Chapter 15, Problem 32A

Summary Introduction

To conclude:

About the evolutionary process that produces two unrelated species that share similar niches on different continents

Introduction:

For speciation to occur, a population must diverge and then be reproductively isolated. Many details of speciation process remains to be a mystery. Speciation is a long process and first- hand accounts of it are rarely available. However, evidence of speciation is visible in patterns of evolution.

Answer to Problem 32A

The evolutionary process that produces two unrelated species that share similar niches on different continents is convergent evolution.

Explanation of Solution

When unrelated species evolve similar traits even though they live in different continents, it is called convergent evolution. It occurs in environments that are geographically far apart but have similar ecology and climate.

For example the mara and the rabbit are unrelated, but they inhabit similar niches and so they have evolved similar morphology, physiology and behavior. The South American mara inhabited a niche that was occupied by the rabbit in Europe. The mara was more similar to other South American species than it was to rabbit because it shared a closer ancestor with the South American animals. Convergent evolution can also be seen between Australian marsupials and the placental mammals of other continents.