewhat: * Scavenging meat Views from 1960s/70s were based on marginalized hunter-gatherer societies (Hadza, !Kung-San, etc.) . * Lots of archaeological evidence that meat has been important for at least 2 million years: * bones of butchered animals … * … with cut marks from stone tools … * … lying next to stone tools. * PLUS: bone chemistry analysis: they were eating a lot of meat. * Meat has been important for over 2 m years. * Humans are omnivores, but our digestive system is more similar to a carnivore’s than to a herbivore’s: * * our complete digestive system is very short * * relatively short small intestine (as proportion of entire system) * Sheep digestive system is 27 times the length of its body. * Wolves are 5/6 times the length of the body, food passes rapidly and protects them from dangerous microbes. * Humans is 5 times the length of our body. * Also, recent data on Chimps and Bonobos meat eating- small proportion of their diet and they prefer meat over plant foods. * Making crude spears and hunting bushbabies. * Our digestive system is very similar to Chimps’ and Bonobos’

Question 103

Expensive Tissue” Hypothesis

Answer 103

: Meat-Eating and Encephalization (Leslie Aiello and Peter Wheeler 1995) We need the meat to power our very large brains. Ø An organism’s body produces only a finite amount of energy to run all its various components (11 systems that all need calories). * Each system takes energy from the body’s reserves so must provide some adaptive advantage to be worth it. Example: eyesight Ø good return on the energy is uses, good adaptive returns. - cave salamander has no eyes because it doesn’t need to see its in a dark cave, no adaptive returns. . * Body size- large needs more food. Environment- hills or cold weather? Metabolism: how fast? Source of nutrition: how good is it? * The brain is one of most metabolically expensive organs Ø We dramatically increased ours over the past 3 million years. The brain uses 22 times as much energy as muscle tissue. * our physiology had to change to accommodate this: § need to balance our body’s energy needs with energy production/availability * Cannot increase gut size (simply eat more food) because the gut is as expensive as the brain * Hominins actually evolved a smaller gut, which helped to free up some energy, but we still needed a lot more to support our huge brain. * Hominins had to switch to higher quality diet: Meat: protein and fat. Fat and protein are easier to break down, provide higher net energy return. More calories are left over after digestion. * Seeds and nuts require more energy to get them than meat. * Meat comes in large packages, best return on collection efforts. Can eat whole animal and get bone marrow. * Continued research on this: importance of fat in hominin diets. Could be a good reason they left for colder climates as the animals are lean af on the savannah.

Question 104

The ‘Cooking Hypothesis’ (Richard Wrangham)

Answer 104

* “Discovery of fire and cooking food supported a larger brain. “ * cooked food digests much more efficiently = increases energy returns * We do not need to cook all or our food, but we need to cook some to maintain energy levels and long term reproductive success. * Modern humans have to cook some food: “raw foodists” experience amenorrhea and low sperm counts * “Cooking explains jump in H. ergaster encephalization around 2 mya.” * However, archaeological evidence does not support such an early appearance of regular use of fire. * If fire started that long ago there should be more sites with fire. * Low # of sites with use of fire use. Even use of fire 250k years ago is thin. * Need to cook could be a more recent development. * Could not have been just a jump in brain size since egaster, yes it occurred rapidly but was also fairly smooth.

Question 105

* 2 species follow Hablis in homo line

Answer 105

erectus and Ergaster.

Question 106

* Homo ergaster Appeared ?

Answer 106

in Africa ≈2 million years ago appeared first and homo erectus appeared shortly after.

Question 107

* Home Erectus spread

Answer 107

the first to spread to East Asia and Europe. * Never made it to Australia or the Americas.

Question 108

* Both Ergaster and erectus first appeared in Africa, who left first?

Answer 108

* Homo ergaster left Africa First

Question 109

* Time spans for H. ergaster and erectus

Answer 109

* H. ergaster appeared in Africa 2 mya and … * H. erectus appeared in Africa 1.6 or 1.7 mya. * H. erectus continued in: * Africa until 600,000 years ago * Asia until 100,000 years ago?? * Europe until 500,000 years ago * However, today, all European fossils that were once called Homo erectus have been given different species names. We don’t have any specific erectus fossils in Europe, even though species that were there were likely some form of Erectus.

Question 110

* ‘lumpers’ versus ‘splitters’

Answer 110

Lumpers- highlight similarities between fossils, so see fewer differences between them and fewer categories and genera. Splitters see the differences between fossils. See fossil record composed of a greater # of categories.

Question 111

Anagenesis.

