Of Beavers and Other Aquatic Mammals

I find the transition of animals from terrestrial to aquatic to be absolutely fascinating. At first it seems impossible - how could a land mammal evolve into a massive blue whale? Far from impossible, this has actually happened more than once - in at least 4 independent occasions! Whales evolved from hooved, wolf-like predators. Dewgongs and Manatees are most closely related to elephants. Pinnipeds(seals) are most closely related to Bears, and evolved from some carnivorous proto-bear. Lastly, otters have evolved from from proto-weasels - while remaining nearly physiologically identitcal to weasels!

Beavers, a semi-aquatic rodent, are also way sweet. They are second only to humans in the extensiveness of their terra-forming. They live in complex lodges, in ponds tailored to their liking. A lot of what they do is very instinctual - running water triggers an instinct to create dams, which can also be stimulted by the mere sound of running water - experimenters have found that they will pile sticks around speakers emitting said sounds. Man, I wish I was a beaver.

Here is an artists rendition of some proto-whales:


pakicetus.


ambulocetus.


kutchicetus.


rodhocetus.


basilosuarus(this name is a misnomer, as the fossils were originally/erroneously thought to belong to an aquatic reptile).


I think the rest of the steps can be easily imagined.