(via Thai Panda)
I’m getting more than a little tired of the long-running wrangle on the wet ape hypothesis thread. I’m closing it and opening a new thread here, with a few rules:
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No more pointless dismissals of comments from either side as mere opinion or evidence-less, even if they are.
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Absolutely NO copy-pasting of arguments from other sites. If you’re not going to engage in conversation, but just want to unthinkingly recite rote claims from elsewhere, go away. That will be considered a bannable offense in this thread.
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If you want to reply to a previous comment, actually reply to it. That involves thinking about and addressing the points in that comment. That means actually backing up your claims with evidence.
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You’ve got one page of comments to do it all in. If this thread hits 500 comments, I’m simply closing it. You’re done.
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If you try to run out the clock and spew lots of itty-bitty repetitive posts, I will ban you.
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If you just snipe and run, I will delete your comment. So be substantive, or shut up.
OK? OK. Go to it.
I expect this thread will promptly die now that the obtuse and refractory proponents of paleontological nonsense are prohibited from regurgi-posting and are expected to actually have a dialog about the evidence. They may surprise me, but they probably won’t.
Besides, Space Ape Rules.
No David, they show the wear you would expect from someone who was fairly old. The gender markers are very clear. Female with a nice smile! ;)
Thank you, Gibb!
I’m surprised there’s so much sexual dimorphism in teeth – I’ve never noticed, and I’ve noticed huge amounts of individual variation.
I made teeth out of porcelain every work day for 12 years, several of them in the top cosmetic lab in the country. The differences are subtle to the eye, but absolutely necessary if you wish to make a prosthesis that matches the natural dentition perfectly. After you’ve made a few thousand of them, the differences are glaring.
For wear comparison see this roman woman.
The article is interesting too.
That’s some scary wear.
Apologies if this has been said already–I’ve been reading through the comments on the old thread into the 300s so far), and haven’t looked at this one yet. I do have something to (hopefully) add.
I’ve seen a lot of discussion of wading-as-origin-bipedalism and refutations thereof, also frequent swimming as a reason for hairlessness. I’d like to add a few datapoints to the discussion.
A quick search on Google shows me 4 different monkey species that swim: Japanese macaques (snow monkeys), proboscis monkeys, baboons, and Allens swamps monkeys. Reading the Wiki articles on these, I notice a few things:
–All are quite hairy, especially the macaques
–All use a quadrupedal gait for terrestrial locomotion.
Speaking for myself wrt moving in waist-deep or deeper water, if I’m not carrying something that needs to be kept dry, I’ll swim, not wade.
Also, are there any semi- or fully-aquatic species that do habitually move bipedally on land? I don’t know of any! The closest I know of would be polar bears, and they don’t travel far bipedally.
Just my two cents.
Even if the aquatic ape model was plausible, which there are a few good reasons to argue it isn’t, mere plausibility is not enough without positive evidence. How can someone have spent more than five minutes in a science class and not get that?
Quite apart from any safety issue, shellfish are far easier to spot when the tide goes out. Clams, for instance, as virtually impossible to spot when the tide is in; when it’s out it’s easy to spot their location. Crabs are both easier to spot and easier to catch.
Up island here at one of the parks, there’s a sign about tidal flats and all the animals that use them as food sources, headed with “When the tide is out, the table is set”.
I really appreciate the hard work people have put in here. I know little of the finer details in human evolution & this discussion has been fascinating. Yet I remain perplexed by AAH–particularly the absence of links to scientific papers & data. It appears that wetland ape hypothesis requires that 10 Mya or so, bipedalism developed via wading in seasonally flooded forests (existence of which seems questionable) or wetlands or riverbeds or something. Because doing this a few hours a year (no data to back up this claim either) would give some small, but significant advantage (What’s the advantage? Which is supported with what proof?). Said development could not have happened any other way or happened faster as a result leaving water-averse apes at a relative disadvantage.
