Chapter 10 Flashcards
Omo Kibish
- Excavation site in Ethiopia
- Discovery of earliest homo sapien fossils
- 195,000 ya
- Some fossils had more archaic features, others were more modern in appearance (population variability)
Jebel Irhoud
- H. Sapien site in Morocco
- 160,000 ya
- Individuals had some archaic features
- Shows that modern skeletal form is African (suppots MD)
Herto
- H. Sapien site in Ethiopia
- 160,000 ya
- Modern shape of cranium
- Still had some robust/archaic features
- Shows that modern skeletal form is African (supports MD)
Skhul cave & Qafzeh Cave
- H. Sapien site in the Middle East (Isreal)
- 115,000 to 90,000 ya
- Modern shape of cranium
- Rugged but not as archaic as H. Sapien fossils before 160,000 ya
Multi-Regional Model (MR)
Model assumes that H. Sapiens is an old species (1.7 mya=>Out of Africa1 ) and all populations of archaic humans tranisitioned to modern forms due to conistent gene flow and similar adaptive trajectories
- Assumes populations were in constant contact (more or less)
- Argues fossils due show widespread evolution into H. Sapien (features show continuity through time)
- Advocates believe all Homo species beginning 2 mya should be considered H. Sapiens
Recent African Origin Model
Model assumes that modern humans appeared as the result of a recent speciation event in Africa and subsequently dispersed throughout the rest of the world, replacing or assimilating all archaic human popuations
- Assumes hominins lived in small isolated populations
- Argues fossils do not show a widespread evolution into H. Sapien
mtDNA from modern living humans shows:
- More variation (mutations) in African compared to non-African populations
- Modern humans originated in Africa
- Supports RAO model
mtDNA from Neandertals shows:
- Average of 35 mtDNA differences (mutations) with modern humans and contemporary humans
- Average # of differences b/w humans is 11
- Neandertals are a separate species
- Supports RAO model
Ancient Nuclear DNA (aDNA)
-DNA isolated from ancient specimens
Significance: Researchers compared DNA of Neandertals to DNA of modern humans
-Showed Neandertals interbred with modern humans
-More genetic variants with living modern humans in Eurasia than Sub-Saharan Africa
-Provided support for MR model
Neandertal Y-Chromosome
- Doesn’t exist in humans
- Suggests that LCA b/w humans and neandertals was 588,000 ya
- Some genes cause miscarriages suggesting incompatibilaty (with humans) and seperate lineage
Denisovans
- Extinct species of human in genus homo
- LCA b/w humans and Neandertals was 1 mya
- aDNA shows Denisovans interbred with the ancestors of of modern Melanesians and Australian laborigines
- Contributed HLA alleles to modern humans, which are important to our immune system
Multiple Disperal Model (MD)
Model assumes three major disperals of human poulations from Africa in the last 1.7 million years: H. Erectus, H. Heidelbergensis, H. Sapien
- Combines features of MR and RAO
- Incorporates gene flow, population isolation (bottleneck effect) , and African origin of modern humans
- Small amount of variation in mtDNA suggests bottleneck effect at the time of origin in modern humans (Sahara Desert)
Human Leukocyte Antigen (HLA) System
Part of the human immune system that helps signal the presence of foreign substances in the body
- most polymorphic human genetic system
- some variants associated with particular diseases
Lavallois Technique
Type of stone tool production that supplanted the Acheulean tool kit and provided a higher quality tool that could be refined for a wide variety of uses
- Beginning 250,000 ya
- flakes, points, and blades
- As well as scrapers, notches, and denticulates
- Special way to prepare core
Out of Africa 2a
The movement of anatomically or skeletally modern humans out of africa
-Expansion of early forms of modern humans