Study Guide

Animal Evolution and Diversity Topics

What is an Animal?

We know one when we see one. A dog is an animal. We are animals. What about a sponge? Sponges are...

Animal Evolution

Life on Earth didn't start out with animals. All life on earth started from the primordial ooze,...

The Animal Family Tree

We are family. All animals are related, but figuring out the relationships is not...

Let the Food Come to Them

It's alive! Sponges are animals, the oldest ones around. The first branching in the animal family...

Polyps and Medusas

This is the beginning of the rest of the animal kingdom, the eumetazoa, or "true animals" (we...

Get A-head

From here on out, we're going to be talking about the Bilateria, or animals that have a body plan...

Invertebrates Get More Complex

The rest of the animal kingdom fits nicely into the next two big branches of the animal family...

What's In a Worm?

Segmented worms like earthworms and leeches are found all over the place—from our compost...

Life Takes to the Land

We see arthropods everywhere we go. Arthropoda, the third protostome phylum, is everywhere....

Controversial Cousins

Four invertebrate phyla remain to be discussed: Phoronida, Bryozoa, Brachiopoda, and...

Get a Backbone

When we think "animal," we usually think of a vertebrate. Sorry, we're a bit biased. We'll first...

Vertebrates Take to the Beach

First, the ancestors of frogs and salamanders crawled out of the deep blue sea. Then, for a...

Birds

If there is space, someone will move in. With flying dinosaurs going away, airspace opened for...

Cute and Furry

Mammals evolved from reptile ancestors, just like birds. Mammals, however, came first and they...

Primates

You'll appreciate your thumb so much more after this.We are primates, as are monkeys, apes, and...

Common Mistakes

When we think of life, we generally remember plants and animals. Try a mnemonic to get them...

Test Your Knowledge

1. The six kingdoms of life are:2. Animals are:  a. Prokaryoticb. Heterotrophicc....