Then 2Mya or so, our ancestor’s familiarity with water has brought them the beach wherein beachbum ape starts learning to swim & eat shellfish that expands the brain (faster than exclusively feasting on brains from terrestrial animals? And despite the noted lack of DHA?). How much of the time was sandy ape swimming at the coast rather than wandering the savannah?
So this sketch, leaves me woefully under-informed about what RA-CP actually entails : Would this not allow for some speciation to have happened in the mean time? Soggy ape differentiates from serengeti ape. Oceanic ape from continental ape? If wading is such an important difference, shouldn’t we have evidence of nonwading apes disappearing once wading has been selected for and conferred whatever advantages it did? (And how would we be able to recognize these differences?). Wouldn’t we see different traits in coastal & interior apes that would eventually be replaced by the superior oceanside apes? What data can you show us indicating the flow of peoples/traits from coastal & riverdwelling apes to “got my water at the watering hole and got out of Dodge”-apes?
And can you, Algis, provide evidence that other primates better adapted to wading are also better at swimming? And if not, what is it about human’s evolutionary history that allows wading to translate to swimming where it fails to do that in other animals? Besides looking at untrained chimps vs.untrained humans or computer modeled hominid swimmers, Algis really needs to define what it means to “swim better”? Is it about how long one can swim underwater or how far one can swim on the surface? Perhaps it is simply being able to cross a river deeper than chest height or head height? Instinctively flailing more effectively immediately prior to nearly drowning? It’s not enough to “swim better”, but to swim better via some specific mechanism (eg. arm strokes) allowing us to achieve some specific goal/advantage (pastures greener on the opposite side of the river; significantly more food reachable via swimming vs. wading or tidepooling). And to tie it into natural selection, you’ll need to show that the traits involved are genetic–not something that people learned to do. No relevant data from Algis, just a couple of observations about modern humans, suppositions about prehistoric life & lots of handwaving.
IANAPA but the following line of thought seems reasonable, based on the isotope and fosiil evidence. Feel free to poke holes in the idea.
If it is true that increased consumption of DHA made it possible to grow bigger brains, then the hominids who have the highest dietary RDA of antelope brains would logically be pregnant and lactating females.
*see comment 93 for all the supporting links
The paranthropus skull has the dental markers of a female hominid.
It is considered male based on a sagittal crest somewhat similar to male gorillas.
I posit it is a female skull that shows adaptations to meat eating.
I must confess to sharing one trait with Algis et al, mentioned somewhere up thread: I, too, share the unreasonable yet undying hope that people such as he will suddenly have an On The Road to the Damascus Labs moment and finally, FINALLY, understand what the scientific method is all about – and it ain’t mental masturbation.
I manage to control it most of the time, though. I only started three different comments here to that end before thinking better of it and not posting them.
That made me LOL (because http://en.wikipedia.org/wiki/Ayia_Napa).
Hey, we broke 500. It’s free-for-all, right? ;-)
Moreover, are there any facultative biped species that primarily switch to bipedal motion for wading, thus indicating its adaptive benefit for that purpose? Or do most species prefer to paddle on all fours instead?
Hi PZ, isn’t it time you stopped this vortex of repeated repeats?
Times up!
The No 1 creationist tactic – evidence denial.
So, guys, do think, on balance, looking at all the behavioural evidence available, that humans swim and dive better than chimps?
Astonished at the self-righteous unaninimity that group think sneering can generate.
Algis Kuliukas
I think Algis closing it out with a dose of his trademark projection is quite appropriate.
Assuming arguendo that humans swim and dive better than chimps, so what? One dubious claim made without evidence does not support your soggy ape conjecture (I won’t dignify your guess as a hypothesis).
Also humans are pretty poor swimmers compared to semi-aquatic animals like otters and beavers. That would argue against a semi-aquatic humanid ancestor. This point has been made several times but you’ve ignored it each time.
Weapons grade projection there, Algis. A creationist would be proud of your diligent repetitiveness!
