Chapter 23.5, Problem 2SB

Summary Introduction

To review:

The difference between the morphological changes predicted by phyletic gradualism hypothesis and punctuated equilibrium hypothesis.

Introduction:

Over a period of time, many morphological changes have occurred in organisms. These changes have taken place gradually over long periods of time. For example, morphological change in rodents occurred over a period of time. An increasing trend was seen toward the larger size of rodents. Change in the cranial and mandibular size of an old field mouse is another example of it.