10.3 Gene Pools & Speciation

Essential Idea: Gene pools change over time

Understandings:

  • A gene pool consists of all the genes and their different alleles, present in an interbreeding population.
  • Evolution requires that allele frequencies change with time in populations.
  • Reproductive isolation of populations can be temporal, behavioural or geographic.
  • Speciation due to divergence of isolated populations can be gradual.
  • Speciation can occur abruptly.

Application:

  • Identifying examples of directional, stabilizing and disruptive selection.
  • Speciation in the genus Allium by polyploidy.

Skills:

  • Comparison of allele frequencies of geographically isolated populations.

Nature of science:

Looking for patterns, trends and discrepancies - patterns of chromosome number in some genera can be explained by speciation due to polyploidy. (3.1)

Introductory video:

Powerpoint

10.3 Gene Pool and Speciation HL.pptx