Let me tell you a story.
My grandfather flew in Lancaster bombers in WW2. He was shot down over France, bailed out, and parachuted into the Channel. Never having learned to swim, he drowned. If he’d cradled a chimp as he parachuted, and let go once they hit the water, they both would both have drowned.
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Humans do not swim better than chimps, because neither species is inherently very good at swimming. Humans can learn to swim though, using adaptations that pre-date our LCA. We do not, however do so instictively, we do so because our (post-LCA) big brains and vocal abilities allow us to say things like “hey! take deep breaths and move your arms and legs like this!”, and do things like build swimming pools and train lines to coastal resorts.
I haven’t checked but if that’s Living Color, I claim my £10 prize.
*damn*
No £10 for me.
To take a page from your book and simply repeat myself: You have not successfully argued that your key piece of “evidence” is even true, yet alone significant, yet alone that it is proof of your hypothesis. Your only argument seems to have been to scoff and guffaw at the very idea that someone would disagree with the truth and/or relevance of “humans swim slightly less poorly than chimps.”
No, it is not obviously and unquestionable true that “humans swim slightly less poorly than chimps”. No, you haven’t presented any evidence to support your claim that it is true and you merely assert it. You take it as axiomatic and sneer at the gall of people who think that you should have actual scientific evidence to support scientific claims. I mean, for fuck’s sake, someone who was actually intellectually honest and serious about this thing could at least try to brainstorm a way that one could measure swimming ability and conduct an experiment to confirm or deny the claim if they couldn’t find actual evidence. But Algis couldn’t do even do that much. He was far more concerned about saying how he “totally isn’t anything at all like a creationist, seriously, you guys” and using every dishonest dodge, duck, dip, dive, and dodge he can muster from the creationist playbook to bother to actually substantiate the point, preferring to end this all by asserting it all over again. The most important line of “evidence” he can muster for his argument, and he still doesn’t have jack shit.
What, you figure if you keep repeating your observation long enough, I will suddenly believe it? HOW DO YOU KNOW? Do you have footage of chimps swimming? Anywhere? Seriously, how do you know this? Where is you evidence?
Astonished at the nonsequiturs from an alleged scienetist, with each one showing their idea is presuppositional, and not subject to scientific scrutiny. In other words, they are CRANKS/LOONS, just like creationists.
Interesting to note how often we get accused of thinking too similarly here. I mean, it could be that these are a bunch of different people coming to a similar conclusion based on different yet converging lines of evidence. Those “different people” being the accusers, of course. Not us. Never us. But that’s the puzzle: How is it that one can know that the pushers of “echo chamber!” memes are all independent thinkers that just happen to use similar language and express similar ideas, and yet one can also know that our common memes, similar language, and similar ideas are symptomatic of an “echo chamber” at work? I’ve always been fascinated by that.
I’ve also always been fascinated by idiots who push these memes when they clearly don’t understand what they are talking about. That is to say: Algis, “groupthink” is one fucking word. It is an actual term, with an actual definition, aside from just being something that all the Cool Kids sling around on the internet because it sounds fun and accusatory.
Can’t say. Comparing apples and oranges, as you well know. And your argument has been show repeatedly to be circular. Which means it is worthless to get you where you want to go. But then, that requires you to acknowledge you are wrong. Won’t happen, even though YOU ARE WRONG.
Algis:
Brown bears swim quite well. Do you have fossil evidence of an aquatic stage in their predecessors? Same for Polar Bears. Whales began as hoofed predators and did become fully aquatic. Are there species between the land predators and their antecedents? Some families of animals learn to swim and become fully aquatic. Why did Homo start down this path and then turn back?
I should be an easy one to convince. I’m an historian, not a biologist. Give me some evidence, actual evidence, and I might become a supporter.
Who’s the creationist who stops by every so often to repeat the mantra “how do you know?” The human/chimp swimming question is exactly the same. A presuppositional attempt to shut down inquiry and be agreed with. Our motto, question everybody, including AK. And he fails the questioning.
