For exam, lecture 3 Flashcards

1
Q

when did the Pleistocene Epoch last

A

from between 1.8 mya- 12 kya

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2
Q

what are the divisions of the Pleistocene Epoch

A

lower
middle
upper

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3
Q

how long did the lower Pleistocene last

A

1.8 mya - 780 kya

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4
Q

what is the lower Pleistocene characterized by

A

steadily decreasing global temperatures

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5
Q

when the did middle Pleistocene happen

A

780 cya - 126 kya

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6
Q

what is the middle Pleistocene characterized by

A

generally low, yet wildly fluctuating temperatures

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7
Q

when did the upper Pleistocene happen

A

126 cya - 12 kya

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8
Q

what is the upper Pleistocene characterized by

A

corresponding to the end of the last major ice age

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9
Q

Earth’s glacial and interglacial periods within the Late Pleistocene have been caused primarily by what

A

cyclical changes in the Earth’s circumnavigation of the Sun

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10
Q

what do the cyclical changes affect

A

These changes affect the seasonality and location of solar energy around the Earth, thus impacting contrasts between the seasons

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11
Q

what are the 3 changes of the cyclical changes

A

eccentricity
obliquity/ Axial Tilt
precission

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12
Q

what are the cyclical cycles called

A

milankovich cycles

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13
Q

what is Eccentricity

A

changes to the shape of the Earth’s orbit around the Sun. Orbital shape ranges between more and less elliptical on a cycle of about 100,000 years. Greater variation in Sun’s energy reaching Earth when orbital shape is more elliptical

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14
Q

what are we currently in (which cycle)

A

in between the stages of eccentricity AND axil tilt

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15
Q

what is Axial Tilt

A

is the inclination of the Earth’s axis in relation to its plane of orbit around the Sun. Oscillations in the degree of Earth’s axial tilt occur on a periodicity of 41,000 years from 21.5 to 24.5 degrees. Affects the severity of the Earth’s seasons

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16
Q

what is Precession

A

is the Earth’s slow wobble as it spins on axis. This wobble has a periodicity of 23,000 years. Contributes to differences in seasons felt by the Northern and Southern hemispheres

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17
Q

are H. erectus and H. ergaster the same or different

A

Until fairly recently, all specimens today classified as H. erectus or H. ergaster were considered a single species: H. erectus (“upright man”); those from outside of Africa still are

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18
Q

what led many paleoanthropologists to classify these as members of a separate species(dragster and erectus)

A

However, some marked morphological differences in the specimens from East and southern Africa have led many paleoanthropologists to classify these as members of a separate species

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19
Q

what does H. ergaster mean

A

working man

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20
Q

intros course do we consider eraser and erects the same or different

A

different
In this course, we will consider these two variants to be separate species; however, the groups are morphologically, behaviorally and (likely) culturally very similar to one another, and share a clear ancestral relationship

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21
Q

what is the main difference between erectus and ergaster

A

Although both H. erectus and H. ergaster appear at around the same time in both Africa and Asia (ca. 1.8 mya), the scholarly assumption is that the origin is Africa, as it’s the only place with a likely bipedal ancestor— H. habilis. However, the closeness of dates poses a problem…

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22
Q

What are the Homo ergaster Early Dates (E. and S. Africa)

A

The earliest confirmed dates for H. ergaster coalesce around 1.8 mya.
Fossil specimens come from several sites in Kenya, Ethiopia, Tanzania and Swartkrans, South Africa

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23
Q

The finds in Kenya indicate H. ergaster and H. habilis may have overlapped by around how many years

A

500,000 years

24
Q

The early H. ergaster fossils are occasionally associated with what

A

Oldowan tools

25
Q

what are the Homo erectus Early Dates (Europe / Asia)

A

H. erectus georgicus appears at the crossroads of Europe and Asia (Dmanisi, modern–day Republic of Georgia) 1.78 mya

26
Q

what is the cc of the Dmanisi fossils compare to the other H. erectus / ergaster

A

brains that were unusually small (~600 cc) compared to all other H. erectus / ergaster individuals (between ~850 –1100 cc).

