Chapter 23, Problem 1DA

Construct a data matrix like the one in figure 23.2, showing the character states for all six species for the traits hair, amniotic membrane, and tail.

Summary Introduction

To determine: Thematrix of six animal species showing different vertebrate characters.

Introduction: The phylum chordate contains various divisions and among them the vertebrate forms a significant category. The division vertebrate contains Reptilia, Pisces, Amphibia, Mammalia, and Aves. The advanced animals evolved from Pisces and continued through amphibian, reptiles, birds to mammals.

Explanation of Solution

The matrix of six animal species showing different vertebrate characters.

Traits: Organism	Amniotic membrane	Hair	No tail
Lamprey	0	0	0
Shark	0	0	0
Salamander	0	0	0
Lizard	1	0	0
Tiger	1	1	0
Gorilla	1	1	1
Human	1	1	1

Table 1: The matrix of six animal species showing different vertebrate characters.

Embryonic development is a complicated process where a vast number of genes and signaling methods are required to accurately form the differentstructures of the growing fetus. The chordates share a large number of characteristics with the deuterostomes that indicate the origin of the chordates from the deuterostomes.

The features common to both deuterostomes and chordates include the presence of radial cleavage, first embryonic opening forming the anus. The vertebrates share unique characters that demarcate them from invertebrates and these include presence of hair, tail, and amniotic sac, which is not present in invertebrates.