Answer 111

Anagenesis is a concept in evolutionary biology that refers to a form of evolutionary change within a single lineage over time. Specifically, anagenesis involves the transformation of a species into a different species without the branching or splitting of lineages that is characteristic of cladogenesis (the formation of new species through branching events). Anagenesis is contrasted with cladogenesis, where new species arise through branching events, leading to the coexistence of multiple lineages Hablis-->ergaster/erectus likey NOT anagenesis. Ergaster and Erectus overlap in time. So more likely Ergaster evolved from Hablis, and then after a few hundred thousand years, Erectus emerged in Africa as a separate lineage * ergaster continued for a short period, while Erectus continued for much longer in Africa and Asia and is the ancestor for later species.

Question 112

* ancestor-descendent Divergent Evolution

Answer 112

refers to the process by which two or more related species become more dissimilar over time due to different environmental pressures or selective forces. Ancestor-descendant divergent evolution specifically involves a common ancestor giving rise to two or more descendant species that evolve in different directions. most likely what happened between erectus/ergaster when they evolved from Hablis.

Question 113

* H. ergaster/erectus Typical Features:

Answer 113

* We would recognize them as our ancestors if we saw them today. Similar: * Postcranium (trunk and limbs) Modern human proportions: * arm: leg (Intermembral Index = 70) * leg: torso like ours. * Lower leg: upper leg: like ours. * One big difference is robusticity. They have thicker limb bones. * Thick-walled bones

Question 114

* Average height for H. ergaster/erectus vs * Average height for modern humans

Answer 114

* Average height for modern humans ?? * 172 cm for males * 160 for females * Average height for H. ergaster/erectus * 165 cm for males * 153 cm for females * Ergaster and Erectus were perhaps 5 cm shorter than us on average.

Question 115

where is there a difference between ergaster and erectus?

Answer 115

* Cranial features are where there is a difference between H Ergaster and Erectus. * Erectus has thicker cranial bone than Ergaster. Both are quite thick compared to us * Thick cranial bone: this is a big difference between us. * Homo Erectus has a thicker brow ridge than Ergaster.

Question 116

Brain size, ergaster and erectus

Answer 116

- when looking at them collectively: Cranial capacity: mean = 900cc- * Third feature where erectus and ergaster differ- cc * * ergaster = 850 * erectus = 1000 * Ergasters brain is notably larger than Homo Hablis (850 cc compared to 650cc) * Erectus: This is starting to get closer to the average for us modern humans of 1350 cc.

Question 117

Erectus/ergaster cranial features

Answer 117

lateral view: * Brow ridge- juts out over eyes * Supratoral sulcus- channel like depression. * Cranial vault is long front to back and low up to down (arrows). * The back of the cranium jutted out in an angular ray called the occipital torus. * Receding chin, lacked prominent chin like ours. * Alveolar prognathism, not like a chimp, but different than ours * Similar teeth but slightly larger. * Frontal View Frontal view: supraorbital torus is continuous across the brow (like a shelf) * Sagittal Ridge. Light ridge running front to back in the center of the head. Different than paranthopenses and has nothing to do with chewing muscles. * Homo Erectus has a thicker brow ridge than Ergaster. * The cranium has a pentagonal shape in rear view; flat bottomed, inward sloping sides and 2 surfaces at the top. maximum width is near the base of the skull

Question 118

* Fossil 3733 Koobi Fora Kenya

Answer 118

* H. ergaster * 1.75 mya * 850 cc * When compared to A afrarensis and Hablis: Ergaster is increasing brain size and trends toward a flatter face- larger brow ridge in Ergaster

Question 119

* “Nariokotome Boy” or “Turkana Boy” West Turkana, Kenya

Answer 119

Ergaster * 1.65 Mya is when he died. * 85% complete skeleton of a young boy * Rare to have a complete skeleton survive this long. * Was 160 5’3” cm tall when he died. If Ergaster had grown at a similar rate to us, he would have been 12-14 years old. But teeth analysis showed that he was around 8, meaning he was really tall and Ergaster matured faster than modern humans. * If he grew up to be an adult he would have been over 180 cm tall, around 6 feet and weighed over 70 kg. * 880 cc- likely as large as it was going to get since hominin brains reach full adult size before age 10.

Question 120

* H. erectus fossils

Answer 120

* We have some fossils that date back to 1.6, 1.7 mya years ago but the below fossil is one of the oldest cranial ones. * Olduvai Gorge Hominin 9 dated to 1.2 mya * Discovered by Louis Leaky in 1960 * Just brain cage and brow ridge * 1000 cc- getting quite large, closer to us today we are 1350 cc * “Daka” cranium Ethiopia dated to 1.0 mya Afar Depression * 1100 cc * like the Olduvai Gorge fossil, it's very similar to the Asian home erectus fossils. * Typical Erectus brow ridge, thick and robust * Also has a double arch which is beginning to foreshadow homo erectus immediate descendent, homo heldelbregensis.

