Q:   How can you determine the way an animal looked millions of years ago just by using its fossils. How much is guess work?
— Akeisha
A:   The fossils can tell us a great deal about what an animal looked like, how it moved, what it ate, and even how it may of behaved. The bones give clues to how the muscles attached. From that data, you can get an idea of what it looked like when fleshed out. The bones show how the skeleton fits together and you can see how the animal stood or swam. As there are a number of animals that exist today that may have similar looking bones, it stands to reason that the fossil species may have been living in a similar manner.

You can then use the modern species as a model to predict how the fossil may have looked. Except in cases where the animal was fast frozen, you can not tell what color it was or if it had long hair, but we can tell a lot about the animal. Tracks have been used to estimate the walking speed of dinosaurs. Radioactive isotopes have been employed to determine if an animal lived in saltwater or freshwater.

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Q:   Did our ancestors briefly flirt with becoming aquatic? I look at the way we are built: we are essentially hairless like whales; some of our fellow humans have large deposits of fat; and we can dive in water. When I see films in which people are diving in the water and seals are hunting in the water, I see very similar behavior in the way we and they move. Finally, do any apes dive and eat seafood?
— Don
A:   There was a theory, called the Aquatic Ape Hypothesis, that was popularized in a book by Elaine Morgan titled, "The Aquatic Ape." It considered the very idea you asked about. As we have similarities with other aquatic mammals such as naked skin, a layer of fat under our skin, a large brain, and can swim, it may be that humans were starting to become aquatic. Unfortunately, the fossils do not indicate that we were becoming a primate-dolphin. It is more likely that in our more recent history, we moved along the sea edge or places where there was water and started to forage on fish, clams, snails, and crustaceans. Why we have a naked skin is still a matter of some debate.

Apes do not dive. They cannot swim and will drown if placed in water. Some monkeys in Japan do go in water and forage along the coast for food, but they do not swim.

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