Additional interesting bits of human physiology used in the argument for the AAT are:
- The pattern of hair on our backs. Like all mammals, humans are covered with short hair. The hair on our backs lays down and towards the center in a streamlined way that would theoretically facilitate swimming.
- Noses. Compared to all other primates our noses are very long and rigid. Our nostrils point down as opposed to gorillas and chimps whose nostrils are almost flush with the face. This is quite useful when swimming for preventing water from getting into the respiratory system.
- Geological evidence. At around the time that Homo sapiens became a species in their own right, sea levels appear to have been higher than they are now in the areas where human fossil evidence is being found.
- Swimming primates. Most primates cannot swim and do not like water. (If I remember correctly, chimps sink like rocks.) One exception is the Probosis monkey which has been seen wading bipedally in waist-deep water. Probosis monkeys have developed longer legs than many primates, and their proportions appear closer to humans than most other monkeys. Humans, however, love water. Look at the modern world and how cities and vacation spots are arranged. Few seem interested in touring savannahs, but we flock to beaches.
- Voluntary breath control. Primates are physiologically unable to hold their breath. However, humans have developed the ability to regulate their own breathing, a necessity for diving.
- Vocalization. The wide range of sounds we can make is due to the orientation of our larnyx. We share this feature with only a few other animals: the dugong, sea lion, and walrus.
- Our obsession with sharks. A casual examination of the animals that seem to interest us today reveals a disproportionate fascination with sharks. If we have an aquatic history, then sharks would have been our dominant predator. It would make sense for us to want to know as much as possible about them. We don't seem to have the same degree of fear and curiosity towards savannah predators like lions.
Note: this last is my own personal observation, and carries only the weight of an untrained pseudo-scientist.
Noted human zoologist Desmond Morris has been known to support aspects of aquatic ape theory as well. Although he has a certain amount of notoriety, he has spent most of his life studying the human species as an animal.