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Draft Sequence of Neandertal Genome
Jun. 30th, 2012 01:43 pmpreviously only mitochondrial DNA had been done? not clear on this part
contamination with microbial DNA and also human DNA
also, most human and Neandertal DNA expected to be the same, so contamination hard to distinguish from endogenous
compare to chimp, human, rhesus, and mouse
whatever's closer to a chimp may be
PCR techniques to get as much DNA as you can out of very little bone powder, relatively little destruction to the bones
pick bones that are morphologically uninteresting
enzyme to get rid of microbial DNA
also biased toward getting rid of some endogenous DNA, which makes it not useful for obtaining a whole genome
500,000 years ago common ancestor with Neanderthals, meaning even without gene flow, some Neanderthals expected to be more closely related to some humans than others. Have to compare populations, not individuals.
taste receptor gene, language-related FOXP2, ABO blood group, and skin pigmentation
identified sites where the human sequence does not match the chimp, orangutan, rhesus macaque
features that are fixed in the human genome but the neanderthal genome carries the ancestral allele are of special interest
there are relatively few of these
human accelerated regions are ones where we diverge greatly from chimps
neanderthals share 91% of these
however, there are still 51 such positions where Neanderthals carry the ancestral version
look for places where humans share a common ancestor post-dating the split between Neanderthals and humans
population divergence vs gene sequence divergence
population divergence is more recent
human and neanderthal populations diverged 270,000 - 440,000 years ago
compatible with some interpretations of the paleontological record
neanderthals closer to non-Africans than to Africans
equally close to Europeans and east Asians
almost all of the gene flow detected was from Neandertals into humans
Neandertals equally similar to Chinese, Papuan, and French individuals
suggesting mixing was early and with an ancestor of all those people, i.e. probably a bottleneck of homo sapiens sapiens leaving Africa, mingling with Neandertals in the Middle East, and then spreading out over Europe
modern humans appeared in the Middle East over 100,000 years ago
however, old population substructure in Africa remains a possibility, although not a widely supported one
contamination with microbial DNA and also human DNA
also, most human and Neandertal DNA expected to be the same, so contamination hard to distinguish from endogenous
compare to chimp, human, rhesus, and mouse
whatever's closer to a chimp may be
PCR techniques to get as much DNA as you can out of very little bone powder, relatively little destruction to the bones
pick bones that are morphologically uninteresting
enzyme to get rid of microbial DNA
also biased toward getting rid of some endogenous DNA, which makes it not useful for obtaining a whole genome
500,000 years ago common ancestor with Neanderthals, meaning even without gene flow, some Neanderthals expected to be more closely related to some humans than others. Have to compare populations, not individuals.
taste receptor gene, language-related FOXP2, ABO blood group, and skin pigmentation
identified sites where the human sequence does not match the chimp, orangutan, rhesus macaque
features that are fixed in the human genome but the neanderthal genome carries the ancestral allele are of special interest
there are relatively few of these
human accelerated regions are ones where we diverge greatly from chimps
neanderthals share 91% of these
however, there are still 51 such positions where Neanderthals carry the ancestral version
look for places where humans share a common ancestor post-dating the split between Neanderthals and humans
population divergence vs gene sequence divergence
population divergence is more recent
human and neanderthal populations diverged 270,000 - 440,000 years ago
compatible with some interpretations of the paleontological record
neanderthals closer to non-Africans than to Africans
equally close to Europeans and east Asians
almost all of the gene flow detected was from Neandertals into humans
Neandertals equally similar to Chinese, Papuan, and French individuals
suggesting mixing was early and with an ancestor of all those people, i.e. probably a bottleneck of homo sapiens sapiens leaving Africa, mingling with Neandertals in the Middle East, and then spreading out over Europe
modern humans appeared in the Middle East over 100,000 years ago
however, old population substructure in Africa remains a possibility, although not a widely supported one
