Neandertals: recent archaics

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Neandertals recent archaics

• Lived in a time-range 100,000 - 28,000 ya
• Shared Europe with modern H. sapiens for c.
  12,000 yrs.
• Brain was, on average, larger than that of modern
  humans 1410 vs. 1330 cc
• Height 4.9 - 5.6 ft.
• Weight 110 - 143 lb.
• Heavier bones, more muscular
• Differ in skull, limb proportions, and
  semicircular canal structure.

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How to classify?
?
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Skull differences




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A neandertal
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Neandertal sites Note not in Africa
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Mousterian stone culture Neandertals
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Artifacts of teeth and ivory Dated at 45,000
ya From a site in France Neandertal bones at site
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The origin of modern humans Known modern humans
first appear in fossil record c. 190,000 ya in
Africa 115,000 ya in Mideast 60,000 ya Asia
Australia 40,000 ya in Europe
Two competing hypotheses
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Intermediacy between H. heidelbergensis and H.
sapiens Herto, Ethiopia, Africa 160,000 ybp
(argon-argon dating)
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Genetic predications distinguishing STRICTLY
African replacement and multi-regional evolution
models

• 1. Location of ancestor of neutral alleles
• 2. Divergence time of African vs. non-African
  populations
• 3. Genetic diversity
• 4. Sets of neutral alleles

• AR mostly Africa MRE random
• AR 200,000 yr or less MRE 1 mya or greater
• AR greater in Africa MRE approx. equal in all
  regions
• AR European Asian alleles are subsets of
  African alleles
• MRE each region has some unique alleles
• No regions alleles are a subset of those from
  another region

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Predictions from each model
1. the extinct archaic and extant modern humans
in each region will be each others closest
relatives
Lieberman (1995)
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mtDNA All human groups equidistant
from Neandertals Modern human lineage
diverged after it split from lineage leading to
Neandertals Last common mitochondrial ancestor
of Neandertals and modern humans 690-357 ya
352-151 kya
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Predictions from each model
1. all groups of modern humans will be more
closely related to each other than to any archaic
species. 2. among archaic species, those from
Africa will be the most closely related to
modern humans
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53 individuals complete sequence of mtDNA
Common ancestor of all modern mtDNAs lived in
Africa
B

• Most recent common
• ancestor of all modern mtDNA
• Most recent common
• ancestor of Africans and
• non-Africans

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Consistent with African Replacement Model
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Comparison of genetic variation (mtDNA)
Chimpanzee subspecies are more genetically
variable than any two human populations
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Phylogeny of 14 populations based on allele
frequenciesat 30 microsatellite loci and genetic
distances

• Geographically neighboring populations cluster
  together
• Basal branch separates African and non-African
  groups
• Split estimated from this data 75,000 to
  287,000 ya
• Consistent with African Replacement Model

Bowcock, Ruiz-Linares, Tomfohrde, Minch, Kidd,
and Cavalli-Sforza (1994)
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• Genetic diversity at a single locus in chromosome
  12 among people of 7 geographic regions 12
  different alleles
• Each plot shows the frequencies of the various
  alleles for people of a particular region.
  Arranged by travel distance.
• If non-African populations were founded by small
  bands of people migrating out of Africa, then
  non-African populations should have reduced
  genetic diversity.
• 1. African populations show much greater allelic
  diversity than non-African populations
• 2. Consistent with African replacement model.

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Competing hypotheses
Paleontological evidence
Milford Wolpoff
Richard Klein
Phillip Rightmire