Were we aquatic creatures before we moved on to dry land, even while we were still mammals?

Question

Homo sapien is the only terrestrial mammal which has a descended larynx. Only whales sealions seals and the like have the descended larynx, and they all dive for long periods beneath the waves, and incidentally, while this larynx is of no advantage to us landlubbers, it is distinctly advantageous to all aquatic mammals with regard to controlled breathing. I ask myself why is it only us humans out of all the primates that have this characteristic ?

Answer 1

The lower larynx in humans developed (it is thought) as our ability to use language evolved. Having the larynx further down, helps to prevent us choking. It is probably unlikely that we would have such a complex language system if our larynx were further up.

Answer 2

I cannot agree with the water born development of the human laryngeal development. That would appear far too early.

I favor the assumption that geophysical upsurging in East Africa about 3.5 to 4 million years ago killed the jungle there, forced our ancestors out of the disappearing trees,on to the ground thereby forcing our ancestors to walk upright.

This posture eventually allowed for more skeletal room for an elongated larynx and eventually more complicated sounds which eventually developed into a rudimentary language and eventually Shakespeare.

What about that idea?

Answer 3

Apparently, its because we have evolved [yes, there's that wonderful word again] if you start here and track backwards you can always find a theory that fits... but, you try doing it the other way.  Where will we be and what will we end up like???

Answer 4

We have vestigial webbing between ours fingers - the hairs on our backs follow the flow that water would make - our upright gait may stem from water supporting us and being able to keep our heads above water in the shallows. .

Answer 5

yes we were in the water at one point, dolphins are mammals - theres the proof... i saw summit about the sea creatures coming out of water -  newts/frogs

Answer 6

I disagree with the assumption that we were once aquatic. We are more closely related to the chimpanzee, not only genetically, but physically. If we were once aquatic, that would require us to gain aquatically beneficial characteristics, such as, as you suggest, lower larynx, plus webbing, waterproof skin like the whales etc, and then lose them most of them, and regain the appearance of a chimp. I don't think that evolution works that way. Once changes have occurred, and been lost, it is not likely that they would have been regained, as another mutation may have occurred, taking us in a different direction.

On the same tack, since we are related to the chimps, we would have had to become aquatic, and then land-based, in the 7 million years since we had a common ancestor, which does not seem to be enough time for such a major move.

The descended larynx would seem to be an advantage for breathing, but it is also an advantage in communication. The whales use it for both. Clearly, to me, in humans it has developed for the communication advantage alone. Fossils of early hominids show no tendency to aquatic life, or transitional aquatic/land based life. Only we humans have descended larynx, among the primates, because it was advantageous for us, with higher intellect, to us to develop it, so it was naturally selected for. It was advantageous for whales and seals to have it for the advantage it gave to underwater swimming. Similar development, different advantage.

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Answer 7

i dont think we were ever aquatic

Answer 8

. Interesting statement about the larnyx, but your Question, by it's phraseologly, answer your question:

"Were we aquatic creatures before we moved on to dry land", well, you can't 'move' onto dry land without being aquatic first.

Answer 9

We also have..

Near neutral bouyancy, unlike other apes, allowing us to swim and dive. Other apes sink like a rock in water.

Vestigial webbing between our digits.

A diving reflex from birth (slowed heartbeat and respiration.)

A swimming reflex if dropped in water as a newborn.

Blubber, other apes don't gain body fat the same way as humans.

Directional growth for our hair (streamlining).

Very little body hair, so little that our skin had to turn black to protect us, while our nearest relatives have pink skin.

A high requirement for the omega three oils mostly found in marine life forms (shellfish would probably have been the main source).

I'm on board with the aquatic ape theory, but it would probably have been really early on in evolution (pre Homo).

Answer 10

u have to remember even this is just a theory,  we really dont know where we came from.

i like to learn too, but u have to admit the similaritys between science and religion, alot of its faith.

explore all things, then make up ur own mind.