Whales are aquatic mammals that contain a pelvis (hip) bone. Even though it does not aid in its movement, the function must have been used by a common ancestor of the whale. Thus, the pelvis is referred to as a(n)

Which organism is LEAST closely related to humans?

Male bearded dragons bob their head to attract mates. Males compete for females.

Which condition for natural selection is seen above?

Zebras have limited food availability due to droughts.

Which condition for natural selection is seen above?

Spotted leopards and black leopards are the same species. Spotted leopards can give birth to black leopards.

Which condition for natural selection is seen above?

A group of giraffes all have different spot patterns. Some are dark, some are light, some are large patches, and some have small spots.

Which condition for natural selection is seen above?

Some female peacocks prefer males with large, colorful tales while other female peacocks prefer males with no tail at all. Females are now mating only with the tail they prefer. What type of reproductive barrier is this?

In the Great Lakes region of North America, gray wolves and coyotes are similar species but do not mate because their breeding periods occur at different times of the year.

The females of two species of fruit fly, Drosophila melanogaster and Drosophila simulans release slightly different mating hormones called pheromones, which are used to attract male mates.

The American toad (Anaxyrus americanus) and Fowler's toad (Bufo fowleri) live in the same area. However, The American toad mates in early summer while Fowler’s mates in late summer.

Albert’s squirrel and the Kaibab squirrel are distinct subspecies that live on opposite sides of the Grand Canyon. They were once one species, but now differ significantly, including fur coloring.

Earth's early atmosphere had no