Evolutionary Traits of Marine Mammals

What are the two primary claims made by the theory of biological evolution regarding living creatures?

• All living things are related and evolution is powered by natural processes.

• All living things are related and evolution is powered by supernatural forces.

• Living things are unrelated but evolve through natural selection.

• Living things are unrelated and evolve through supernatural forces.

Which of the following characteristics is shared by whales and land mammals, but not by fish?

• Having gills for breathing.

• Being cold-blooded.

• Giving live birth and feeding milk to their young.

• Having scales on their skin.

What anatomical feature found in modern whales provides evidence of their evolutionary past as four-legged land mammals?

• Their blowholes on top of their heads.

• The presence of hair or whiskers.

• Vestigial hip, thigh, and shin bones.

• Their flippers containing arm, wrist, hand, and finger bones.

During the embryonic development of a dolphin, what happens to the leg buds that initially form?

• They grow into fully functional hind legs.

• They develop into the dolphin's flippers.

• They grow for a while and then fade away.

• They transform into the tail fluke.

Where is the nasal opening located on the skull of a Basilosaurid whale?

• At the very end of the snout, like land mammals.

• On the top of the head, like modern whales.

• In the middle of the skull, between the snout and the top of the head.

• Basilosaurid whales do not have nasal openings.

What was the likely function of the small, fully developed hind limbs found on Basilosaurid whales?

• They were used for walking on land.

• They were essential for efficient swimming and propulsion.

• They may have been useful for mating or scratching away parasites.

• They served no functional purpose and were vestigial structures.

Which combination of features suggests that Maiacetus inuus was a 'walking whale' capable of both land and water movement?

• Its large, powerful tail and streamlined body shape.

• Its sturdy hip bones and short legs with long, flattened, webbed fingers and toes.

• Its specialized teeth for eating only marine organisms.

• Its ability to breathe underwater for extended periods.

Which of the following is a shared characteristic between whales and hippopotamuses, suggesting a common ancestor?

• Both are primarily carnivorous and hunt fish.

• Both have a thick coat of fur for insulation.

• Both possess multi-chambered stomachs, which is unusual for meat-eating mammals.

• Both lay eggs on land and then return to the water.