Duck

Otter

Echidna

Platypus

Begin

Duck

Otter

Echidna

Platypus

It took millions and millions of years for plants and animals to adapt, change and evolve into the variety of species that now exist on Planet Earth. Because of this, some animals may have more in common than you realize.

Your Mission:

You will be investigating three lines of evidence that scientists use to establish common ancestry among species.

Duck

Otter

Echidna

Platypus

First, let's take a closer look at four animals that seem to share some common traits.

Click on each animal to learn their key stats.

Consider:

Of the platypus, echidna, otter and duck, which two species do you think are most likely to be related?

Embryology

To really investigate which two species are most closely related, you'll need more information and access to a real science laboratory. Join us at the Zoo Lab as we work together with scientists to learn more about each of these animals.

Two different word parts make up the word Embryology. The suffix "ology" means "the study of." The root word "Embryo" describes an unborn animal or human at one of its earliest forms of development.

Embryos that show distinct similarities likely descended from a common ancestor.

Chicken

Human

Fish

For example, the embryos of chickens and humans have slits on their necks that look very similar to the gills of fish. While chickens and humans don't actually develop these gills, the presence of these slits in their embryos is just one piece of evidence that helps scientists determine whether all three animals share common ancestry.

Illustrations are meant for instructional purposes only and are not scientific drawings.

In the Embryology Room, you'll be able to compare and contrast platypus, echidna, otter and duck embryos at three different stages in search of distinct similarities.

Click on each of the animals to see what they looked like in their youngest form, and then try to order the embryos from youngest to oldest.

EMBRYOS

Now that the embryos are organized, they're ready to study for similarities.

Based upon characteristics found in each set of embryos, choose which two animals are most similar.

Then, click on your notebook to record your findings.