Darwin’s finches originally occupied the South American mainland. When a group of these finches populated the Galapagos Islands, competition for food occurred between individuals in the population. Over time, the subgroups of these finches adapted to different food sources, resulting in a variety of finches with differing beak sizes and shapes. Which type of evolution is described within this example?

Quite often we see organisms that have similar characteristics, not because they have arisen from a common ancestor, but because they have adapted to similar environments. Which type of evolution is this?

Some scientists suggest that the mass extinction of dinosaurs resulted from sudden global weather changes caused by the impact of an asteroid on Earth. This event most likely promoted the evolution of new species of animals. What concept is best supported by these ideas?

In the diagram, B, C, and D represent organisms that exist in the present time and show a striking similarity to each other in their bone structure. In this diagram, what does letter A most likely represent?

In the frigid waters of the ocean surrounding Antarctica, fish have a special trait which allows them to survive the big chill. As scientists discovered in the 1960s, the fish have adapted by evolving a kind of antifreeze. It's composed of molecules called glycoproteins that circulate in the blood of the fishes, slightly lowering the temperature at which their body fluids would otherwise freeze and kill them. The glycoproteins surround tiny ice crystals and keep them from growing. The fish at the other pole of the globe also have a similar protein. It was, however, seen as a mutation after they had diverged from the southern species.

What pattern of evolution does this example demonstrate?

The Rough-skinned newt produces a potent neurotoxin that concentrates in their skin. Garter snakes, have evolved resistance to this toxin through a series of genetic mutations, and prey upon the newts. The relationship between these animals has resulted in an evolutionary arms race that has driven toxin levels in the newt to extreme levels.

What pattern of evolution does this example demonstrate?

The Apple Maggot Fly infests the fruit of a native North American Hawthorn Apple tree. In the 1860s some maggot flies began to infest apples. Now there are two populations of the fly feeding on the two food sources. The populations rarely interbreed and are showing genetic differences and therefore are becoming two separate species.

What pattern of evolution does this example demonstrate?

Hummingbirds have a beak just the right length to reach the nectar in a cardinal flower and as they feed their foreheads bump into the pollen structure. Cardinal flowers are red which hummingbirds can see but bees can’t. Cardinal flower’s pollen structure is just the right length for the hummingbird to pick up pollen as it feeds.

What pattern of evolution does this example demonstrate?