Chapter 18, Problem 5FTB

Summary Introduction

To review:

The given blank space in the statement, “Species designations may change when researchers _________. The biological species definition is difficult to apply to organisms that __________. An alternative species definition, known as the _________, instead designates species on the basis of _________.”

Introduction:

The classification of species based on the hypothesis of evolutionary relationships shown by the three-domain system is revised when new data are available. Even the largest and oldest clade that also include the earliest branches of the tree also needs to be rearranged sometimes. These changes occur rarely at the top levels of classification, but among species designations, revision often occurs.