Evolution Of Whales

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This assignment will look at the fossil record of whales as an example of empirical evidence for evolution and is inspired by the article “Land-living ancestors of whales” from the “Berkeley: History of Evolutionary Thought” resource for Module 1.

There are two extant groups of whales; odontocetes (toothed whales) and mysticetes (baleen whales) and both share many features with all other mammals: they generate heat and regulate their internal temperature. The females bear live young and produce milk in mammary glands to feed them. Although they do not have hair on their bodies some adult whales have sensory bristles around their mouths and there is a stage when the foetus has hair.

Along with these general mammal characteristics whales
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They still had hindlimbs but these were tiny and the pelvis was detached from the vertebral column so they are unlikely to have been weight bearing. Figure 4 shows their skeleton. Figure 4. Skeleton of Basilosaurus; the tiny hind limb is shown enlarged. Adapted from National Geographic's The evolution of whales by Douglas H. Chadwick, Shawn Gould and Robert Clark Re-illustrated for public access distribution by Sharon Mooney ©2006. Open source licence CC ASA 2.5 as viewed at
The Dorudontids probably gave rise to the Basilosaurids and the two families of extant cetaceans. They had similar proportions to the modern cetaceans, as shown in figure 5, and were completely independent of freshwater.
Figure 5. Skeleton of Dorudon atrox; © Philip D. Gingerich 1996, available online on his web site as viewed at
The vestigial hindlimbs are good evidence for evolution. If the whale had been designed they wouldn’t be there. (sorry I have run out of time).
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