Talk:Aquatic ape hypothesis/Archive 4

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Criticisms of the criticism

Don't get me wrong, I love people offering alternate points of view, and considering I had never heard of this theory before yesterday, when I read the criticisms as a scientist, they were very weak and fallacious. I'm going to change a lot of them, and here's why:

Nakedness

Differences is human hair is somewhat trivial. Human hair has more in common with land mammals than aquatic animals, but this does not disprove the theory as the contention is that humans were land animals living in a semi-aquatic environment, not that they were aquatic animals themselves. Be mindful that there are also land mammals that have varying purposes for “hair”, or keratin, which include hooves and horns.

Breathing

The length of time an animal can hold its breath is usually related to the amount of time would have been optimal to secure the underwater food or avoid predators based on principles of evolution. Had humans been in a semi-aquatic environment, it may not have been necessary to dive deeply to locate a food source and thus not being able to hold one's breath for 40 minutes is hardly proof that they didn't have to hold their breath for food.

The use of “dog” as a non-aquatic example is flawed, as dogs do swim and have been known to dive underwater for various reasons and would then have a similar reason to control their breathing.

Fat

It should be important to distinguish that fat has different forms and purposes. Brown fat and white fat are the two main types that animals possess. Human babies have large amounts of brown fat to generate heat, but adults have larger amounts of white fat which insulates and produces energy for the muscles. High amounts of white fat is more common among aquatic mammals than land mammals. Blubber is another fat entirely. This criticism needs to articulate itself a lot better to be considered legitimate.

Additionally, rural people generally have more fat than urban people (France[1], Nigeria[2], Tunisia[3], India[4], Canada[www.statcan.ca/english/freepub/21-006-XIE/21-006-XIE2003003.pdf]), with the exception of the United States [5]. However some countries, including Japan, find rural dwellers are also affected by more variables[6].

Childbirth

This is a problematic argument as it is nearly impossible to comment on the problems associated with size of the infants head due to brain size as we don’t have anything to compare it to. Compared to early hominids or other animals? It’s not a sensical argument. Also, the narrowing of the hips is a bit of a misnomer. In some ways, the pelvis did become slimmer to contain the internal organs much like a bucket, but the main and most life threatening problem is that a baby’s head must pass the pelvic opening and the tailbone at the same time in humans as a result of being bipedal, while quadripedal animals give birth first by passing the pelvic opening, and then the tailbone at different stages. Oh, and what did this have to do with proving or disproving the theory at all?

As for a “typical method of childbirth”, different cultures all over the world birth in different ways. I have not read any studies which have examined the ways in which these positions are advantageous to the birthing process. Many websites cite squatting, sitting, and on hands and knees as being advantageous positions, but delivering a baby while standing upright is not one of them. There is some interesting information on labour positions [7]. The position for birthing may not be a good argument for or against, as the advantage of being a semi-aquatic creature is that just because a hominid ancestor spent large amounts of time in the water, doesn't mean they would necessarily birth there. Salmon are known to leave their usual habitat in saltwater to go spawn in freshwater. Animals are versatile.

That being said, water births appear to be the most beneficial to a mother, and a lesser extent, the baby. Increased buouyancy helps mothers produce additional hormones like oxytocin which aid in birthing and breastfeeding. Babies are in little danger of drowning and do not take their first breath until they make contact with air and continue receive oxygen through the umbilical cord for several minutes until this happens.


Nutrition

Omega-3 is actually a difficult fatty acid to obtain in proper quantities when balanced with Omega-6, since terrestrial Omega-3 is found in few plants and in grass-fed, not grain-fed, animals (which is not how we typically feed our livestock in North America). The criticism is additionally flawed as the theory is about how humans developed, not how humans are able to survive now. The Omega-3 article attributes the need for Omega-3 to humans living in coastal areas.

Swimming

Swimming well is not a completely necessary trait for an animal in a semi-aquatic environment. Being able to paddle and hold one’s breath from a young age is a good indicator that it was needed at some point in evolution. Stating that children will drown unattended is a fallacial argument because young of current tree-dwelling animals fall out of trees when unattended. Expecting young to have all of the skills as an adult is not a good argument.

In modern humans, many people drown as a result of panic and not paying intention to instincts. This is also why humans who are great swimmers also find themselves drowning in 4 feet of water when they could easily stand up. Natural abilities for most humans include floating and paddling and this is actually indicative of having evolved to spend some significant time around water.

