Essential Knowledge 1.C.2

Speciation may occur when two populations become reproductively isolated from each other.

Speciation results in diversity of life forms. Species can be physically separated by a geographic barrier such as an ocean or a mountain range, or various pre-and-post-zygotic mechanisms can maintain reproductive isolation and prevent gene flow.

New species arise from reproductive isolation over time, which can involve scales of hundreds of thousands or even millions of years, or speciation can occur rapidly through mechanisms such as polyploidy in plants.

Students should be able to:

LO 1.22 Use data from a real or simulated population(s), based on graphs or models of types of speciation, to predict what will happen to the population in the future.

LO 1.23 Justify the selection of data that address questions related to reproductive isolation and speciation.

LO 1.24 Describe speciation in an isolated population and connect to to change in gene frequency, change in environment, natural selection and/or genetic drift.