Chapter 23, Problem 1S

Summary Introduction

To enlist:

The synapomorphy and the taxa defined by that synapomorphy for the groups pictured in figure 23.2. Name each group defined by a set of synapomorphies in a way that might be constructed as informative about what kind of characters define the group.

Introduction:

Systematics is used to construct a phylogeny which is an evolutionary tree that depicts the relationship among different species by studying the similarities or differences among different species. But similarities could arise either due to ancestral basis or due to derived characters like homoplasy or convergent evolution. Cladistics is the approach that distinguishes between the similarities due to ancestral reasons from the similarities due to derived characters.

Synapomorphic characters are those that are shared only by the descendants of an ancestral species.