27
Q

what is the problem of Homo erectus / ergaster Origins

A

The problem is one of distance and time. The Dmanisi and Javan H. erectus specimens don’t differ significantly either morphologically (as we’ll see) or temporally from the earliest H. ergaster specimens in Africa. Thus, the presumed emigration of H. ergaster out of Africa could only have occurred if…
1. A few or all of the acquired dates are wrong;
2. The expansion out of Africa was a very rapid one;
3. The expansion out of Africa occurred earlier than 1.8 mya and involved H. habilis (!)
None of these scenarios is particularly convincing, and at this point, we simply don’t know the answer.

28
Q

what is the Cranial Morphology of Homo erectus / ergaster

A

High vault elevation above orbits.
Relatively low post-orbital constriction.
Increasingly robust supraorbital toris
Longitudinal elongation of the skull
Decreased facial prognathism.
Reduction in molar/premolar size and thickness.
cranial capacity between 850 and 1100 cc

29
Q

what is the Post-Cranial Morphology of Homo erectus / ergaster

A

Postcranial bones of all known H. erectus and H. ergaster individuals show modern H. sapiens body proportions.
Body size was significantly greater than that of H. habilis / H. rudolfensis and generally similar to modern humans (avg. height of between 4’ 9” to 6’ 1”; avg. weight of between 88 and 150 lbs)

30
Q

the 1.5-million-year-old footprints discovered in 2009 at Ileret, Kenya (nearby to Koobi Fora) are likely attributable to what

A

H. ergaster

The prints show distinctly modern human-like foot anatomy – markedly different from that of the Laetoli footprint-makers.The stride was also similar to that of modern humans

31
Q

is there sexual dimorphism among H. erectus/ergaster

A

there is still a strong degree of sexual dimorphism among H. erectus/ergaster; males are approximately 25% larger than females.
However, the degree of dimorphism in erectus/ergaster was still ~30% less than that of earlier hominins, such as paranthropines

32
Q

what are the Homo erectus / ergaster Morphological Differences

A

Variation between only two key physical traits separate the two species:
Slightly more robust supraorbital tori in H. erectus.
Cranial bones are thinner in H. ergaster
Lack of a prominent occipital bun in H. ergaster

The size-related (e.g., H. erectus georgicus) and other morphological differences (e.g., H. ergaster) we have discussed are defined largely by geography, and are evidence that there was—at some point— genetic isolation among H. erectus / ergaster groups. This raises an interesting question: just how much gene flow, if any, was there among these groups?

33
Q

what may the differences between Homo erectus / ergaster be attributable to

A

These differences may be attributable to environmental / social variation, making H. ergaster simply an earlier / geographically distinct variant (or subspecies) of H. erectus. 
This would lead us to categorise H. erectus as a polytypic species (containing more than one taxonomic rank below)

34
Q

‘Lumpers,’ advocating that the various H. erectus/ergaster groups represent a single polytypic species (H. erectus), argue what

A

that genetic drift, natural selection and some gene flow among the various H. erectus groups on earth resulted in the morphological differences we see in the fossil record

35
Q

what do splitters argue about H. erectus / ergaster

A

Splitters’ argue that these difference can be explained through the various groups’ genetic/reproductive isolation (e.g., a founder’s effect), which resulted in distinct subgroups with little-to-no significant gene flow among them

36
Q

We know that anatomically modern humans evolved from H. erectus / ergaster.
If the ‘splitter’ position is true, it means what

A

that speciation events in one area would not be reflected in another; importantly, it also means our modern human ancestors could only have developed in one of three known areas (Europe/Asia, E. Africa or E./SE Asia)

37
Q

Between 1.8 and 1.6 mya, H. ergaster was utilizing what technology

A

Oldowan technology

38
Q

what was the diet of . ergaster

A

They were likely foraging and scavenging, much like H. habilis.