Question 121

Global reduction in forests .. when? what happened as a result?

Answer 121

* Starting 2.5 mya: * Global reduction in forests >> increase in open, grassland habitats in Africa and across the world. * Hominins forced to adapt to these open grassland conditions. * Hominins faced with loss of original forest habitat: need to adapt * Evolved large body with long legs >> more efficient bipeds, perhaps even modern running abilities. * Evolved effective thermoregulation system and hairless bodies * And an even larger brain * ALSO: * Grasslands have much larger quantities of animals (huge herds) highest animal biomass of any natural biome- support huge herds of species like wildebeests, more pretty to hunt and to eat. More than the forests. * Increased reliance on meat (more active hunting and/or better at it?) Relied less on scavenging and became active hunters, or became much better at active hunting 2 mya. * Probably part of a general broadening of the diet- a wider range of foods allowed them to live in a wider # of environments. * Classic example of adaptive radiation- move to a new environment, select for traits that allow survival in this environment. * Hominins spread out from Africa - following the spread of grasslands?- slow dispersion, spreading out to grassland ecosystem, no specific destination. * Became adapted to grasslands where game animals are abundant. * Millions of years ago there were huge lakes in Africa and thick tropical jungles, up to 5000 years ago these deserts were much smaller. * 3-3 mya, jungle started to be replaced by grassland and small deserts. * 2-1 Mya, savannah grasslands spread from west Africa to eastern China. * Supported huge herds for homeo ergaster to hunt. They followed the spread of grassland to Asia. This is the ecosystem they were now adapted to.

Question 122

* Dmanisi, Republic of Georgia-

Answer 122

oldest uncontroversial hominin site found outside of Africa. * Medieval castle and monastery * Been excavating since 1930’s * In the 80s they found an extinct rhinoceros, dating to over a million years ago at first thought was just a paleontological site. * Volcanic rock and ash dating to 1.8 mya * This site is the earliest evidence for hominins leaving after * So far more than 50 hominin bones have been recovered * 5 craniums * Hominis was about 5’3” and 160 cm tall. * Not as tall as Narikotome but taller than bhablis. * Then they found stone tools.

Question 123

* Dmanisi hominin fossils

Answer 123

* taller (up to 160 cm) and look like ergaster … * Mean cranial capacity = 650cc (very small!)similar to habils brain size. * Cranium #4: elderly man- best preserved, has cc of 550 cc- close to paranthepous boises and robust brain sizes. * No teeth- man survived without the ability to chew so was looked after by his group- eating mean but not cooking it yet.

Question 124

* These fossils change things: (Dmanisi )

Answer 124

* Primitive fossils meaning that this population fossils left Africa in the very early stage of Ergaster. * Mean stature drops a bit …but still taller than other early hominins. … but brain size drops from 850 to 750, … which means a smooth transition in brain size from small to large-bodied hominins up to Hom erectus. Now looks smooth from hablis to Ergaster and the big jump in brain size thought to occur at 2 mya isn’t really there. From addipiths to Ergaster it increases 100 cc for each genus. * Affects language and cooking hypothesis as the jump in brain size was said to happen * But maybe it was more like 5 mya that language and fire occurred?!? * This is the only evidence for Ergaster leaving Africa- we have other sites in Europe but no actual fossils just stone tools. * Likely the stuff in Europe is the 2nd migration and is primarily homo erectus. * Have evidence they arrived in asia 1.6 mya

Question 125

* Homo erectus in Asia

Answer 125

* Did not move north, no sites in Russia, likely as they wanted to be warm. * Spred around other sites of Asia. Sticking to grasslands

Question 126

* Homo erectus sites in China:

Answer 126

* Nihewan Basin *Larger river valley 150 km west of Beijing river cut down thru sediments, exposing sites on the valley sides.* Sites with stone tools and animal bones, but no hominin fossils – yet * Oldest is 1.6 mya – oldest in Asia so far * A few claims for older sites in China but not been confirmed yet. * Zhoukoudien (or Zhoukoudian or Choukoutien) David Black * Called a cave but actually a large chasm that has collected layers for many years. * Found partial remains of over 40 hominin individuals. * Davidson black names these Easter Mna from Peking. * Now considered to be Homo Erectus. * 800-700,000 years old bp mean cranial capacity = 1040 cc * Many fossils disappeared during WWII and never turned up again.

