Genes in human populations n Population genetics: focus on allele frequencies (the “gene pool” = all the gametes in a big pot!) n Hardy-Weinberg calculations (e.g., p 2 + 2pq + q 2 ) assume: –Mating is random (but there is stratification and assortative mating) –Population is large (if appropriately chosen!) –No mutation (but there is) –No migration (but migration occurs) –No selection (but there can be selection)

DNA typing and forensics n Common genetic polymorphisms –RFLPs –VNTRs –Microsatellites n For each variable locus, the frequency of alleles in a population can be determined - suspect typed for many loci and probability of match determined (exclusion criteria)

Conservation of genomic segments (haplotypes): The “HapMap” n In populations, it appears the the linear order of alleles (“haplotype”) is conserved in uninterrupted blocks or “neighborhoods” that tend to be inherited together, with recombination occurring between them n Most population share common SNP variants and haplotypes n Haplotype blocks and the tag SNPs that identify them will form the HapMap