  • An Error in counterclaims: One pro for swimming is that it is the easiest excercise on the joints, as compared to walking, running, jumping, etc... yet, the con is "Water-based exercise results in greater levels of body fat" which has nothing to do with the original pro, and is simply there (I assume) because of seeing the word "excercise".

This also brings up a second problem, that the word "excercise" in the pro should be changed to "physical activity" Nnnudibranch (talk) 08:51, 3 January 2008 (UTC)

The bigger problem is that the entire claim is unsourced and original research. WLU (talk) 12:31, 3 January 2008 (UTC)

Traits atypical of aquatic and semi-aquatic mammals

This is a fallacial argument. The theory never proposes that humans are are aquatic mammals, but that they were land mammals living in a semi-aquatic environment and developed some traits similar to those of aquatic animals. That being said, large ears, long limbs, and long cranial hair are all good examples of criticisms in this vein. They do not disprove, but they do raise a good question.

Broad, rounded shoulders is a function of the limbs and is akin to saying “and elbows, fingers, wrists and fingernails.” It is not a separate proof.

Large breasts is also not acceptable, because while it is not shared with aquatic mammals, it is also not shared with land mammals. The nearest animal to this is probably the gorilla whose breasts grow postpartum, but then disappear when done breastfeeding. Most land mammals have small teats.

Current lack of aquatic behavior is also not valid as much as saying birds never evolved through a stage shared with lizards because they no longer have teeth and eat meat. There are other land mammals, like the Elephant, who no longer have aquatic behavior either. Or don't we? Humans still build up major cities around waterways and bodies of water.

Recent Fossil Finds

Hominid evolution did not occur in a straight line, and in fact there were often several hominid species living at the same time at different points, and no evidence for other gaps. Orrorin tugenensis does not “fill a gap” and disprove that humans never lived in a semi-aquatic environment, espcially because according to the wiki article, researchers are still trying to determine whether O. tugenensis or Australopithecus afarensis is the most direct ancestor to modern man, and also as such, does not actually fill missing gaps in a timeline, but proposes an additional brach in hominids.

Vagueness

This is a great example of criticism.


So, honestly, most of these criticisms are not very good, though some are valid. I encourage everyone to examine things with a critical mind. In many cases, what was said made sense, but had no basis to refute the theory presented because in many cases as it was arguing the wrong point.

As an aside, humans in utero have tails and gills at different points of their development (ontogeny recapitulates phylogeny), but these is just a function of developing our most recent adaptations last. For reference, this does not support the theory. --Waterspyder 19:24, 24 February 2007 (UTC)

  • A seperate idea/ sort of fitting into this subsection though: In general, I was confused as to why a lot of the criticism shuts down ideas based on humans not being fully this, or fully that; when the theory in general seems to say that humans were in the process of evolving to aquatic areas... and a lot of the counter-arguments seem to argue against a fully aquatic human. At this point the article has been gutted of the debate form it was in, and has lost a lot of material, but if it is to be brought back, this should be taken into consideration. —Preceding unsigned comment added by Nnnudibranch (talk • contribs) 20:31, 3 January 2008 (UTC)

both hypothysis

could parts from both hypothesis' be true, humans do like to move around abit, we could have learned a few bits in the water and a few in the savannah, maybe savannah man and water man bred together

