BIOB 272 1st editionLecture 1Outline of Last Lecture Human EvolutionI. Speciation Wrap-Up- Key PointsII. Human Evolution- A Speciation Case Study- Hominid vs. Hominin- Earliest Hominin Fossils Found- Speciation vs. AnagenesisIII. Earliest Hominin Ancestor? - Ardi- LucyIV. BipedalismV. Emergence of Large BrainsVI. Out of Africa Migration (3 waves)i. First Wave=1.8 MYA: Homo Erectusii. 2nd Wave= 400K-30K Neanderthalsiii. 3rd Wave= 100K Anatomically Modern Humansiv. Others?- The Flores HomininVII. Differing Hypotheses to Represent the Genetic History of Anatomically Modern Humansi. CandelabraThese 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.ii. Multiregional Evolutioniii. Replacementiv. AssimililationVIII. Mitochondrial DNA to Base Molecular Clock on the Migration of Hominins- Neanderthal Genome SequencingOutline of Current Lecture Human Evolution Day 2I. Neanderthals- Interbreeding- Genes Enriched/ De-enriched forII. Denisova Cave Hominin Inhabitation- Denisovans- High Adaptation to High Altitude- Tibetan and Han ChineseIII. “Leaky” Replacement Hypothesis for Expansion out of AfricaIV. What Makes us Human, Genetically?V. Evolution of Brain Regions Involved in LanguageCurrent LectureHuman Evolution Day 2VI. Neanderthals- Interbreeding= assimilation hypothesiso Slightly more closely related to all out of Africa population= about 2% of genomeo About 2% of out-of-Africa (OOA) genomes are Neanderthal derived- Genes Enriched/ De-enriched foro Average size 100kbo Enriched for: genes involved in keratin filaments=skin and hair. Disease-risk= lupus, cirrhosis, Crohn’s Disease, diabeteso De-enriched for: X chromosome. Genes involved in spermatogenesis=usually not in current male hominin genes= Neanderthals had a hard time with fertility?VII. Denisova Cave Hominin Inhabitation- for over 100 thousand years- Lots of fossils in the cave- pinky tip, large tooth, toe boneo Pinky tip: Unique because 70% of mtDNA usable= Most DNA ever to be usable from a single fossil from this time periodo Large tooth + the pinky tip mtDNA: uncovered an entirely new lineage of Neanderthals= Denisovans- Denisovans: “Third” lineage of Neanderthalso Pinky tip and toe of the Denisovan finds: Low genetic variation, brown hair/eyes, darker skin, young female, fossil about 80 thousand years oldo Early split within Neanderthal lineage, but with potential secondary contacto Slightly more closely related to people from Oceaniao 4-6% of genomeo Probably some breeding with modern anatomical humans passing by= introgression form Denisova likely was restricted to an earlier migration ofmodern humans= implies that Denisovans were much more widespread (than just in the cave location)- High Adaptation to High Altitude- Tibetan and Han Chineseo EPAS1 (associated with athletic performance)= descends form denisovans found in modern high altitude people in Tibetan and Han Chinese Associated with RBCs and hemoglobin concentrationVIII. “Leaky” Replacement Hypothesis for Expansion out of Africa- At Least two hybridization events resulting in gene flow into anatomically modern humans- There is genetic evidence for archaic admixture in Africa (Denisovans, etc.)IX. What Makes us Human, Genetically?- Chimp genome completed in Sept. 2005. Found chimps are 99% similar to humans= 35,000,000 single base pair differences= about 5 million insertion/deletions= 1 chromosome fusion. More genes involved in reproduction and immunity- Language?X. Evolution of Brain Regions Involved in Language- Arcuate Fasciculus= bundle of nerve fibers essential to language- shows strong expansion in the human brain- Forkhead box protein P2 (FOXP2)= a gene implicated in capacity for languageo FOXP2 Functioning copy of FOXP2= normal activity of Broca’s area (speech/language) Defective copy of FOXP2= reduced activity of Broca’s area and expansion of activity elsewhere Highly conserved in mammals, two amino acid changes in humans- including Neanderthals and
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