23. Speciation

Which of the following is the primary criteria for defining species based on the biological species concept?

Giraffes live throughout large regions of Africa. Historically, only one species of giraffe has been recognized, but many scientists argue that giraffe populations actually represent four distinct species. What piece of evidence would best determine whether different giraffe populations should be considered different species according to the biological species concept?

Which of the following describes a postzygotic barrier?

Abalone, a type of sea snail, are broadcast spawners, meaning they release their gametes into open water, where the sperm and egg drift until they meet and fertilization occurs. The sperm of the red abalone does not recognize the eggs of the pink abalone and vice versa due to biochemical incompatibilities. This is an example of what type of reproductive barrier?