Uncommon ancestors


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Uncommon ancestors

  1. 1. Uncommon Ancestors Razib Khan A fashionable Neanderthal ancestor in feathers
  2. 2. In the beginning....
  3. 3. Charles Darwin, up from apes
  4. 4. Out of Africa, according to Darwin <ul><li>Monogenism, all races have a common origin
  5. 5. vs. polygenism, dominant position </li></ul>
  6. 6. Modern scientific polygenism
  7. 7. Modern scientific monogenism
  8. 8. 1987, “Out of Africa” monogenism victorious!
  9. 9. Cultural impact of “Out of Africa”
  10. 10. 1987, “mitochondrial Eve” <ul><li>Africans basal
  11. 11. Africans more diverse
  12. 12. Non-Africans “branch” of Africans
  13. 13. Implies recent African origin of all of humanity </li></ul>
  14. 14. Consensus since 1987 <ul><li>Y chromosomal “Adam” indicates African origin </li></ul>
  15. 15. The total genome supports African origin
  16. 16. Skulls don't lie, Africans had modern skulls first
  17. 17. How about Neanderthals? <ul><li>Ancient mtDNA was extracted and compared to modern human mtDNA </li></ul>
  18. 18. In a sentence..... <ul><li>Everyone alive today is descended from a small group of African hominins who flourished 100-200,000 years ago, and whose descendants left their home continent and replaced all other human lineages in totality </li></ul>
  19. 19. Case closed, we won, they lost?
  20. 20. 2010, The End of the Orthodoxy <ul><li>Researchers extracted DNA from fossils, and reconstructed the genomes of ancient humans, and compared them to modern populations </li></ul>
  21. 21. How Do These Populations Relate
  22. 22. How Do “They” Relate To “Us”
  23. 23. Top line, circa 2011 <ul><li>All non-Africans have 2.5% Neanderthal ancestry </li></ul>
  24. 24. Living “Archaic” Humans
  25. 25. The Neanderthal (gene) in my family <ul><li>Dystrophin gene, skeletal and muscular development </li></ul>
  26. 26. ~10% of non-Africans have a Neanderthal dystrophin variant <ul><li>A sequence of markers which seems to match the one in the Neanderthal reference genome </li></ul>
  27. 27. About dystrophin <ul><li>On X, so men have 1 copy, women 2
  28. 28. Is why most of “Jerry's kids” are male
  29. 29. “Big” gene, huge RNA transcript
  30. 30. Critical to skeletal muscle development </li></ul>
  31. 31. Me, myself, & genotyping <ul><li>Who carries the Neanderthal haplotype? </li></ul>
  32. 32. My Neanderthal brother? <ul><li>I share 53% of genes with my brother, 1 standard deviation above the expected value
  33. 33. We look very similar....
  34. 34. Except, he is considerably more “robust”
  35. 35. Coincidence? </li></ul>
  36. 36. More than just ancestry <ul><li>In the near future you will likely be able to know which genes you carry the Neanderthal variants </li></ul>
  37. 37. Who cares? <ul><li>Many of you have been part Neanderthal your whole life. Now you know!
  38. 38. Are you inferior to those who aren't part Neanderthal?
  39. 39. Or are they inferior to you?
  40. 40. Does Neanderthal make you superior, and Denisovan make Papuans inferior? </li></ul>
  41. 41. Are we no longer brothers? <ul><li>In 1988, in reaction to “mitochondrial Eve” Stephen Jay Gould stated: &quot;If it's correct, and I'd put money on it, this idea is tremendously important,&quot; says Stephen Jay Gould, the Harvard paleontologist and essayist. &quot;It makes us realize that all human beings, despite differences in external appearance, are really members of a single entity that's had a very recent origin in one place. There is a kind f biological brotherhood that's much more profound than we ever realized.&quot;' </li></ul>