Question 127

* Homo erectus in SE Asia

Answer 127

* Solo River, Java * Late 1880 Eugene dubois arrived in the Dutch Indies to search for a missing link. * In 1884 dug up first erectus fossils found, later digging around the Solo River, found many more erectus remains. * 20 cranium have been found here, solo river. * Sangiran 17- one of the most complete * Most have typical erectus features, but Sangarin 17 is particularly robust. * Cranial capacity = 1030 cc * Dates for Homo erectus’ arrival in Java? * Been difficult, dates as early as 18. Mya as discussed in textbook * Modern dating was not available back in the 1800s when dubois guys were first working there.

Question 128

Biochronology

Answer 128

Biochronology is a method in paleontology and geology that involves the use of fossil assemblages or specific species' occurrences to establish the relative ages of rock layers or geological formations. This technique relies on the principle of biostratigraphy, where the presence or absence of certain fossils is used to correlate and date different rock layers.

Question 129

* “Daka” cranium Ethiopia

Answer 129

1.0 mya- 2 important features- 1- robust superorbital toros- thick brow ridge 2- distance double arch. H erectus

Question 130

* Bodo cranium, Ethiopia

Answer 130

dated to 600000 years ago. A good candidate for early heidelbrengesis fossil. Has a big brow ridge, cc of 1200 – closer to our 1350. * Also: has cut marks from stone tools below left eye socket- requires explaining. Cut marks on the hominin skull suggested to be evidence of cannibalism. OR could be from intentional scarification- common in recent African groups- creating scars in unique tribal patterns, OR defleshing of the skull after they died so the skull is kept

Question 131

* Kabwe or “Broken Hill” cranium, Zambia in south-central Africa

Answer 131

Heidelbregenis. Discovered in a mine shaft in the 1920s, recently been dated. * 300,000 bp- half the age of the Bodo cranium and getting close to when modern lineage is thought to have begun. * 1300 cc * Very large double-arched brow ridge and very large brain. Starting to look like us.

Question 132

Homo erectus lithic technology

Answer 132

* Mode 2: Acheulian Industry- (earliest stone tools – Oldowan industry is mode 1) * Acheulian appears around 1.5 mya- the appearance of handaxes. Appears shortly after Erectus, so assuming Erectus invented this. Eventually, they spread to Asia and Europe- not until 1 mya. Then- * 250 kya they disappear everywhere * Achulean handaxes are “bifaces” (2 faces) manufactured to create a thin symmetrical tool with a sharp cutting edge. Many shaped, most common teardrop * “mental template” individuals had a predetermined idea of what a hand axe should look like and used this to create the final shape of the tool. First time in prehistory with a specific tool type- not sure what used for, assuming all purposes like a Swiss army knife.

Question 133

* How did Homo erectus get from Mainland Asia to Java? 1.5 mya

Answer 133

* Java is an island, have to cross the water to get there. * 2 narrow channels, from the mainland to Sumatra then from Sumatra to jave * Did they build boats? Maybe * Much easier for erectus to get to Java- during the ice age- the lower sea level- dropped 50 m, and the Sunda shelf appeared which connects Sumatra and javal. Also sahul- Australian and New Guinea. * There were 6 different ice ages over this time. * During warm periods, java became an island and homo erectus was stuck there. * We modern humans reached Australia by 50-60 kya How did we get there? * Erectus did not make it to Australia, there is a deep part called the Wallace line- so couldn’t walk. * Humans to Australia: likely by boat. Modern humans are intellectually capable. Boats made from wood and animal hide would not survive so no direct evidence of these boats. Strong circumstantial evidence of simple boat technology. Found deep sea fish bones and hooks dating 25000 to 40000 years ago. To find deep-sea fish you need real good boats

Question 134

* Who is Homo floresiensis?

Answer 134

* Liang Bua Cave, Flores 2003 * Bones of 9 individuals were dug up. * Homo sapiens 1.6 meters tall 1350 cc * “Hobbit H. Floresiensis 1.1 meters tall! 450 cc Noticeable characteristic, they were small! * They are considered part of our genus but are a different species. * 2016 Hobbit find Mata Menge, Flores 700,000 bp over 10 times older than the original fossils. * Means they arrived here 700k years ago and lived there tilla t least 65k years ago. * Only a few bone fragments were found, and even smaller than the original bones from Bua Cave. * Hobbit’s place in the Hominin Phylogenetic Tree * 3 possibilities: decedents of an undetected migration of australopithecines but we don’t see these guys out of aftice. 2- decendents of early migration of homo hablis, but no evidence of hablis outside of Africa either. 3- descendants of erectus- near Java where erectus was 700k years ago. This would mean that some erectus made it across Wallace's line to Flores and then evolved to be much smaller. * * More water-crossing mysteries! How did they get to Flores? Erectus may have had simple rafts. * Hominins on Flores Island at 700 kya? * Jump Dispersals? Another potential explanation for folrensis. Accidental rafting. Tsunami waves- even modern day in 2004 with a big earthquake, ppl swept to sea rafters on debris to survive. * Why so small? Even short compared to australopithecenes who were 100 cm tall. *

Question 135

Island Dwarfism-

Answer 135

Island Dwarfism- evolutionary phenomenon. Common among animal species on small islands with no large predators. No pressure to have a larger body to defend and limited food sources on the island- many examples of this living and extinct. Stegadon florensis, a tiny species of elephant that lived on the same island as the hobbits. Seems like homo florensis hunters dtegadon florenesis. * Also dward rhinoceros.

