Amen-Moses

I just did an experiment with my family (my youngest son at 6, my daughter at 11 and my ex-wife), my son could close his nostrils fully after about 5 minutes of practicing, my daughter could not initially overcome the urge to breath in whilst doing so but after a few minutes could close to about 50%, my ex wife couldn't get the hang of it at all and only made funny faces (which at least gave us a laugh).

My son is an excellent natural swimmer, my daughter is also a good swimmer but won't go underwater. My ex-wife is terrified of water and has never learned to swim.

The way in which I showed my daughter to do it was to pout with the top lip only whilst breathing in through the nose, the nostrils automatically closes when you do this but open again as soon as you stop breathing in. So I told her to initally breath in through her nose then try to hold the nostrils closed whilst finishing the in breath through the mouth. After a few minutes she could hold her nostrils closed for a few seconds at a time.

My other son who is 16 can not only hold is nostrils closed for as long as he wants (he does it to make silly voices as he is a budding actor) but can also wiggle his ears and wobble his eyeballs (not sure how he learned to do that!) at the same time - really weird!

Amen-Moses

pz

I have no idea what you are talking about here. In marine mammals, it is quite unambiguous what we're talking about when we say they can close their nostrils -- they have muscular control that allows them to physically pinch the nostrils shut.

People lack those muscles (at least, all the people I've seen, and all the people I've seen described in the anatomy texts...although, admittedly, this has never been a topic of interest in anatomy texts). I can well imagine that someone might be able to crinkle up their face enough to close off the nostrils, but it's nothing like the effortless move that a seal or otter can make, and doesn't sound particularly practical for someone who is swimming.

Duvenoy

Not at all. The point is that this ability is strictly individual conditioning. I can no longer do it - I was disabled out of the service in 1967. But anyone who wants to work at it can aquire the skill, whatever their race, creed or color.

The fishing polar bear was using a technique often observed in brown and Kodiac bears. I don't think that blacks, not known for fishing, do it. As for pandas (are they bears? Seems I've read that they are closer to raccoons), while I've never seen it, I'd bet morgage payment that they too, can swim. Honey bears? Common names suck. I've heard this name applied to kinkajous, of all things. But, if it's a bear, it swims. Even the odd, little sun bear swims and seems to enjoy it. I've seen this at a zoo.

Swimming 21 miles in fridged water? Would that be the English Channel gluttons for punishment? I seem to recall that many have had to be fished out due to hyperthermia, even though they were coated with grease (yuk).

However, there is an SA tribe I read about years ago that could withstand fridged tempertures for extended periods. Again and yet again, conditioning; adapting to an environment. What our YEC friends might call micro-evolution, although I find that a bit of a streach.

Armadillos, three species, if I remember right, are mammals, are they not? As are brown and black rats (excellent swimmers), raccoons (don't try to tell me these are even semi aquatic. They merely take advantage of another of many food sources), and so on.

Having thought about it, I'll give you the polar bear. Everything about them, from their huge feet to their specialized fur is adapted for fridged water. I'll also give you the capybara, that huge rodent of the Amazon. Although most of their time is spent ashore, it is well adapted to the water.

However, none of this is any sort of evidence for AAH. Fun to talk about, though.

Tell ya what, show me a hominid fossil with (I've forgotten the Latin and am too lazy to look it up) the spine joining the skull in such a way that the creature is not swimming all but face down. Then I might give AAH some consideration.

doov

PS: When we did a free dive, usually in search of spiny lobsters, we'd hypervenalate for a minute or so, then fill the lungs with all we could get in there, stop breathing, and head for the bottom. Sometines, we'd have trouble equalizing the pressure in our ears. If the tube was badly clogged, sniffing a little salt water up the nose would often clear it. Could this be a genetic memory from our aquatic past? Not very damn' likely! Them ears wasn't built fer divin'.

Amen-Moses

Well I can certainly do it with ease, the muscles appear to be connected just above the upper lip and the other end just about half way up the side of the nostril (just below where my glasses sit) and all it requires is a little squeeze to close my nostrils. It is far easier to do it underwater and I used to swim several lengths of the pool with them closed.

If you flare your nostrils (you can do that can't you?) whilst using the same muscles you get an effect similar to the Chimp grin where the upper lip curls slightly but not many humans can actually get the lip to completely curl unlike the lower lip.

Amen-Moses

The Lone Ranger

I've read a fair amount on the Aquatic Ape Hypothesis. So far, I haven't read anything to convince me that it's anything other than an interesting hypothesis.