Humans are naturally a pretty strong opportunist. There's no doubt that groups of humans after modern humans evolved traveled along the beach sides and ate a large amount of fish and seafood. Upwards of 30% of the diet in areas. The same is true today. However, most of the traits prescribed to AAH are absurd and more likely adaptations to as actual anthropologists suggests to distance running, walking, bipedalism, fire, or as a secondary byproduct to our large brains. Some proponents like Algis Kuliukas (personal correspondence) try to leverage "humans ate fish" into some larger grand theory of water. Some people today live by the sea and fish and some people live inland. However all of that is already a part of mainstream anthropological thought and doesn't require a new theory which starts from the hypothesis and looks for evidence (which is why it reportedly happens sometime between 4 million years ago and a few thousand), that isn't the way science works. Humans ate fish... grand theory of human evolution and dozens of books are a must for this stunning revelation. Tat 06:31, 4 November 2007 (UTC)
This is a typical misrepresentation of the idea. Tatarize clearly doesn't like the idea so he/she feels compelled to attack and distort it at every opportunity. No-one has ever argued that humans are not opportunists or that they were totally reliant on aquatic foods. The question that Hardy asked was "Was Man More Aquatic in the Past?" - the word "more" is key. Now more is a relative term, it means that since the LCA with the chimps we have been exposed to greater pressure of selection from moving through water (wading, swimming and diving) than their lineage has. That's all. It doesn't mean that we were aquatic in the sense that a seal or a dolphin is aquatic. That's why the label is wrong and that's why so many people have just missed the point. It should be called "Waterside hypotheses (plural because there are more than one) of human evolution".
Humans swim better than the apes. If you were to compare any two other animal taxa in a given substrate and determine that one was better than the other then, if you are a Darwinist, you'd conclude that natural selection was the explanation. Since the LCA of the two, one species has been exposed to greater selection to move through that medium than the other. This is a ubiquitous explanation for all of the billions of permutations except, it seems, one: When humans are compared to apes in water. Then, suddenly the rules change and, apparently, the explanation is anything BUT natural selection. We're smarter than they are. There are lots of things we can do better than them: play musical instruments, ride bikes, climb mountains etc. We're opportunists. Why not just go with the usual Darwinian explanation: since the LCA our ancestors have been more aquatic than their's?
AlgisKuliukas (talk) 02:10, 18 December 2007 (UTC)
Again, I must point to WP:RS, WP:V, WP:OR and now I add to this, no personal attacks. Tat disagrees with the hypothesis, that's not a reason to make it personal. Cite sources, as they are far more convincing, and a statement backed by a reliable source pretty much can not be challenged or removed by other editors because they don't like it. Though its interpretation can be bickered about and debated. WLU (talk) 15:11, 18 December 2007 (UTC)
I apologise for my "personal attack" on Tartarize. AlgisKuliukas (talk) 10:12, 19 December 2007 (UTC)
Yeah, it's not really a personal attack (you could always strike it out, thus, or delete it outright, or refactor it to a more neutral statement) but it does make the paragraph unduly pointed at another editor; when pages like this one (fringe topics) don't get a lot of traffic, the talk pages usually get a lot of abuse heaped on them just 'cause there's less need to be civil 'cause there's no-one to talk to. Anyway, hopefully Tat will come back to the page and we can work on a version of the article that represents a consensus of believers and skeptics. I'll drop him a line on his talk page. WLU (talk) 12:19, 19 December 2007 (UTC)

Sea of Afar

I created this section. I had to create the Wiki entry on the Sea Of Afar to do it. It that becomes deleted it will become meaningless but see the Afar Depression which was once flooded and underwater. SmokeyTheCat 14:19, 30 March 2007 (UTC)

The section didn't have any actual evidence in it, or citations - it looks like WP:OR to me. Also, even logically it doesn't make sense - early humans or protohumans were not locked into specific geographic locations. If an area got wet, they would move and therefore not evolve to suit the environment. If it dried, they would follow the water. Anyway, a citation would be useful. WLU 22:23, 30 March 2007 (UTC)
I agree that the section needs evidence before being included. But I do want to point out that emigration was not necessarily an option. If the Red Sea suddenly burst into the Afar Depression, then the lucky few who didn't drown may have found themselves on an island. They could have tried to get off the island... or they could have found that suddenly they have an abundant seafood source and no competition for resources, so... why leave? — Epastore 15:40, 31 March 2007 (UTC)
A definite possibility, but without a source, is original research. Also, it would have to be a very large island, would dramatically reduce the breeding population, tremendous inbreeding; I'm guessing there would be some genetic evidence of such a powerful population bottleneck. Anyway, once someone puts in a reference, it could be replaced but right now it's too dodgy in my mind. We'll see what Smokey has to say as it is his section. WLU 16:11, 31 March 2007 (UTC)
No argument on the OR... though I do think there is a cite out there somewhere. But to the point of the stranded-on-an-island idea... it could be a large island, containing a significant population of the primates in question. And if the event were 7 million years ago, it wouldn't be a population bottleneck in homo sapiens, it would be an event in primates overall. Our first ancestor to diverge from the chimps is believed to have originated... around 7 million years ago: orrorin tugenensis. See also: Timeline of human evolution. — Epastore 17:18, 31 March 2007 (UTC)
It'll have to wait until the source then. Note that I changed the indent on the talk page - I use the second system discussed in layout. WLU 21:55, 31 March 2007 (UTC)
A link is :- http://www.exn.ca/Stories/2000/06/29/58.asp You can find several more by searching under 'Sea of Afar'. Definitely not OR at least not by me. Apes *can* swim if forced to so our ancestors wouldn't have drowned. I don't like to revert if I am in a minority of one but this seems like persuasive evidence to me.SmokeyTheCat 10:32, 2 April 2007 (UTC)
Feel free to re-ad it with a citation, though that one doesn't seem appropriate for the page. If you've got a better one with references, I'd be happier. WLU 15:37, 2 April 2007 (UTC)
"Sea of Afar" produces exactly 66 Google hits. Not exactly what I would call persuasive. JPotter 22:15, 2 April 2007 (UTC)

