Exam review, H. ergaster/erectus Distribution

Question 1

what is an example of lumper.splitter perspective in homo

Answer 1

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!
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: H. ergaster (“working man”).

H. ergaster (in Africa) and H. erectus (elsewhere)

Question 2

The earliest confirmed dates for H. ergaster coalesce around when

Answer 2

1.8 mya

Question 3

Fossil specimens of H. ergaster come from several sites where

Answer 3

Kenya, Ethiopia, Tanzania and Swartkrans, South Africa

Question 4

when did H. erectus georgicus live

Answer 4

1.78 mya

Question 5

where was H. erectus georgicus found

Answer 5

Dmanisi, modern–day Republic of Georgia

Question 6

The Dmanisi fossils possessed brains that were…

Answer 6

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

Question 7

the presumed emigration of H. ergaster out of Africa could only have occurred if…

Answer 7

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.

Question 8

H. erectus erectus was found where

Answer 8

In E. Java, Indonesia, H. erectus erectus (the famous “Java Man”), from Trinil, dates to around and 1 mya; another E. Javan H. erectus fossil (the “Mojokerto” specimen) has now been reliably dated to around 1.4 mya

Question 9

when did H. erectus erectus live

Answer 9

1.4 mya

Question 10

what are the notable cranial morphologies of Homo erectus / ergaster

Answer 10

Increasingly robust supraorbital toris

cranial capacity between 850 and 1100 cc

Question 11

what are the notable post cranial morphologies of Homo erectus / ergaster

Answer 11

modern H. sapiens body proportions.
Body size was significantly greater than that of H. habilis / H. rudolfensis
modern human-like foot anatomy
stride was also similar to that of modern humans.

Question 12

Homo erectus / ergaster Morphological Differences

Answer 12

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.
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)
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?

Question 13

what is the lumper perspective on Homo erectus / ergaster

Answer 13

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

Question 14

what is the splitter perspective on Homo erectus / ergaster

Answer 14

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

Question 15

when did Acheulean Tradition come about

Answer 15

1.6 mya

Question 16

what were Acheulean tools

Answer 16

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.
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.