Evolution Flashcards
What is phylogeny?
Study of relatedness among species. Going back in time to find a common ancestor.
What did whales evolve from?
Hooved animals.
What animal is the starting point for whale species?
Pachyaena
What is the Pachyaena?
Hyianna like animals, walked shorelines to catch prey. Earliest point of whale teeth. Related to an ungulate.
What did Pachyaena evolve to?
Ambulocetus.
What are the characteristics of the Ambulocetus?
Semi-aquatic, first swimmer. Skeleton changes becoming more adapted for swimming, shorter front legs, and longer hind. Becoming more streamline.
How did the Ambulocetus skull change?
Became more elongated, for hiding in the water. Also bitting power increases.
What did the Ambulocetus evolve into?
Robhocetus.
What are the characteristics of Robhocetus?
Limbs become shorter. The skeleton becomes more fused, hind legs are easier to stretch back from swimming. The skull becomes more elongated.
What did Robhocetus evolve to?
Basilosaurus.
What are the characteristics of the Basilosaurus?
Major leap from Robhocetus, very fusiform. Has from flippers, no more limbs for land.
What did Basilosaurus evolve to?
Dorudon.
What are the characteristics of Dorudo?
Very similar to Basilosuarus, but smaller due to the availability of food. Have spear-shaped teeth.
What did Dorudon evolve to?
Brygmophyster.
What are the characteristics of the Brygomphyster?
Like a sperm whale. Has spiked teeth to eat squids. Uses echolocation from melon. First species with the mechanism for echolocation.
