Jim Moore's "AAT Sink or Swim?" Web Site
What Is the Aquatic Ape Theory (AAT)?


In this page Jim Moore does something that few have tried to do and deserves some credit for it: He tries to define what the so-called "Aquatic Ape Theory" (AAT) actually is. Clearly, if anyone is going to evaluate it, it would be a good idea to first define what it is you are trying to evaluate. Unfortunately very few people have tried to do this and even the AAH proponents themselves seem to have been neglectful in this regard. Sir Alister Hardy FRS was never very precise about it and, following in his footsteps, neither was Elaine Morgan. So, credit to Jim Moore here for setting out, right at the beginning, to attempt to define the hypothesis. But... how did he do? Actually, not very well.

Unfortunately the definition is only a small part of this page and he repeats the mistakes of the first page defining it as 'hypothesising that humans went through an aquatic stage in our evolution'. Not every form of the AAH proposes that it was a distinct stage and there's the thorny question of how aquatic is 'aquatic'. It might seem picky but it could be argued that Moore is being sloppy here using the terms 'humans' as opposed to 'human ancestors,' and 'aquatic' as opposed to 'more aquatic' or 'semi-aquatic' (although one can imagine how he'd react if Morgan had done something similar.) If it's not sloppiness then one is left with the conclusion that he's understood the AAH to be far more than Hardy ever claimed (more aquatic than an ape but less than an otter) and far more aquatic than in the definition I would adopt. (That water acted as an agency of selection in human evolution more than in great ape evolution.) So, the point is that Moore has mischaracterised and therefore not correctly defined the the hypothesis he is critiquing. - Not a good start.

He gives a small and incomplete historical treatment of the AAH and then begins to attack Elaine Morgan for her scholarliness. I find that although it is true that her earlier works are far from good examples of how to cite references, they are probably no worse than some other popular science books, such as Desmond Morris' 'The Naked Ape' - one of the books which inspired her to write about this hypothesis. Moore is very ungenerous about her last work which is a well referenced as any similar popular science book. Worst of all, his criticisms against Morgan's scholarliness quickly lose their effectiveness with every unsubstantiated claim he makes. Not a single allegation so for in this web site has a carefully referenced, and page numbered citation to back it up. Double standards here, Jim.

On this page he also claims to review the methods of the AAH but, I am afraid, grossly misrepresents them. For example, he claims that AAH proponents use a straw man argument when referring to the savannah hypothesis when aridity has been a large part of the assumption behind models on human evolution for most of the last century. To make matters worse, most of his arguments on this page use precisely the same tactics - the straw merman in ridiculing an interpreted version of the AAH which was never promoted. Double standards here too.

What is the Aquatic Ape Theory (AAT)?
Moore defines the hypothesis more fully here as this:

"The Aquatic Ape Theory (aka AAT or AAH) hypothesizes that humans went through an aquatic stage in our evolution, during the transition from the last common ancestor we shared with apes (LCA) to hominids. It claims that certain features are seen in human anatomy and physiology which are only seen in humans and aquatic animals and that these constitute proof that our ape ancestors went through an aquatic phase in their transition from ape to hominid. Using the principle of convergent evolution, it says that life in an aquatic environment explains these features, and that a transition from ape to hominid in a non-aquatic environment cannot."

Let's take this definition a piece at a time.

The first sentence more or less repeats the earlier definition. I want to focus in on two key terms in that sentence: the idea of the distinct aquatic stage and, again, the use of the term 'aquatic'.

Firstly, the phase. Hardy did indeed hypothesise a distinct phase for this to have happenned. He wrote "The students of the fossil record have for so long been perturbed by the apparent sudden appearance of Man. Where are the fossils that linked the Hominoidae with their more ape-like ancestors? ... The gap... Is it possible that the gap is due to the period when Man struggled and died in the sea?  It is in the gap of some ten million years or more, between Proconsul and Australopithecus that I suppose Man to have been cradled by the sea." Hardy (1960:p645.) Morgan, following in Hardy's footsteps, also made this kind of assumption of a distinct phase that happenned somewhere between the split with the great apes and the time of Homo.

