Aquatic Ape Hypothesis

[Trap Queen Voxxy]

I just heard of this hypothesis today from my roommate and I was curious as to what some more science savvy members think. I'm currently watching the BBC documentary and I think it's fascinating and I would like to get others opinions or theories on the subject. So, do you think it's possibly that instead of our ancestors making their way from the trees to the open plains of the savannah instead where aquatic? Further, do you think this theory is credible or plausible or do you think it's ridiculous and laughable? If the latter, please explain why.

For those unfamiliar here's the wiki link (http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis) and I posted part 1 of the documentary below.

liuE4bkNly0

[Anarcho-Brocialist]

Everyone's ancestors are aquatic, the first single celled organisms (cyano bacteria) were inhabiting the oceans before they came on land.

bipedialism is used by supporters of the theory about the advantages of humans in the water.

I think it's plausible because we haven't found the missing link, also, we still have a lot more to discover. Albeit I must note, I still support the originals claims of evolution over AAH.

[PC LOAD LETTER]

Somebody asked this in /r/askscience a while back (a heavily moderated section of Reddit for those unfamiliar with it)

http://www.reddit.com/r/askscience/comments/p4ddp/what_are_your_thoughts_on_the_aquatic_ape/



The Aquatic Ape Hypothesis (not a theory!) does explain several human tendencies rather neatly and elegantly, this is definitely true. However, what it mainly lacks compared to the regular view on human evolution the basis of science itself; empirical evidence. We can trace human evolution pretty much all the way back to our early shared ancestor with chimpanzees through fossils, who all seemed to live in savannah-like regions. One explanation for this is that the aquatic populations have left fossils mainly in regions that are currently under sea level and thus haven't been found yet. This does explain why there hasn't been found any evidence, but the fact remains there hasn't been found any evidence. And although alternative hypotheses must always be encouraged in science, evidence must be provided to be generally accepted.
Additionally, the Aquatic Ape Hypothesis is a good example of an explanation that seems elegant and neat at first, but contains a good deal of inconsistensies on further examination. I'll take an example: human body hair. At first, the aquatic ape seems a good explanation for this - we all know hippopotamidae, dolphins and whales have little body hair, so it seems to make sense that a semi-aquatic lifestyle would prompt the developing human species to lose their body hair. However, we're comparing ourselved to huge animals as whales and hippopotamidae (remember that they have very large amounts of body fat to compensate for their loss of fur) or fully aquatic animals such as dolphins and whales (remember that a fully aquatic lifestyle puts far greater selection on any hydrodynamic quality than a semi-aquatic lifestyle). It'd make a lot more sense to look at semi-aquatic animals comparable to human size. What we find is not a loss of hair at all - we find very dense, insulating and evenly spread body hair, a near polar opposite to human body hair. So, how so we explain human body hair in the conventional theory? Using another evolutionary mechanic that is intensely abundant in higher lifeforms: sexual selection! We all know that chimpanzees love to groom eachother. Similarly in humans, the shape and grooming of body hair is intensely important to how we are perceived in society. As you can see, human body hair can be explained just as well by conventional theory as by the Aquatic Ape Hypothesis, maybe even better.
tl;dr There's a lot to be said for and against the Aquatic Ape Hypothesis, but it's not a better or worse explanation of human evolution than the conventional theory and most importantly lacks empirical evidence to support its claims. Always remember that science does not rely on pretty explanations but rather on what can be emperically proven.




I'm with you until you proposed that human body hair was lost through sexual selection.
There may well be sexual selection against body hair today, but there is no reason to presume our ancestors cared about it.
A better hypothesis is that we lost body hair in order to lose heat faster. This is also why we sweat so much and why our feet are so unique among animals- there were strong selection pressures involved in increasing our ability to run long distances in hot weather.
When modern hunter gatherers hunt, they don't always use ranged weapons. Generally, all that is needed is to chase the animal until it collapses from exhaustion and overheating. They hunt at the time of day when the temperature peaks because this is when the human advantage over other animals peak. No other animal can run as far for long distances as we do, and we rarely overheat while running thanks to our sweat glands... so unless you are able to somehow fly or hide yourself, if a physically fit human starts chasing you you are pretty much doomed. As predators, hominids were likely much more dangerous than reptiles and big cats, because they could never be outrun.

Also plays into domestication of wolves into dogs ... they're great distance runners, too, and could help our primitive selves chase down prey; but that's a slightly different discussion

[Koba Junior]

My understanding is that there isn't enough evidence for this hypothesis for it to be considered very solid. I could be wrong, though.