Question 136

* Insular Gigantism-

Answer 136

another phenomenon. Result in larger than typical species, without major predators a small species can be larger, like the giant flores rat- 8 times heavier than the common rat today- hobbits hunted and ate these- and the giant rat is still alive today.

Question 137

* 3 homo migration events to Europe

Answer 137

* Not a lot of fossils, but likely similar to Homo Erectus in Asia. * 1/ some form of ‘H. rectus arrives by 1,400,000 bp * 2/ H. heidelbergensis arrives ≈ 600-500,000 bp * heidelbergensis evolves into Neandertals * 3/We modern humans arrive ≈ 45,000 bp

Question 138

* Barranco Leon

Answer 138

most important Hominin site. Open-air site- not a cave: * one hominin tooth o also simple Oldowan stone tools – similar to the oldest ones from East Africa. o 1.4 mya and dated by various methods: o small mammal Biochronology – changes in species of different small mammals through the different layers. o Paleomagnetism (more on this below) o oldest evidence for hominins in Europe discovered so far but with just a tooth it's not so exciting. Barranco León (Orce, Guadix Baza, Spain) is one of the sites with the oldest evidence of human activity in south-western Europe. This site has yielded human remains in association with both fauna and lithic artefacts, linked through the presence of anthropogenic cut and percussion marks

Question 139

o Atapuerca, Spain

Answer 139

o Atapuerca Hills, Spain- not very high, close to a city called Bergos. Has some of the oldest archaeological sites in Europe. o UNESCO World Heritage Site o The 19th-century rail line cut through several dolinas (vertical caves like in S. Africa) o Cave system and Dolinas formed several million years ago, but have been filled with rocks, stone tools and hominin remains

Question 140

o Sima del Elefante

Answer 140

o Atapuerca

Question 141

o Gran Dolina

Answer 141

Atapuerca 1981-1993 test excavation- beroe the railway was cut away there would have only been a large hole in the top, and things would fall in and add to the layers of sediments. Fragments of animal bones sticking out here and there. o Test: wanted to know which layers had stone tools, hominin remains, etc. o 2mx2m could be excavated quickly to get an idea of what was in there. Took only 12 years. o Mid-1990s formal excavations. Still digging. o 11 major layers or strata. Thick layers. o Gran Dolina: Layer 6- 100 hominin bones. Partial cranium, part of a mandible, and vertebra. 6 different individuals, this came from a 2 x 2 area of the test column, so I expected them to find way more. o This is the most complete cranium over 400000 years that we have from Europe. o Evidence of occupation even lower, no hominin bones but several stone tools.

Question 142

o Sima del Elefante

Answer 142

‘Pit of the Elephant’ is another huge Dolina- about 100 m away from the last. Work has only been going on here for 20 years, so very small area compared to Gran Dolina o 21 layers of accumulated sediment compared to gran dolinas 11. The lowest layers here are much older than gran dolina, and started filling up way before. o In 2008 layer 9 had a mandible- chin region and no teeth, and hand bone, just a single finger bone. olddowan tools o Sima del Elefante stratigraphy o Sima del Elefante Layer 9 o finger bone (phalanx) o Oldowan tools o Mandible fragment o modern human mandible o How old are the Gran Dolina and Sima del Elefante fossils??

Question 143

o Paleomagnetism

Answer 143

o Earth is surrounded by a magnetic field that protects us from radiation, created by Earth’s iron core. Positive end at the north pole, negative end at the north pole. It is not stable, it changes the angle at which it enters and exits the earth's surface. Regularly switches polarity. Normal like today, then reversed polarity, occurs in 10’s of thousands of years. Would only know by looking at a compass. o Normal Polarity o Reversed Polarity o History of Earth’s Paleomagnetism o Chrons: these reversals. o e.g., Jaramillo Subchron @ 1.0-1.1 mya (long arrow)- sub-chron- will be useful in a moment.

Question 144

what happened 780 kya fro, a paleomagnetism perspective?.