Before the thread closes, I’ll repeat my concern that nobody ever seem to clearly lay out a testable hypothesis. I find that frustrating, since it seems like everybody is discussing evidence for and against something that’s never clearly explained. How am I supposed to evaluate the evidence when it’s never clear what’s being proposed?
There have been a few hints during the thread, but never anything clear; what, when, where and how. I don’t think it’s unreasonable to expect the people defending the hypothesis to explain exactly what it is.
Scientifically, that is required. You have to allow yourself and your idea to be falsified by defining it rigorously enough for the evidence to either verify or refute the claims. But there is no way that AK will allow his idea to be falsified. Which is why it isn’t a hypothesis, and only an idea, and will remain only an idea.
Also deer!
And elk. (Paging Dr Seuss!)
And, oh wait, what was the point again?
Another thing Algis et al. have in common with creationists! The vagueness is intentional. It is their shield. It is the incredible dimness which lets their logical trainwrecks pass as amusement park rides. It is the fog which they reassure you is only temporarily hiding their mountains of evidence. It is the cover of darkness, under which they haul off goalposts. It is the murky waters which they dive under when a bombshell hits, and from which they emerge to have never seen or heard a thing. It is the opaque lens through which they see the world.
*dammit*
Moose.
But if they swim …
PZ:
“Man proposes, God disposes”
Man poops, gods are diapers.
Manpoops: Spin-off site for manboobz?
Now that we’re over 2000 posts…
Come a long way, haven’t we? Now I shall one-line.
Christian:
How is that “almost” literal? That doesn’t get you off the hook for using the word “literally” incorrectly.
Rey, perhaps Christian meant ‘littorally’. ;)
Humans swim better than chimps.
Why?
Because slightly wet ape ancestor.
How do you know that?
Because humans swim better than chimps.
Why?
Because slightly wet ape ancestor.
How do you know that?
Because humans swim better than chimps.
Why?
And the cycle goes on and on…
Bipedalism probably developed in trees, the way gibbons use it to walk on one branch while holding on to another. You can see that in Ardipithecus ramidus, is later than the last common ancestor of both chimps and humans, but must be similar. It was more bipedal than a chimp–their knuckle-walking habit is a later specialization. It’s a mistake to think that “primitive” means “more like chimpanzees.”
If aquatic proponents think merely “plausible” is sufficient, let me throw out another possibility:
The transition from facultative to obligate bipedalism was not due to specific selective pressures driving toward it, but a random event (say, a point mutation) resulted in an immediate switch to obligate bipedalism, with no transitional period. Once present, it conferred sufficient advantage to become fixed in the population, resulting in rapid speciation of the bipedal form.
Of course I have no direct support this… but I can go one better than the AAH by providing video evidence for the plausibility of my “Screw This, I’m Walking” Hypothesis. I present Natasha, the black macaque who, after recovering from serious illness, proceeded to permanently walk upright thereafter. The zoo vet considers the likely cause to be brain damage.
Now in Natasha’s case it is probably an injury, which would not be heritable. But if a similar shift in brain function were to occur due to a mutation, it could be passed onto offspring, resulting in a group of monkeys all walking upright for no special reason at all. The new freedom to take better advantage of hands for tool use could easily confer significant advantage in the long term, thus ensuring the new trait’s survival.
As genetic brain disorders are a demonstrable phenomenon, and there is a well-documented example of a living primate switching to bipedalism due to an apparently minor brain injury (no other faculties seem affected), I assert that the preponderance of evidence clearly supports STIW over AAH.
I thereby propose that my theory (which is mine) be forthwith adopted for immediate investigation by the scientific establishment.
[When the portcullis slams down on this sodden thread, will that littoraly be a watergate?]