[Trap Queen Voxxy]

@CanisLupus;

Thanks for your post mate, I'll review it properly and then respond.


My understanding is that there isn't enough evidence for this hypothesis for it to be considered very solid. I could be wrong, though.

I'm currently trying to research this as much as possible so I can attempt to play devil's advocate on here. I think it would be interesting and I will post more about this later once I've collected my data.

Keep the posts coming, glad to see others are interested.

[Anarcho-Brocialist]

@CanisLupus;

Thanks for your post mate, I'll review it properly and then respond.



I'm currently trying to research this as much as possible so I can attempt to play devil's advocate on here. I think it would be interesting and I will post more about this later once I've collected my data.

Keep the posts coming, glad to see others are interested.
The composition of the body is really the point of this hypothesis. It doesn't present former homo species ancestors as proof of its hypothesis compared to the original theory, yet it instead contrasts humans with 'tree-hanging' primates.

In example would be; we have better blood circulation in water, swimming causes less pain to our backs and hips, we have less body hair than primates, which makes it easier to swim etc. Based on those conclusions, and the parameters of our bodies composition, and natural ability to remain buoyant, we must come from the water. This, like said before, uses the contrasts between human and ape in aquatic conditions.

Like I said before, I've looked into the hypothesis a while back, and it may be true, but I'm sticking with the original theory of evolution.

[Revolution starts with U]

I think it's plausible because we haven't found the missing link, also, we still have a lot more to discover. Albeit I must note, I still support the originals claims of evolution over AAH.
Homo Erectus, habbilis, and ergaster aren't enough? What about Australopithecus? What missing link would suffice? :lol:


The composition of the body is really the point of this hypothesis. It doesn't present former homo species ancestors as proof of its hypothesis compared to the original theory, yet it instead contrasts humans with 'tree-hanging' primates.

In example would be; we have better blood circulation in water, swimming causes less pain to our backs and hips, we have less body hair than primates, which makes it easier to swim etc. Based on those conclusions, and the parameters of our bodies composition, and natural ability to remain buoyant, we must come from the water. This, like said before, uses the contrasts between human and ape in aquatic conditions.

Like I said before, I've looked into the hypothesis a while back, and it may be true, but I'm sticking with the original theory of evolution.

It also explains why we have blubber. As said above, there's really no empirical evidence for it. But I wouldn't be surprised were it true.

[Trap Queen Voxxy]

Homo Erectus, habbilis, and ergaster aren't enough? What about Australopithecus? What missing link would suffice? :lol:

Every time I hear debates about the missing link I think of that Futurama episode where Dr. Farnsworth went all down the evolutionary chain.

[Anarcho-Brocialist]

Homo Erectus, habbilis, and ergaster aren't enough? What about Australopithecus? What missing link would suffice? :lol:



It also explains why we have blubber. As said above, there's really no empirical evidence for it. But I wouldn't be surprised were it true.
It has been debated if Homo Erectus and Homo ergaster are different. I should have worded my comment differently; to we have not found all of the missing fossils. And claiming a missing link would mean I disregarded the findings of Homo Erectus, which is correct and I was wrong xD.

[Book O'Dead]

Everyone knows about the amazing sea monkeys!

www.sea-monkey.com

[Permanent Revolutionary]

There really isn't enough evidence to support this hypothesis (yet), but it is an interesting idea.
Bluber or fat in humans can't really be used to support this hypothesis, because other great apes also have fat deposits.
One should also note, that the main porponent of this idea has strong feminist seniments. I'm not anti-feminist, but this may also have an effect on her scientific ideas, although "hairlessness" is a good argument for the hypothesis, I think.

[Kronsteen]

It's one of those hypotheses which provides a solution to a few minor mysteries in human biology...at the expense of creating a lot of huge mysteries.

One of which is: Exactly when were humans supposed to have been sea-dwelling anthropoids? There's no gap in the evolutionary record large enough to hold an 'aquatic phase'.

The 'hairlessness' argument is that: Humans are relatively hairless. Hairlessness makes swimming easier. Therefore the only possible reason to be hairless is to make swimming easier.

There are hairless species of dogs and cats. Are these found in countries with lots of lakes and an ocean? No. But they are found in countries where heat retention isn't a big issue.

On the fat issue, it's true that humans are the fattest of the primates. But fat is used to store energy as well as help us float. So we may float better than gorillas, but we're also better at storing energy.

If the extra fat were there to help us float, then the aquatic ape would have to be one where the periods of life when we're least able to put on weight would be the periods we'd spend on dry land. Thus the aquatic ape would be born in the sea, and spend its adolescence and early adulthood on land, going back in middle age.