For what it's worth, weasels, stoats, martins, and otters are all mustelids -- very close relatives. Otters are basically just big aquatic weasels.

Cheers,

Michael

RufusAtticus

Note of interest:

Pandas are bears.

Waits LP, Sullivan J, O'Brien SJ, Ward RH. Rapid radiation events in the family Ursidae indicated by likelihood phylogenetic estimation from multiple fragments of mtDNA. Mol Phylogenet Evol 1999 Oct;13(1):82-92

Abstract:

Duvenoy

Thanks Rufus.

Being more interested in Reptilia, I haven't been keeping up on Panda research. Too cute and cuddly for my tastes, I guess.

Always good to learn a little more, but the info flows so fast these days that you have to look quick.

doov

atrahasis

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Ok guys i give up!!!!!!
Somebody said a real man knows when to walk away!

The reason being that i have read quite a number of AAT critics and found it to be nothing but trash.... Seanie can continue from here...

But i will still maintain that man might have had to go into aquatic life a few million years ago if the greate flood really happened.....But note..Just as any other animal would if their is greate flood today...

Let the wise teach the mystery to the wise

seanie

Hey I'm continuing nothing. I'll just get stomped on.

I wasn't trying to promote AAT it was just that some of the criticisms seemed misplaced. They reminded me of the old anti-evolution chestnut "What good is half an eye?"

OK we might be clumsy and poorly adapted compared to other aquatic mammals. But at some point Dolphins weren't suited to an aquatic environment either (although we wouldn't call them Dolphins at that point).

So judging the suitability of humans in direct comparison to other aquatic mammals seems unfair (although examining what is useful in those mammals is relevant).

You'd really have to make a determination about the differences between current humans and the common ancestor of chimps and humans and whether those differences would've conferred an advantage on us in a semi-aquatic environment.

Not necessarily a big advantage. There's no point in pointing out things that would've been even more advantageous. They're neither here nor there. It's about being better in relation to our ancestor not other aquatic mammals.

However even if you could establish that we had adaptations that were compararatively beneficial in such an environment it doesn't necessarily follow that they were adaptations in response to such an environment. They could be incidental. A by-product of different selection pressures.

That appears to be the consensus. Other theories more plausibly accounts for the differences we see.

[edited in a vain atempt to cover up my total lack of knowledge]

[ September 16, 2002: Message edited by: seanie ]</p>

Stephen T-B

Things have moved on and Ergaster probably ism’t around any more, but I don’t know why he answered a question asked of Vorsigan arising from his statement: “No scientist I know of attributes all of humankind's unique features to evolution in a savannah biome. They all have much richer and more diverse views of the possibilities.”
I wanted to know more information about these “richer and more diverse views of the possibilities.” Ergaster didn’t provide an answer, he merely suggested that I’m a lazy journo who distorts the facts I’m given, implying it wasn’t worth giving me any?
I don’t know how I asked for that attack. I simply wanted to know. I’m not responsible for how other journalists behave; I am responsible for how I behave and in all my career I have never been asked to shave back the truth in order to please my editor or make a story stronger or squeeze it into a small space.
This thread has come up with some very interesting ideas, but those who reject the AAT as trash don’t seem to have trashed it so well that its advocates have had to change their minds.
This may be a case of people believing what they want to believe and it being impossible to persuade them that they are wrong. But I ask again: “Why am I wrong to think that something distinctive occurred in our ancestry which altered our appearance so dramatically from that of our cousins which also evolved in Africa?”
I made the point, which seemed to have been misunderstood, that although kangeroos are bi-pedal, that was a way of delivering economy and speed of locomotion, which clearly did not apply to our ancestors, for while we may be quite good in water (and rather good at swimming under water, too,) we are slower than most four-footed mammals when it comes to running.
Getting on our back legs to scan the horizon seems a poor explanation for bi-pedalism, as demonstrated by the meercats which stand up and then go back to all fours.
Bi-pedalism, I think, is far more interesting than our loss of a pelt - as it has been pointed out, we are a hairy species, and where it grows thickest has a sexual relationship - because the foot is our most specialist piece of equipment, and its use involved significant adoptions in terms of posture.
Did using tools give the upright walker an advantage?
Was being upright an advantage when a group of proto-humans were collaborating in a hunt?
Was it an advantage for a shore-dwelling species which had discovered that food was to be had in the sea and so took to wading?
Are we in the position of waiting for more evidence, or is there a view that “well, that’s the way it is, and it’s not very interesting.”
If so, I beg to differ. I think it is very interesting. I think it crucial to our understanding of how we became what we are.