Chapter 17, Problem 38A

Summary Introduction

To identify:

The group to which crustaceans are most likely to be related

Introduction:

A cladogram is a branching diagram that represents that proposed phylogeny or evolutionary history of a species or group. A clade is one branch of the cladogram. Shared derived characters are used to construct a cladogram.

Answer to Problem 38A

Insects

Explanation of Solution

The branch of a cladogram indicates phylogeny. The closeness of clades in the cladogram indicates the number of characters shared. The group that is closest to crustaceans shares the most derived characters with crustaceans and thus shares a more recent common ancestor with crustaceans than with the groups farther away.

According to the cladogram given by Hwang et al on the right, crustaceans are most likely to be related to the group of insects as the branch of crustaceans is joined to insects and they share a common ancestor.