Answer 144

Matsuyama reversed to Brunhes normal he Matsuyama-Brunhes reversal, also known as the Brunhes-Matsuyama reversal, is a significant geomagnetic event that occurred approximately 780,000 years ago. This reversal refers to a switch in the Earth's magnetic field, where the normal magnetic polarity (as we observe today, with the magnetic north pole near the geographic north pole) temporarily became reversed. The reversal is named after two geomagnetic chrons: the Matuyama Chron, which represents the normal polarity period, and the Brunhes Chron, which represents the reversed polarity period.

Question 145

o how can we use paleomagnatism to-date sites?

Answer 145

o When sediments slowly accumulate: tiny iron particles orient to Earth’s magnetic field. All sediments have tiny magnetic particles. o The particles align with whichever pole (North or South) is positive at the time o When sediments become compacted, particle orientation becomes locked in o Sediments with particles oriented north could be relatively recent since that’s the current condition. Deposited any time within the last 780000 years. o Doesn’t help as they could be 750000 years old or 10000 years old. o But if it's reversed polarity, we know that it's at least 780000 years old. o Archeologists will take small samples from each layer and see how the particles are oriented. o However, sediments with particles oriented south HAVE to be at least 780,000 years old (because of the Matsuyama-Brunhes reversal) o Using Paleomagnetism to date the hominin remains

Question 146

dating sima de elephante and gran dolina

Answer 146

Paleomagnatism: o Looking at this we narrowed it down but knowing it was between the Jamilla subcrhon and Bruhnes normal, so its between 1 mya and 780000 years ago, helps narrow it down. o Layer 9 with the finger bone and mandible are several layers below. We can estimate its average is 1.25 million years old. Combined with other dating methods they divided this. o These items are the oldest remains in Europe so far but not much to go on.

Question 147

oldest remains in Europe so far

Answer 147

sima de elephante and gran dolina

Question 148

o H heidelbergensis technology

Answer 148

brought Acheulian handaxe technology with them from Africa – or it was re-invented in Europe. Possibly they were independently invented here, but it's likely they brought from Africa when they came. Acheulian is taken from the Sant school river in northern France where hand axes were found in the mid-1800s. This is where that name came from.

Question 149

H Heidelbergenis moved to Europe when?

Answer 149

first appeared in Africa but about 600k years ago moved to Europe. None in Asia

Question 150

o Mauer, Germany

Answer 150

o Single mandible discovered in 1907 in Germany near Heidelberg. * “type fossil” of H. heidelbergensis (fossil for which name was invented) * massive lower jaw with moderately-sized teeth – slightly larger than ours * ≈ 600,000 bp- discovered before good dating methods were available so this is an estimate.

Question 151

o Petralona, Greece

Answer 151

* cranial capacity = 1230 cc- most complete and largest cranium found. * 650–250,000 bp difficult to determine age accurately. Likely 300-400k years old. * Our mandible kinda fits their mandible. o Petralona, Greece (Europe) compares the skull to: o Kabwe and Zambia (sub-Saharan Africa) are incredibly similar.

Question 152

Sima de los Huesos , Atapuerca

Answer 152

3rd example of homo heidlebregenis s fossils. Huesos (Means pit of the bones in Spanish) o Discovered in 1983. Hard to access, long dark winding walk. o ≈450,000 bp- stuff has been accumulating for hundreds of thousands of years. This is the layer of sediments with hominin remains. o Sima de los Huesos Hominin Fossils 17 crania and 7000 other bones and bone fragments. Also find animal bones, cave bears but also hominin bones. o Largest collection of early hominin remains of any site. o Likely did not end up here at the same time, but they are all members of the same population. o Bones are disarticulated and spread out. Hard to match up and put individual skeletons back together like they tried to do with the Australopithecus from the Malapa in South Africa. But with such a bug collection we can do a lot more types of analysis than we can with a complete skeleton, like the Nakatomi boy from Turkana * MNI for the Sima collection is 28. Could be more. * at least 12 females and 8 males * determine the age when individuals die- especially using teeth. * One individual < 5 years old, 3 over the age of 35 but most were young adults. o Plesiomorphic features- rearview- pentagonal shape like homo erectus. o double-arched brow ridge- like homo erectus, like the 1 mya old Daka cranium from Ethiopia. o Pentagonal-shaped cranium ?? o Cranial capacity: 1025 to 1400cc o similar stature to modern humans: a large collection of leg and arm bones showing their stature similar to us. * males averaged 170 cm (5’8”) * females averaged 160 cm (5’4”) o At least 1 male was 180cm tall (5’11”) and weighed 90kg (200 lbs) o But … were much more robust and muscular o Any evidence of injuries? o Some bones had pre-mortem fractures – these occurred sometime before death and had time to heal. o But some skulls had new (unhealed) fractures- fresh impact fractures- likely occurred at or around the time of death, and could have been cause of death. Or could have been that the skull hit a rock when dropped into the pit after death. o Causes? o Violence? Normal product Or of cave life- rocks falling and hitting people?

