Genes in human populations

1
Genes in human populations

• Population genetics focus on allele frequencies
  (the gene pool all the gametes in a big pot!)
• Hardy-Weinberg calculations (e.g., p2 2pq q2)
  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)

2
DNA typing and forensics

• Common genetic polymorphisms
• RFLPs
• VNTRs
• Microsatellites
• 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)

3
Conservation of genomic segments (haplotypes)
The HapMap

• 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
• Most population share common SNP variants and
  haplotypes
• Haplotype blocks and the tag SNPs that identify
  them will form the HapMap