ANTH 120 1st Edition Lecture 25 Outline of Last Lecture I. Neanderthal Behavior and CultureOutline of Current Lecture II. Modern Human OriginsCurrent LectureModern Human Origins Debate | 2 Models1. Multiregional Continuity a. Milford Wolpoff et al., 1994, 2001b. Local populations of H. erectus/ archaic in Europe, Asia and Africa continued regionally evolving onto modern humansc. Earliest H. sapiens did NOT emerge exclusively in Africa but in each region of old worldd. Gene flow prevented speciatione. Predictions:i. Continuity in geographic regionsii. Variation between populations is highiii. Significant admixture between populations (gene flow)iv. Neanderthals share more genes with Europeans than other populationsv. AMHS, Neanderthals, Archaics and H. erectus are the SAME species… H. sapiens2. Replacement Models (Recent African Origins)a. Humans originate in Africa, replace all other populationsb. AMHS originate in Africac. Replace all other populationsd. Complete Replacemente. Partial Replacement (Assimilation)f. Chris Stringer and Gunter Brauer3. Complete Replacement Modela. H: Modern populations arose in Africa ~200,000ya, migrated, replacing populations in Europe and Asia i. Predictions:1. Abrupt change of archaic populations to AMHS2. Minimal admixture between moderns and archaic (e.g. H. neanderthalensis)3. Neanderthals equally related to all contemporary human populationsb. No transition to modern H. sapiens anywhere EXCEPT AfricaThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.c. Modern H. sapiens migrating out of Africa were a biologically distinct species (very little interbreeding took place)4. Partial Replacement Model (Assimilation)a. AMHS originate in Africab. Replace ALL other populationsc. Earliest dates for African AMHS over 100,000yad. Moving to Eurasia, modern humans hybridized with resident groups, eventually replacing theme. The disappearance of archaic humans was due to hybridization and replacementWhat does the Evidence say?1. Fossil Evidencea. AMHS in Africai. Omo Kibish, Ethiopia 195,000ya1. Omo 1  chin and modern cranial characteristics2. Omo 2  more robust b. Humans in the Levantc. Modern Humans in Central Eruo 35,000kad. Asia 68ka2. Monti Lessini, Verona, Italy 34.5ka  human Neanderthal hybrida. Overall similar in shape to modern humansb. Mt DNA groups with NeanderthalsFossil Summary- H. sapiens first in AF 190kao No discontinuity in AF- Outside of Africa 90kao Despite discontinuity- Evidence for continuity in Asia is equivocalo Don’t resemble modern Chinese populations- Hybrid in ItalySupports out of Africa  Replacement / AssimilationArchaeological Evidence- Predictions:o Multiregionalism  Continuity of tool traditions in ALL areas of the worldo Replacement  Discontinuity of tool traditions Earliest evidence of tool should appear in Africa- Material Cultureo Continuous in Africa from 200ka Blades (twice as long as wide) Personal ornamentation Worker bone Cave art Animal engravingso Pinnacle Point, South Africao Blombos Cave 73ya Bone tools, beads and decorated ocher fragmentso Abrupt appearance in Europe ~45ka (Aurignacian)Supports the Replacement ModelGenetic Evidence- Molecular (gene) Clocko DNA mutations accumulate constantly over time More mutations… longer time since divergenceo Date when two species diverged: Counting number of mutations Calibrate against divergence date from fossil record- Mitochondrial Eve: Rebecca Cano 2 branches 1) African branch 2) Four other populationso Africa source of mitochondria gene poolo All other populations have multiple originso Calculate divergence: Woman in Africa, 200,000ya- Coalescence: genetic sequences from living individuals can be traced back to a common ancestorin the past- Mitochondrial (Vigalant)o 189 individuals o 121 Native Africans African pop had MOST diversity mtDNA Origins in Africa 200kya- Nuclear DNA (Kidd et al 2004)o African populations have more genetic variation than ALL other populationso Subset of African population migrated out ~100ka- DNA Evidenceo MRCA: one woman lived about 200ka, in Afo African pop are more diverse than all other populationsSupports REPLACEMENTA draft sequence of the Neanderthal Genome - 4 billion nucleotides from 3 Neanderthals- 5 present day humans from different parts of the world- Results:o Neanderthals are closer to Non African populationso Equally close to Europeans and East Asians 1-4% genetic contribution of Neanderthals to H. sapiens of European and Asian decent- Neanderthals and modern humans exchanged genes shortly after modern humans left AfricaSupports ASSIMILATIONSummary of Data1. Fossil Evidencea. Continuity in Africab. Hybrids in Europei. Out of Africa  Assimilation2. Archaeologicala. Continuity in Africab. Abrupt change in Europei. Out of Africa  Assimilation3. Mt DNAa. Af pop are older more diversei. Out of Africa (Total Replacement)4. Nuclear DNAa. Africa pop olderb. Neanderthals closer to Euro/Asiani. Out of Africa