The Evolution of Invertebrate Diversity

What is an Animal? Well, an animal is a multicellular, heterotrophic eukaryote that has a unique cell structure and occupation (cells are specialized for a certain function) to obtain nutrients by ingestion. Another distinguishing characteristic of an animal is its ability in varying life cycles and embryonic developments.

Animal Diversification started more than half a billion years ago Some of the oldest fossils are from the Ediacaran period which was around 575 to 525 million years ago. This is around the same time period when animal diversification accelerated rapidly, which came to be known as the "Cambrian explosion" (535 to 525 million years ago).	Animal Characterization is done by using basic features of their "body plan" Symmetry Radial Bilateral Body Cavity None Pseudocoelom True Coelom Embryonic Development Protostomes Deuterostomes	Phylogenetic Tree animal body plans are used to build phylogenetic trees. Morphology-based Phylogenetic tree of the major phyla of the animal kingdom

Animal Evolution and Diversity