ISS 210 1st Edition Lecture 9 Outline of Last Lecture I The Neanderthal Stereotype II Burial of the Dead III H neanderthalensisi saccopastore 1 IV Neanderthal Human Skeletons V Neanderthal Grip and Thighs VI Homo sapiens idalto elder VII Quafzeh 1X adult female VIII Blombos cave South Africa IX Homo Sapiens becomes a uniquely dangerous competitor X Multi regional continuity model XI Testing the multiregional hypothesis XII Ecological Collapse 40 kya Outline of Current Lecture I Testing the Multiregional hypothesis II Human and Neanderthal MTDNA III Y guys have it rough IV The m y t maternal mitochondria V Haplogroupies on the clock VI Out of Africa VII Middle Eastern male migration VIII North America migration IX Other Evidence X Lice Phylogeny Current Lecture I II III IV Testing the Multiregional hypothesis If there is a pattern of shared genomes among all archaic humans If the H neanderthalsensis genome is more closely related to some Homo sapiens than the various Homo sapiens are to each other then the multiregional hypothesis is supported If the H neanderthalensis genome is less closely related to those of Homo sapiens than the various Homo sapiens are to each other then the replacement hypothesis is more viable Human and Neanderthal MTDNA DNA is difficult to isolate in fossilized material and degrades into their fragments over time 40000 years was considered the upper limit Scientists have sequenced Neanderthal mDNA for 8 individuals The 60000 year old Mungo 3 fossil from Australia provided ardaic human mtDNA Scientists obtained mtDNA from 9 other archaic individuals Samples of 3000 living Homo sapiens Homo sapiens most likely did not interbreed with Neanderthals Supporters center of origin hypothesis Y guys have it rough The y chromosome is slowly deteriorating and in 5000 generations 125000 years will be eliminated from the genome leaving only one sex female Females have XX and males XY Sons and daughters get X from their mother Only half the male sperm has Ys making the XY ration 3 1 Males are X challenged the mothers X pairs with the fathers Y so theres only one chance to get the X chromosome right making males more prone to the expression of deleterious traits caused by defective genes in the X chromosome Y chromosomes don t recombine creating an unbroken male lineage that allows scientists to track how males spread across the world The m y t maternal mitochondria Male mtDNA don t get into the egg when fertilization occurs and the egg cell destroys them f any do Mothers pass their mtDNA to their offspring Males do not pass it to the next generation Daughters do this maintaining a strict mother to daughter transmission of mitochondria genomes mtDNA do not recombine allowing scientists to track how females spread across the world The mtDNA of all homo spapiens populations ponts back some 2000000 years to a single female ancestor or more precisely to 18 mitochondrial eve lineages Y chromosomes trace male descent but so far only 10 adam lineages have been defected Molecular clocks Genes accrue mutations ticks at different rates The D loop a region of mtDNA doesn t make a protein and accumulates more changes faster than the rest of the mitochondrial genome The introns on the Y chromosome don t make proteins either and accumulate changes faster Differences can be used to infer divergence but fossil dates if available are better because radioisotope clock ticks more regularly V Haplogroupies on the clock Alan Templeton and Coalescence Analysis First wave of humans left Africa 1 7 mya Second wave of humans left Africa 5000000 years ago and interbred with the descends of the first wave Third wave of Homo sapiens left Africa 80000 VI VII VIII IX X Out of Africa Based on the Y chromosomes collected from men who self identify as Jews Palestinians or Kurdish Muslims researchers were unable to differentiate the Y chromosomes The various thnic groups are highly interconnected Middle Eastern male migration The indian mtDNA and Y chromosomes show initial migration along the south coast Northeaster Indian closer to east Asians than the South Indians The discover of European or Aryan Y chromosomes but no mtDNA suggested an invasion by European males 3 4000 years ago married local women North America migration 3 wave theory 20 15k for Amerind 10K for Nadene 7K for Eskaleuts 2 wave theory 15K supports a pre clovis entry 12 5K Glacier recession mtDNA X marker confirms a north south cline suggesting that all 3 group originating in Siberia populated North America first then gradually moved south Other Evidence Khoi San lineage split off 150 100 K marked by click languages Bantu lineages start to expand about 60K Click sounds and hunting The hepatitis G virus does not cause liver damage originated in Africa and followed human migrations across South Asia Helicobacter pylon a bacterium that causes stomach ulcers traces from east Asia to South American natives Oceanic rats hitching rides with Polynesians are distinct from European rats that arrived later Lice Phylogeny Two lineages of lice inhabit H sapien These lineages split 1 2 mya when H sapiens and H erectus split And re inhabits H sapiens suggesting contact between the species