including the differences between sea robin species and the genetics responsible for their unusual traits, such as leglike fins that have evolved so that they largely function as sensory organs.

As the spring months arrive, so do the American robins, and many can be seen foraging for their favorite food in the ground.

This species’ often confiding nature, distinctive plumage, pleasing song, and acceptance of human-dominated habitats make it one of the most beloved of North American birds. Polytypic.

The five kingdoms are: The binomial system is important because it allows scientists to accurately identify individual species. For example, the European robin is Erithacus rubecula. It is much ...