FINAL EXAM: TUESDAY DEC 21ST 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
•Transitional forms appearl only in a single region in which modern