I've put back in my 5 shillings worth, with a link this time. Like I said not OR by me. It's still a relatively new idea tho' which explains why there are so few Google hits. Still no reason why Wiki can't be cutting edge. The link is - inevitably - Elaine Morgan SmokeyTheCat 12:19, 10 April 2007 (UTC)

Swimming children

Under "Childbirth" the article staes the children can "swim" from birth. The use of quotes suggests some doubt on this, so where is the source of the information? If it is undisputed, why is it quoted? Or is this swimming different from what we recognise as swimming? Can we have a reference, please?!

Children tend to hold their breath and go through some vaguely crawl like motions while underwater. This isn't swimming and could never keep the infants head above water. Calling it swimming makes it seem like there's some there there. You can check youtube for a number of videos, they move their arms and legs, we move our arms and legs when we swim, therefore, babies must swim. Yeah, the quotes are there because without them you need to say that they babies when shoved underwater tend to move their limbs. Tat 21:35, 29 August 2007 (UTC)

Aquatic mammals are all testicond

The principle argument of the aquatic ape hypothesis seems to be that humans have aquatic origins because they are largely hairless. However, hairlessness is not a precondition to aquatic or semi-aquatic life histories. It cannot even be claimed that hairlessness is a general trait of aquatic mammals as there are a large number of examples of aquatic mammals that are furred (Bmearns this includes the majority of seals and sea lions, which are highly adapted to the aquatic environment and not recent entrants to the water). In fact, aquatic mammals of about human size and smaller are almost all furred (there are a few small dolphins and porpoises). In contrast, a trait that is shared by all aquatic and semi-aquatic mammals of all size classes whether they are furred or hairless is that they are testicond (i.e. their testicles are kept within the abdominal cavity or inguinal canal), yet humans are not testicond. If humans have aquatic or semi-aquatic origins why do we not have the one trait that is shared by all mammals adapted for life in water? HMRaven 07:12, 9 June 2007 (UTC)

That's a good point. I am generally a proponent of the AAH but I don't have an answer to that one. Have to give it some thought SmokeyTheCat  •TALK• 15:56, 25 June 2007 (UTC)
Not sure if this is relevant, but there is a condition in which testicles "fail to descend". There are also cases in which the testicles "retreat" into the body cavity (i.e. in the cold, during coitus). Do other land animals share these characteristics? If not, then these could be argued to be remnants of a time when we were testicond. Just speculation, of course. Aelffin 20:36, 5 July 2007 (UTC)
The condition in which testicles fail to descend is a developmental abnormaility not a hangover from our evolutionary past, I believe it occurs in other mammals. Testicles do retreat as you say, but they should not retreat inside the body cavity. That would also be abnormal.HMRaven 03:22, 18 September 2007 (UTC)
Proboscis monkeys are not testicond, and they're probably the most aquatic primate other than humans. kwami 23:36, 31 October 2007 (UTC)
2 objections that come to mind: firstly, where is the reference that all aquatic and semi-aquatic creatures are testicond? Dolphins, yes, but creatures such as beavers? Maybe they are testicond while swimming but not while on land. I would need to see some verifiable sources to be convinced of this point.
Secondly, it's not necessary for modern humans to have retained all aquatic features for AAH to be true. Lets remember that the contention is between some aquatic influence (as AAH proposes), and exclusive land evolution as maintained by the sceptic side. It's undoubtedly true that humans have many features not typical of aquatic or semi-aquatic creatures - and also many features not typical of land animals. This is exactly what would be predicted by AAH, given the postulated sequence of a relatively short aquatic period, followed by a much longer period (some millions of years) with a reduced aquatic element. --Antony (talk) 11:39, 27 December 2007 (UTC)
I'll venture a third one - the page is already stuffed to the gills with unreferenced original research claims and criticisms. Before this can go on the page, it really needs to be sourced. Otherwise it's another example of wikipedia being co-opted into a fora for the Aquatic ape hypothesis and it's detractors. WLU (talk) 14:19, 27 December 2007 (UTC)

Feet

Unlike most apes human feet do not have an opposable toe. A primate that treads water would have no need for an opposable toe. Apes often sit when they use their feet to hold things; this would not work in water. Also the arched shape of the feet makes humans more suitable for walking in mud or the sandy bottoms of rivers, lakes, and the ocean[citation needed]. The skin on human feet is very soft and vulnerable to sharp rocks and sticks that might litter the ground in a forest or savannah.