While I think it could still be argued from the paper on human throwing that the mechanics of human shoulder anatomy implies that humans have a much greater potential for a stronger crawling stroke, I agree that that is insufficient to address human vs. chimpanzee swimming ability, since not all swimming requires such a stroke. Would chimps performing a front-limb paddle do as well or better than a human performing the same movements? Could chimps have their own optimal stroke and kick combination? The biomechanics of the more general question seem very unclear.
(As an aside, I note that the authors of the above paper did study chimp throwing, but they only used three individuals, two of whom seemed rather young (3 and 9 years). While chimpanzees do mature faster than humans, I think it would be more interesting, and perhaps more fair, to study more individuals, preferably some who are older and have greater physical coordination. On the downside, such a study might well also be more dangerous.)
I watched a couple of videos of “Cooper the Chimp” (first, second) in water, and also Suyia the Orangutan (here) as well.
I have to say, their performance as “swimmers” does indeed seem poor, in the sense of using any sort of stroke and kick combination to drive themselves forward any great distance. Suyia, in particular, actually seems to prefer getting rides from a human (who does seem to have very good swimming form, and swim fins).
Based on those videos, I would agree that the hominid apes portrayed do not swim as well as humans, and seem to prefer a more undirected splashing around in the water. There’s nothing wrong with that, of course, and I suspect that most humans would be doing pretty much the same. But could the apes learn to do better?
I have to wonder even more about the question of diving. Both the chimpanzee and the orangutan learned to hold their breath, and I really don’t know for how long they could make it last. The orangutan, particularly, did seem to be holding breath for quite a long time. Could they dive as well or better than an ordinary human, given that? I don’t think it could be ruled out.
Moving the topic back to human swimming: Another paper I found while searching for a PDF of Marean et al., Nature (2007), was this one:
O’Connor, S et al. Pelagic Fishing at 42,000 Years Before the Present. Science 334, 1117 (2011)
(PDF)
I would suggest that if people were going out in small vessels to fish for tuna and other deep-sea fish, they were probably pretty comfortable in the water, and I suspect swam very well indeed. Of course, there is no adaptationist argument from that; this was well after the evolution of modern humans. I’m just pushing back the date for the earliest probable appearance of that cultural behavior.
Hell, so do dogs and horses. Even cats swim better than untrained humans. Basically, humans are one of the few mammals that don’t swim instinctively, so claiming them as aquatic seems really fucking stupid.
To be fair, there’s bugger all that humans do instinctively any more. What remains seems to only be present at infancy (and many of those could be better classified as motor reflexes); things like suckling, grasping, and the aforementioned diving reflex.
Ironically for this discussion, I’d wager one of the few “proper” instinctive behaviours is walking. Babies have a stepping reflex, which shows the brain already sort of knows how to walk, even if the body isn’t developed enough to do it yet. It’s not exactly an experiment you could perform, but I suspect a human child would figure out how to walk on its own, if its survival needs could otherwise be met in the process. (Again, no biology/anthropology background so I may be totally wrong; let me know if so.)
The same doesn’t appear to be true for swimming — even dog-paddling isn’t the natural response for a human with no prior experience. Deep water exposure typically results in flailing wildly, followed by drowning.
Perhaps the rhythmic “kicking” of a young infant in water is the remnant of a swimming reflex we don’t have any more (but once did)… but it doesn’t help an infant survive in water so can’t lead to learning to swim on its own, and it doesn’t last long enough into adulthood to help learn later.
Stray thought: When my cousin was a tiny kid (not sure how young, but young), I remember playing with him. He was sort of standing on my lap (with my support, because he couldn’t really walk yet) and he would stretch and bend his legs over and over, in a sort of kicking motion.
This was nowhere near water, so it makes me wonder if it’s really a swimming reflex or just a generic movement that happens to look a bit like swimming.
All five of mine made a stepping motion (alternate legs) when held upright (body and head supported by adult hands) for the first few weeks after birth. As did all mygrandchildren.