[Kronsteen]

bipedialism is used by supporters of the theory about the advantages of humans in the water.

How exactly does having two legs with modified hands at the end constitute an advantage over a single fin, for swimming?


I think it's plausible because we haven't found the missing link

The missing link is creationist propaganda. Modern humans are one point on an evolutionary line, and the most recent human fossil is the previous point. But what about all the points in between? They're missing.

Until we find a fossil to plug the gap. Then there's a new missing link - the one between modern humans and the new fossil.

It's one of the ways creationists can always pretend there's doubt about evolutuon.

[Lenina Rosenweg]

My understanding is that the aquatic ape hypothesis-that our apelike ancestors where on the way to becoming fully aquatic- had some popularity in the 50s but since then has been pretty much debunked.

The AAH would explain bipedalism, hairlessness and the fact that a few people are born with webbed toes and fingers.

The idea has been kicking around for a while.It was made famous by a British marine biologist, Alistair Hardy and popularized by a Welsh writer Elaine Morgan in the 1970s.The theory is intriguing but generally not popular today.I don't think there is evidence that the area in East Africa where we are believed to have evolved experienced dramatic flooding.Also the AAH is considered overly convoluted as an explanation for hairlessness, etc.Occam's Razor.

http://en.wikipedia.org/wiki/Aquatic_ape_hypothesis

Also, I think homo ergaster and homo erecturs are basically the same thing. In the Ancestor's Tale Richard Dawkins likes to use his own somewhat eccentric terminology. He prefers to use ergaster when most people would use erectus.

[Trap Queen Voxxy]

I think Morgan's point of sexism could potentially hold some weight considering how when it was brought up paleoecological data suggested that the area that makes up what we now know as the Afar depression was, at the time of Australopithecus would have been around, was indeed subject to massive sea flooding was simply disregarded as being circumstantial and not necessarily a possible indicator that humans could have perhaps had aquatic origins.

I also think that it's a fair charge considering Hardy and Morgan's hypotheses have been outright rejected which, traditional evolutionary views which at given times have rested on same lack of evidence or circumstantial or essentially on equal footing as AAH have received more attention and thus more efforts and funding in terms of research.

While reading the myriad of the critiques of AAH, they seem rather simplistic, if almost to simplistic and (while I could be wrong) seem to rest on possible logical fallacies and straw-men based upon rather uninformed or rather zealot arguments provided by some of those whom support AAH. As for the lack fossil evidences for the hypothesis I would argue that further research is necessary to determine whether it's true or not and would point out it wasn't so long ago that evolution rested on shoddy evidence and data itself.

I mean, let's look at how research commonly functions. First, to begin to research you need funding and funding comes from investors or organizations in which are interested in the pursuit of X anthropologist, archaeologist, geologist, etc. theories, ideas and research. Basically, the capitalist system is tied in with scientific research. Now, what is the nature of the capitalist system? It's incredibly hierarchical and patriarchal and virtually everything is directed into preserving and maintaining this. What am I getting at? If we have a hypothesis of which goes against scientific orthodoxy and the commonly held beliefs of the system and of which is immediately discredited it's very unlikely that it would receive any serious funding for long term serious research in the field and elsewhere, which is to say, at least theoretically that AAH can neither be proven or disproven until serious research has occurred and that we must also take into account the technology of the day. I mean Australopithecus was an amazing find which changed the time map of what we thought our evolutionary chain looked like.

[Revolution starts with U]

A tad off topic but... one of my profs in uni was partial to the "monogamous" explanation for bipedalism :lol:

[Yazman]

Everyone's ancestors are aquatic, the first single celled organisms (cyano bacteria) were inhabiting the oceans before they came on land.

bipedialism is used by supporters of the theory about the advantages of humans in the water.

I think it's plausible because we haven't found the missing link, also, we still have a lot more to discover. Albeit I must note, I still support the originals claims of evolution over AAH.

There's no such thing as "the missing link". It's a myth creationists use to try and discredit evolutionary biology and examination of the myth reveals a lack of understanding as to how evolution works. It appears to refer to "chains" of organisms, with supposedly "lower" organisms being lower on the "chain" than "advanced" organisms. Evolution is shifts in frequency of genes over long periods of time. If you absolutely MUST visualise it, then imagine it as a very long continnum, a fine gradient, not a chain. We can see it working today where people are generally taller in the anglosphere than they were 500 years ago. The idea of a "missing link" is just something creationists jump at, they take arbitrary points in time and say, "where's the link between the two?" because bones and corpses deterioriate over time, so naturally there's gaps in the fossil record, leading some people to develop a misunderstanding of how things work.