Population Subdivision

• We’ve been considering single pops

  • most species are subdivided into subpops

• Understanding patterns and extent of genetic divergence among pops important for:

  • protecting spp

    • Distinct pops can be listen under ESA

    • translocations among distinct pops may have harmful effects

  • Developing conservation plans

    • gene flow

    • adaptive genetic variation

Migration vs. dispersal

• pop genetics:

  • migration/gene flow: movement of individuals from one genetic pop to another + reproduction

  • in ecology, dispersal is the movement from one pop to another and migration is (usually) the seasonal movement of individuals from one geographic area to another

• subpops connected by some amount of gene flow

• how is variation distributed?

  • gene flow vs. drift at neutral loci

  • effects of selection on distribution of genetic variation

F-stats

• genetic variation in spp exists at 2 levels

  • within local pops

  • between local pops

• f-stats are used to measure genetic differentiation using a series of inbreeding coefficient