...

Any evidence that AAH proponents have made this silly argument? Tat 05:18, 31 August 2007 (UTC)


AAH is one of my secret delights, but the distinctiveness of human feet seems more likely to be an adaptation to bipedal terrestrial life rather than bipedal semi-aquatic life. I would imagine that feet with no opposable toe are much more efficient for extended bipedal travel over land than feet with such a toe, and that an opposable toe would be incredibly advantageous for a semi-aquatic species. All of the other extant apes have opposable toes as an adaptation for aboreal or semi-aboreal lifestyles. Animal species adapted to ongoing overland travel have dense, relatively fused feet. An opposable toe would make the feet very useful for finding and grasping bottom-dwelling prey while keeping the head above water, and in your "treading water" example a modern foot would be useless, but a foot with an opposable toe could manipulate underwater objects. The modern human foot may possibly be more efficient for swimming, but I don't think that any AAH proponent contends that these postulated lifestyles involved locomotion that was meaningfully rapid in comparison with other aquatic organisms. --Raphite 05:37, 3 November 2007 (UTC)

Morgan at least suspects that our feet are adapted primarily for a terrestrial environment, not an aquatic one. If we did go from arboreal to aquatic to terrestrial, you'd expect adaptations to all three environments, with the earlier ones coopted by the latter ones. kwami 07:44, 3 November 2007 (UTC)

Newer Format

To address the problems with the old format, giving the arguments and then way later establishing the counter claims where there were better terrestrial theories or falsehoods in the argument presented. This format allows the counter claims to be quickly and easy presented. This gives a reader a clear view of the arguments used by proponents of AAH without providing false information. Arguments do not need to be removed because they are false or dishonest, simply addressing those points which are misrepresented. Also, the counter claims to the arguments weren't properly "criticisms". Tat 07:19, 31 August 2007 (UTC)

Finger and toe webbing

If you look at a human hand you can see that vestigal webbing still exists between our fingers. Indeed to this day one in hundred humans are born with partially webbed toes. How to explain this without a period in our evolutionary past spent in water? Anyone mind if I add this to the article?  SmokeyTheCat  •TALK• 16:31, 29 October 2007 (UTC)

If you're going to cite it as evidence, make sure there's an actual citation. Speaking of citations, I've went through the intro and added actual inline citations rather than author/year, and attached it to specific statements. I then removed the citations from the references section. Also changed section title capitalizations and removed a couple entries that looked like pure OR and had no citations. This is not the place to debate the theory, so any criticisms and counterclaims need to be referenced. I trimmed the citations in the intro somewhat so only a representative sample remain, rather than have 15 citations in the first paragraph alone for criticism/support/neutral. Looks cleaner. WLU 17:38, 29 October 2007 (UTC)

Arguments section

The 'arguments' section, and I use that term loosely, has virtually no citations. I realize that there is a long references section, but it's much better to deal with if there's citations for specific statements. I'm going through the page now, if anyone can review the page later and attach specific citations to specific statements, you'd be doing the page a huge favour. WLU 20:14, 31 October 2007 (UTC)

I've re-written some sections, but I'm out of time. I'll try to continue later on. Unfortunately this leaves the article as somewhat of a hybrid, so if anyone else wishes to continue, feel free. WLU 21:03, 31 October 2007 (UTC)

monkeys swimming underwater

Allen's Swamp Monkeys, as their name suggests, are somewhat aquatic. Saw a young one at the San Diego Zoo, where they're raised in an enclosure with otters, play chase an otter about 10m, tumble with it a couple times, then swim the 10m back, all under water, only to be pulled out by an older monkey. It looked like it could do at least 30m underwater on one breath if it wanted to. There used to be a troop of guenons in the enclosure, and I never saw any of them swimming. Suggests that perhaps breath control is an adaptation to an aquatic environment. kwami 23:32, 31 October 2007 (UTC)

Unfortunately without a discussion in a reliable source, it's primary source and not a published one. Though it's a good idea if you can find a discussion of said species. WLU 23:40, 31 October 2007 (UTC)
Wasn't planning on adding it to the article, just thought I'd mention it here for those who are interested. There is some stuff about them in back issues of ZooNooz, since I think the SD Zoo staff were surprised at how well the two species got on together, but I don't know if anything is ever mentioned about swimming underwater. kwami 05:06, 1 November 2007 (UTC)