The unusual distribution of marsupials in Australia and the Americas can be explained partly by:

The fossil record provides evidence for evolution because it shows that:

Which combination of evidence provides the strongest support for the theory of evolution?

Why might microbial samples help distinguish between people who have touched the same type of surface?

Species living on different islands often evolve unique characteristics because:

The forelimbs of humans, whales, bats, and alligators contain many of the same bones arranged in a similar pattern. This similarity is an example of:

A paleontologist finds two fossils in different sedimentary rock layers. The fossil found deeper in the rock is most likely:

What important result came from the Miller-Urey experiment?

It takes 10 to 14 days for a person to show symptoms of typhoid.

In 1906, it was estimated that 10,000 people died of typhoid in America.