Species can split to form several new populations if they evolve separately. Populations may not be able to respond and go extinct. More offspring e. Fitness increases chance of survival 8. Changing Environments a. Broad range of variations i. more likely to have some individuals survive.
Species is subdivided i. part of the species is isolated from another part.
After divergence, geographic range can overlap. Genetics A. Darwin 1. No explanation for variation within a species and how variation arises 2. Genetics unknown at that time. B. Genetics 1.