Question 153

Sima de los Huesos , Atapuerca.. how did the remains get there?

Answer 153

o Living in the cave? Not likely: * poor access- need to rappel down with a rope to get in. , deep and cold, with sloped floor – not very uncomfortable almost no stone tools * Animal remains not typical of people food- none of this is left there. Only 1 stone tool was found and animal remains were not found from species of animals that people would have eaten, mostly cave bears and cave lions. o Dragged there by cave bears or cave lions? Could have been the meal for those carnivores. o Maybe: * There are carnivore gnaw marks on some bones o But! o Not typical of carnivore meals! The age profile of hominin remains does not match typical collections of carnivore prey- usually very young or very old. Even large predators do not go after prime-aged adults. This is the opposite, so likely not the carnivores that brought them to the pit, also how did the carnivores navigate the pit? o Intentionally thrown in? o If so, why? o Was it a funeral ritual? Disposing of remains of the dead would have been a lot of effort to carry them through the cave system- most researchers think it was this and that it was a ritual. The only stone tool found- a hand axe- was a ritual grave good thrown in. But the skeletons did not enter the pit as whole bodies, they did not stay together and would have if they were thrown in whole. Need to rule out simple explanations: o Just washed through the cave system into the pit? From some other location in the save system, perhaps higher up in the system where the hominin could access. o Water regularly goes through cave systems, it's how they form. Sima is like the sediment trap in the sink where things get trapped. A common process in caves like this.

Question 154

Modern Human Variability Part 1: Historical views: “Race”

Answer 154

We are 99.9% the same but there is obviously some differences between us, physical features and things like blood type and obesity etc. that you cant see. Common view that we can be determinedby race.

Question 155

C. Linnaeus (mid-1700s) perhaps the first to try to classify modern humans systematically in 4 groups:

Answer 155

Homo sapiens Europeus albescens :white people from Europe Homo sapiens Africanus negreus :black people from Africa Homo sapiens Asiaticus fucus :dark people from Asia Homo sapiens Americanus rubescens :red people from the America

Question 156

Anders Retzius (1840s) developed the Cephalic Index

Answer 156

Used to put people into discrete groups Cephalic Index = breadth/lengthx100 ≤ 75 = dolicocephalic 75-79.9 = mesocephalic 80-84.9 = brachycephalic 85+ = hyperbrachycephalic Simple cranial metrics were taken to reflect differences in cognitive abilities and personality traits

Question 157

Alfred Kroeber’s “Family Tree of the Human Races”

Answer 157

Saw early modern human fossils of having distinct racial features and assigned them to groups on that tree. Carleton Coon 1960s-1980s categorization of human races: * Caucasoid ‘white’ * Mongoloid ‘Asian’ * Australoid ‘Australasians’ * Negroid ‘Africans’ * Capoid ‘Bushmen’ of S Africa The idea of intrinsic differences between ‘races’ was a product of the notion of Social Evolution: … the idea that cultures evolve like organisms and that this results in ‘more advanced’ forms. Today we know that even biological evolution is not directional. Different advances are from different circumstances.

Question 158

biological Determinism.

Answer 158

Cultural variability was seen as biologically determined and, therefore, inherited in the same way that physical characteristic like skin colour and shape of the head s were. Dominated western thought into the 1900s The idea that people of different geographic origin have biologically determined differences – that some are superior to others - is the definition of racism. This belief in superior and inferior groups and individuals among humans led to eugenics movements in most countries, including Canada and the USA. Looking to do selective breeding to control the quality of the future generation. But most traits are polygenic, and intelligence is complicated and strongly affected by the environmental. Cant improve the IQW of a population by breeding smart people only.

Question 159

Race and Intelligence?

Answer 159

The most damaging misconception that has accompanied the assertion that humans can be divided up into visibly discrete groups is that they are inherently different in complex human characteristics like cognitive abilities ... There is no evidence that complex characteristics like intelligence vary with skin colour or geographic origin. Influenced by many different factors. This view has disappeared and vastly rejected.

Question 160

The Concept of “Race” Today?

Answer 160

Mostly used to determine people from different cultural backgrounds . The most common and prevalent use is still based mainly on perceived geographic phenotypes: “Race” = visibly distinct groups associated with broad geographic regions.

Question 161

For most people this seems to be real, that people can be divided into races based on skin colour. But there are 3 problems.