39
Q

when did Acheulean Tradition happen

A

Around 1.6 mya, a new tool tradition begins in Africa. Known as the Acheulean Tradition

40
Q

what is Acheulean Tradition characterized by

A

it’s characterized by pear- or teardrop-shaped handaxes. This becomes the dominant form of technology until around 600 kya—making it the longest-lasting tool technique ever utilized

41
Q

when does Acheulean technology reach europe

A

In SE and E. Asia, the Oldowan-style Chopper Chopping-Tool industry thrives, while Acheulean technology doesn’t reach Europe until between 500 and 800 kya

42
Q

The first uncontested examples of hearths (fire‐pits) for any hominin are found where

A

at Gesher Benot Ya’aqov, Israel

43
Q

When do the fire pits date to

A

dating to between 690 and 790 kya, where numerous hearths were found.

44
Q

where is there contested evidence of use of fire

A

There is, however, contested evidence of use of fire (possibly naturally-produced) by between 1.4 and 1.6 mya (Lower Pleistocene) at two sites in E. Africa

45
Q

what proof of fire was found At Chesowanja, Kenya

A

51 very small, concentrated flecks of reddish-‐brown clay, fired at 400° C.

46
Q

what species is argued to have used fire first and what evidence is there

A

At Chesowanja, Kenya, 51 very small, concentrated flecks of reddish-‐brown clay, fired at 400° C. The fragments were were found approximately 15 m from several P. boisei cranial vault fragments and fragmented non-hominin animal bones. Despite this, the researchers argue that H. ergaster was responsible for the fire and animal bone deposits

47
Q

what could be another explanation for the fire

A

Skeptics argue the concentration of these clay fragments appear to be consistent with a tree stump, burned out by a naturally-occurring brush fire

48
Q

what evidence of fire was found At Koobi Fora

A

discolored soil patches with Oldowan tools were once exposed to temperatures of between 200 and 400° C. It is unclear whether or not this was the result of natural fires. These patches were dated to between 1.5 and 1.6 mya

49
Q

where was H. erectus pekinensis found

A

Fossil remains of at least 15 individuals, later designated H. erectus pekinensis (“Peking Man”) were recovered from the site of Zhoukoudian, northern China, in 1921 by Canadian paleoanthropologist Davidson Black

50
Q

when does . erectus pekinensis date back to

A

The specimens date to between 650 and 780 kya (the end of the Lower Pleistocene).

51
Q

when might have H. erectus pekinensis used fire

A

770 kya?

52
Q

what evidence and doubt is there of H. erectus pekinensis using fire

A

Apparent ash layers within the Zhoukoudian cave site may indicate in-situ control of fire. Further, very small, charred animal bone fragments were found within these deposits, indicating cave occupants were cooking.
At this time, northern China would have been very cold, so heating would also have been important, however, much of the material from early excavations was lost during WWII, and evidence remains in doubt

53
Q

what evidence is there of H. Ergaster and fire and cooking

A

At the very large Wonderwerk Cave site in Northern Cape Province, South Africa, burned bits of animal bone and vegetation (as ash) have been recovered from sediments dating (not very securely) to around 1 mya. These deposits were approximately 30 m from the mouth of the cave, meaning they were likely not carried in by the elements

54
Q

why cook

A

Cooking meat kills bacteria and parasites, and it detoxifies some vegetables, essentially rendering them edible.
It takes far less energy to digest cooked food than raw food. This likely freed up more energy for the ever-developing brains of our H. erectus ancestors

55
Q

Cooking food correlates with biological changes what

A

H. erectus / ergaster

56
Q

how does Cooking food correlates with biological changes H. erectus / ergaster

A

Faster calorie absorption from cooked food results in species-wide growth spurt (increased body size)
Cooked food requires less digestion, so a narrowing in the ribcage and reduction of the intestinal tract
Reduced need for musculature related to chewing, so decreased importance and size of temporal muscles