FINAL EXAM: TUESDAY DEC 21 ST GYM 9-11AM
CHAPTER 10: EVOLUTION AND NATURE OF MODERN HUMANITY
The major models in an ongoing debate
Modern looking people first appeared 195 000 to 165 000 ya; showing modern traits as far back as
300 000ya (triats first appeared in Africa)
Two major models for the origin of our species:
1. Multiregional Evolution (MRE) model: single-species model; the hypothesis that h. Sapiens
is about 2 myrs old and that modern human traits evolved in geographically diverse locations
and then spread through the species
Claims that h. Sapiens rose in Africa about 2 mya; when we see anatomical and
behavioural characteristics that define out type of primate). Members of this
species (h. Erectus) spread throughout the Old World, evolving genetic and
phenotypic regional difference. Degree of species mobility resulted in sufficient
gene flow to maintain a single species resulting in no speciation. Successful
adaptive features were dispersed across the species through gene flow. Premodern
species are members of our species.
Homo sapiens were not a separate species, they did not rise in the recent past, and
that it did not spread and replace other species of homo.
If this model is correct then there should be no evidence that modern h. Sapiens
is a separate species from premodern groups. That is there should be no traits that
is found among all populations classified as modern that is lacking among all
premodern populations. There should be some evidence of interbreeding. There
should be regional continuity of traits – features of geographic areas that appear
in modern and premodern populations.
• No biological meaningful definition of modernity
• Populations with transitional sets of traits be found in many locations
• Regional continuity of traits
2. Out of Africa model aka Recent African Origin (RAO): hypothesis that h. Sapiens evolved
recently as a separate species in Africa and then spread to replace more archaic populations.
View that modern h. Sapiens as separate species that branched from a pre-
existing archaic homo species in Africa around 200 000 to 150 000 ya. These
species then spread over the Old World replacing archaic populations.
If this model is correct then there must be a clear distinguishing feature between
modern species and premodern (archaic) humans. There must be traits that all
homo sapiens share that are not found in premoderns and vice versa. There
should be genetic distinction.
• Anatomical definition to distinguish modern from premodern
• Genetic distinctions
• Transitional forms appearl only in a single region in which modern
1. Fossil Record:
Trasitional forms between archaic species (h. Heidelbergensis and H. Neadrathalensis) and H
Sapiens are only found in Africa.
Fossil record of homo does not show division into separate species. That, H sapiens and H.
Erectus are hte same species. Modern traits did not all arise in one location but in many and
spread throughout the speices through gene flow to be expressed differnelty in different
geographic locations. Supports MRE model – that trasitional forms are found in many locatio
Neandrathals’ large continous brow ridges are a major feature distinguishing them from mo
humans. Indigenous people in austrailia (fully modern people) have large continous brow rid
Wolpoff and colleagues found similarities and differences of skuls from both modern and arc
from different parts of Europe, Africa, asia; this pointed to a mixed ancestry of the modern
population. Also evidence for MRE.
2. Cultural Evidence:
o Early modern human sites in Africa show more sophisticated technology than
contemporary tool assemblages in Europe and asia associated with premodern humans.
o World oldest blade tools discovered in Kenya, recovered near Lake Baringo and dated
about 240 000ya. Makers of this tool careful prepared the stone cores from which they
were struck to ensure the tools’ precision and consistency. This kind of preparation
involves high level of abstraction and planning; an intellectual advance of hominids in
o At Klasies River Mouth (south Africa), there are long, bifacially worked spera points
made on stone blades detached from cores = a punch technique. Long blades are removed
from stone cores by striking a punch made out of antler with a hamerstone. Longer,
narrower, thinner flakes. Occurs much later in Europe
o Ketanda, Democratic Republic of Congo show more evidence for toolmaking in Africa.
Dated 90 000 ya. This sites have produced bone tools – barbed, harpoonlife pericing
tools. Premodern homo sapiens are not known to have produced anything like this.
b) Out of Africa:
o Stone tool assemblage of the earlier neandertals of Europe and southwest asia simply do
not look very different from the toolkits (group of tools used together to perform a
particular task) of the early moderns of Africa and SW Asia.
o Aurignacian: toolmaking tradition of anatomically modern homo sapiens of the
European Upper Paleolithic.
o There are evidence of replacement: older Mousterian industry associated with European
Neanderthals and later industry (Chatelperronian = stone tool industry associated with
www.notesolution.com late neaderthals in Europe; are long sharpened blades). Chatelperronian represents a more
efficient use of stone. The Chatelperronian posseses more sophisticated tools than the
Mousterian but the aurignacian is more sophisticated than the Chatelperronian. It is
assumed that Mousterian neandertals in Europe developed more advanced
Chatelperronian after coming into contact with and borrowing some ideas from
aurignacian modern humans who had entered Europe from SW Asia. They shared
technology and perhaps even interbred. With this being said, modern toolkit is slightly
better providing modern humans an advantage.
3. Genetic Evidence:
Genetics have been interpreted to support the RAO model.
Chimp DNA exhibits 10 times the amount of variation as does human DNA. This suggests a
recent common source for all living things – consistent with RAO model
(little genetic diversity = not much time elapsed since the species first evolved).
Our species genetic homogeneity does not help us dintinguish btwn the two models.
Nuclear DNA may provide for a more accurate record of the genetic history of 2/more divergent
Mitochondrial DNA accumulates mutations and is inherited from female line.
DNA on Y chromosome allows us to trace inheritance through on parental line.
Studies concluded that 1. the word’s peoples tend to cluster into 2 genetic groups- those fro
Saharan African and rest of the world. 2. Africa is more genetically diverse than the rest of t
world. Supports the ROA model.
o There was more gene flow within Africa and within the rest of population than betwee
Africa and the rest of the world = contributes to genetic distinction.
When compared the gene sequence in modern humans and neandertals, there were more t
times the number of differences between the neandertal and the moderns than btwn any tw
groups of moderns. These samples (obtained from old bones of neadertals) showed no spec
similarity to modern Europeans, being equally distinct from all modern pop. Neadertals mad
contribution to modern mtDNA and that our two lines diverged 690 000 t