Answer 161

1. There is a very low degree of genetic variability among modern humans, making it unrealistic to try to break us up into discrete categories. 2. If you try to group us based on individual traits (eg skin colour) you discover its impossible to create distinct groups. 3. If you compare the genetic makeup of people from different groups you will find that there is more variability between people in the same group than between other groups. 1/On average, we humans differ from each other in 0.1% of our genome: we are 99.9% identical to each other Each branch is a unique population, and the length of the branch represents how different they are from what they diverged from. Chimps differ a lot from each other at 1.2 %! Modern human groups have never been truly isolated and continue to interbreed with each other. /

Question 162

The Problem with ‘race’ and the Normative View

Answer 162

The normative view = members of different groups are characterized by discrete traits and so can be easily divided into discrete groups/categories. Based more on opinion than fact. English people like tea have bad teeth and have a good sense of humor, bad cook. French are wine drinkers good cooks, good fashion sense… But obviously, there are English that drink wine. Does that make them French? Obvi not. Studying different people around the world, anthropologists were seeing continuous (not discrete) distributions of traits across “racial” boundaries and between geographic regions. Continuous in their form and have no boundaries between populations. All the traits we can see (and those that are not visible, like blood type) have a clinal distribution – they grade across geographic space in either frequency or form. Blood type A increases or decreases across populations. Skin Colour Distribution You could never find a place that creates a discrete difference. Humans are a recently evolved species, and genetic diversity is very low compared to other great apes

Question 163

DNA and Race

Answer 163

Furthermore, of the minor genetic differences between us, there is more difference within any one geographic population than there is between different populations. Individuals with a common geographic ancestry will share some characteristics that may visibly distinguish them from individuals from other geographic regions (eye colour, head shape) ... ... but, in fact, they typically have more genetic differences between them than either one has with individuals from distant geographic regions (blood type, eye colour, hair type, etc. etc.). Species variation is mostly between populations Species Variation is mostly within individual populations Human genetic diversity is distributed mainly within populations We have not been genetically isolated from each other for any large amount of time so that is why there is less genetic variability between human populations

Question 164

If you choose one characteristic to group people by

Answer 164

messes up all the other features and there will be so much variability. There is no way to organize people that makes sense. For example if you organize by skin colour, the blood types will be different. degree of variability Currently, there is no genetic basis in support of the concept of race.

Question 165

Human Biocultural Evolution

Answer 165

Among all organisms other than humans, evolution occurs strictly at the biological level. Humans also use culture (which includes technology) to adapt to changing conditions. Technologies allow us to modify our environment to suit our physiological needs. Culture is often defined as an extra somatic(body) means of adaptation. Means adaptation byond our biology. Modifications to our environment have brought about conditions to which we have had to adapt physiologically: now that we use tools our evolution is cultural and biological. Some things we had to do to adapt: Slash and burn agriculture and malaria. We do deforestation to plant agricultural crops, resulting in more mosquitoes. It's regions like this that sickle cell anemia is selected for. The change from being mobile hunter-gatherers … … to farming and living in sedentary societies. This change drastically changed our lives. Larger groups meant living in closer contact to more people. So we had to adapt physiologically. We are still hunter gatherers in many ways and are still adapting to this.

Question 166

Lactose Intolerance

Answer 166

Humans typically lose the ability to digest milk (lactose) after adolescence. Resembles pattern of babies being weaned and eating normal food. However, several societies have developed the ability to continue digesting lactose into adulthood—different populations in Asia and Africa. Sheep, goats, and cows were domesticated 12k years ago with milk being used and changes in the ability to have milk.

Question 167

Evolution vs. Acclimatization

Answer 167

1. Very short-term response to environmental change: * perspiration and vasodilation when exposed to heat and vasoconstriction (goosebumps) when exposed to cold . open or close pores depending on tem. * eyes adjusting to the dark 2. Short-term adaptive changes: * increased melanin production when exposed to increased ultraviolet (UV) light. tanning. * increased hemoglobin production and lung capacity from living at high altitudes. Allow increased absorption of oxygen in the blood in low oxygen conditions. When they move, it goes away. Such adaptation is still only temporary: acclimatization. 3. In the long term, humans do undergo major physiological changes in response to changes in environmental conditions - evolution: * darker skin in environments with high UV exposure * Which likely followed the loss of body hair coverage … * following evolution of an efficient thermoregulation system … * following the move into hot, open grasslands… * … we think * shorter, squatter bodies in colder environments to improve body heat retention:

Question 169

East Africa- less caves *

Answer 169

Rivers and lakes -Rift Valley. * 6000k long fault. Lots of sediments have been settling in the fault. * Rivers come here and expose fossils. * Ekembo and hominin species dating to 5 million yeas ago found here