Practice Questions

1.What is speciation?

Speciation is the formation of new species from an existing species.

2. A population of birds becomes separated by a river. Explain how this can lead to the formation of two species.

A population has variation due to different alleles. When the birds are separated by a river, they become isolated and cannot interbreed. Each group experiences different selection pressures in their environments. Natural selection leads to different adaptations in each group. Over time, genetic differences increase until they can no longer interbreed to produce fertile offspring, forming two species.

3.Describe the contribution of Alfred Russel Wallace to evolutionary theory.

Alfred Russel Wallace independently proposed the theory of evolution by natural selection. He collected evidence from around the world to support this idea. His work led to the joint publication with Darwin in 1858, which helped establish the theory.