As they got bigger, heavier and stronger and could hold their heads up and support their weight on their legs, with the adult merely providing balance rather than complete support, the movement changed to an up-and-down bobbing motion caused by flexing their knees, hips and ankles but keeping their feet firmly on whatever surface they were standing on.
Newborn babies also alternate their legs when crying and waving their limbs around, whereas older babies are more likely to kick both legs simultaneously.
I don’t think that the stages babies goes through as they gradually gain control of their limbs indicate the locomotive stages that our ancient forbears went through, tempting an idea though that may be. All my descendants, as babies, tried to pull themselves into a standing position as soon as they had the strength and co-ordination; but before they had proper balance. Then they would stand there, both feet firmly planted and both hands firmly gripping whatever they had used to haul themselves upright, grinning hugely – until they realised that they dare not move a single limb and were, therefore, quite stuck. At which point they would yell for rescue.
The next escape strategy was that they learned that, thanks to their padded-by-nappies bottoms, they could safely let go with their hands and fall into a sitting postion and crawl off.
As they gained confidence, they learned that they could move one hand to another grasping point and then move a leg, too. Eventually they were cruising around the furniture, dropping to crawl whenever they met a gap until they got strong enough to hurl themselves to the next piece with a free step. Shortly after that, anywhere between 12-22 months, they were walking independantly (some have connective tissue disorders, giving them hyper-flexible joints, which delayed walking; one didn’t learn to walk until the pædiatrician ordered ankle boots).
For an intelligent and curious animal, having their hands free to carry things (having first plucked them from somewhere out of reach of an animal on all fours – there’s a reason precious stuff moves higher and higher in a home!) is an enormous bonus. Dogs carry the kill bag to the den in their stomachs, and the pack members who stayed behind have to be content with regurgitated food. Or they have to keep returning to it, hoping that other animals haven’t eaten it all in the meantime. Human hunters can carry far more of a kill or than would fit in their stomachs, and the rest of the tribe gets fresh food too.
Bipedalism conferred a huge advantage to a plains-dwelling animal. According to everything that I have read so far, it is very likely that it was a development from the bipedalism already being practised by brachiators. Adding a wading stage is an unnecessary extra step and, firstly, explains nothing that isn’t explained by what is already known and, secondly, raises questions (e.g. about risks and diet) that are answered in the negative by all the evidence so far collected.
My offerings to Tpyos! =^_^=
There should be a gap between ‘my’ and ‘grandchildren’, ‘the stages babies goes through’ should be ‘the stages babies go through’ and ‘bag to the den’ should be ‘back to the den’.
All hail Tpyos!
It seems that most feral children do not walk bipedally, although the reasons aren’t necessarily easy to identify. Some have had contact with dogs or other animals, and so copy those, and it’s difficult to tell if a child had any disabilities prior to being abandoned.
@Algis #515
Algis, you idiot, no one ever disputed this. What we do dispute is that the reason we swim and dive better than apes is because we had an aquatic period in our evolutionary history. You are completely unable to point to any specific adaptations which facultate better swimming and wading that you can actually say with any certainty evolved because of an aquatic evolutionary period! Your entire argument is merely a repitition of “We swim better than monkeys!”. Fuck, when asked for proof of the periodically flooding gallery forests on which your hypothesis relys, you provided one paper which suggested Paranthropus habitat always contained wetlands, one paper that directly contradicted your theory, one that said Hominids evolved in “well watered forests”, and three that were completely irrelevant. You have proven precisely fuck all, and frankly I tire of your circular arguments.
@PZ
I thought we only got 500 comments for this? Because you know this idiot is just going to keep shouting “We swim better than monkeys! Why won’t anyone agree with me! Waaaaaah!!!!!!!” until you shut him up.
I’m curious*, jefrir. How many instances of feral children are there, that there can be a ‘most’?
*And horrified.
FacultateFacilitateAnteprepro #532
Thread won!
Well, you topped 500 late at night on a day I was sick. No fair!
Thread closing…NOW.