3. Human population migrations Out of Africa, Replacement –Single mother of all humans (Eve) ~150,000yr –Single father of all humans (Adam) ~70,000yr –Humans out of Africa ~40000 years ago replaced others (e.g., Neandertals) –Evidence: mtDNA, Y chromosome Multiregional Evolution –Fossil records show a continuous change of morphological features –Proponents of the theory doubt mtDNA and other genetic evidence

4. Why humans are so similar A small population that interbred reduced the genetic variation Out of Africa ~ 40,000 years ago Out of Africa

5. Migration of Humans

6. http://info.med.yale.edu/genetics/kkidd/point.html

7. Migration of Humans

8. http://info.med.yale.edu/genetics/kkidd/point.html

9. Human Variation in the Y Chromosome

10. Some Key Definitions Mary: AGCCCGTACG John: AGCCCGTACG Josh: AGCCCGTACG Kate: AGCCCGTACG Pete: AGCCCGTACG Anne: AGCCCGTACG Mimi: AGCCCGTACG Mike: AGCCCTTACG Olga: AGCCCTTACG Tony: AGCCCTTACG Mary: AGCCCGTACG John: AGCCCGTACG Josh: AGCCCGTACG Kate: AGCCCGTACG Pete: AGCCCGTACG Anne: AGCCCGTACG Mimi: AGCCCGTACG Mike: AGCCCTTACG Olga: AGCCCTTACG Tony: AGCCCTTACG Alleles: G, T Major Allele: G Minor Allele: T G/G G/T G/G T/T T/G G/G G/T G/G T/T T/G Recombinations: At least 1/chromosome On average ~1/100 Mb Linkage Disequilibrium: The degree of correlation between two SNP locations MomDad

11. The Fall in Heterozygosity

13. The HapMap Project

15. The HapMap Project – Haplotype Blocks

16. The HapMap Project – LD

17. Fixation, Positive & Negative Selection Neutral Drift Positive Selection Negative Selection How can we detect negative selection? How can we detect positive selection?