We are all vertebrates, or animals with backbones. Vertebrates use their backbones for movement and support. Vertebrates share other traits as well: an internal skeleton, muscles, a protective skin, blood that circulates through vessels, and an advanced nervous system, including a head with a brain. Image credits: main image, cat skeleton.

Select one: a. several populations of Homo ergaster that existed in Asia, Africa, and Europe b. one population of Homo ergaster and the other populations were supplanted by H. sapiens c. old world monkeys d. new world monkeys e. chimpanzees Click the card to flip 👆 Definition 1 / 25