As the two key proponents of the hypothesis make it clear that they do argue for a distinct phase it is fair and reasonable that Jim Moore defines it that way. However, I think it should have also been made clear that not all proponents of an AAH-like model for human evolution share that view. Verhaegen et al (2002), Ellis (e.g. 1993) and Crawford & Marsh (1991:pp154-187) have all espoused models of human evolution that may be broadly classed under the 'aquatic' umbrella, but which do not need or suggest any such distinct phase but rather a general trend towards greater aquaticism in the hominid line than the ape line. More on this point later, but I think any review of the AAH should include such details.

Now the term 'aquatic'. Jim Moore makes no real attempt to define this 'aquatic stage' and leaves it very much open to interpretation. Taken literally, one could forgive a reader for understanding that 'aquatic' actually meant aquatic in the real sense of the word. That is, that this hypothesis was actually postulating that man's ancestors had, at one time, been aquatic like, for example, a dolphin is aquatic. Clearly, if that were the case, the hypothesis could be laughed off with consummate ease and with little need to put together a 25-page web site. So, we must assume that, as Moore did not laugh it off so easily, that he understood that the hypothesis was not arguing for anything like that.

Hardy actually made the degree of aquaticism he was postulating quite clear, although Moore (and very few others) ever seem to pick up on it. He wrote "It may be objected that children have to be taught to swim; but the same is true of young otters, and I should regard them as more aquatic than Man has been." (Hardy 1960:p643). Hardy's title was, of course, "Was Man More (my emphasis) Aquatic in the Past?" and this strongly implies that the degree of aquaticism he has in mind is not only more than we are today but, by implication, more than the great apes' ancestors were too. So, we can neatly define the degree of aquaticism as espoused by Hardy as this:

'More aquatic than an ape, but less aquatic than an otter.'

This should really be part of the definition in my view, but we can forgive Moore for not being so precise.

His next sentence perhaps puts the AAH case a little too strongly but does, correctly, reflect the main body of evidence for the hypothesis which Hardy originally cited - human physiological analogies with aquatic mammals, such as whales, walruses and porpoises. His use of the word 'proof' is a little loaded, of course. Hardy never hinted any such proof was forthcoming in his very modest original paper. It ended, note, "My thesis is, of course, only a speculation - an hypothesis to be discussed and tested against further lines of evidence. Such ideas are useful only if they stimulate fresh inquiries which may bring us nearer the truth." Hardy (1960:p645). This is hardly claiming any sort of proof.

Perhaps it would have been better, and more accurate, to characterise the argument thus:

Analogies of human physiology, such as nakedness and a sub-cutaneous fat layer, which are most commonly found in aquatic mammals, led Hardy to hypothesise that perhaps such traits might be explained by human ancestors having a greater association with an aquatic lifestyle than they have today.

It should also be noted that Verhaegen et al (2002) promote a model of evolution which postulates that all the African great apes also evolved from a stock of hominoids which were already more aquatic than apes are today. Their 'aquarboreal' model suggests that the last common ancestor of African apes and humans were mangrove wetland inhabiting climbing-wading apes. Therefore Moore's definition should, technically, be refined a little to encompass that.

The final sentence, about convergent evolution, is fair in my opinion although I am a little nervous when I read phrases like 'life in an aquatic environment'. Does he mean to suggest that the AAH is proposing our ancestors lived out at sea? If so, that is clearly not the case. Remember Hardy's line was 'more aquatic than an ape, but less than an otter.' As long as that is understood I think it is correct to portray the AAH in the terms Moore has laid out and certainly proponents of the AAH would argue that living by the water's edge and therefore moving through water regularly explains these features far better and more parsimoniously than do the non-aquatic models.

Who thought up the Aquatic Ape Theory?
The next section starts with a good historical summary of the AAH although he fails to mention that Max Westenh
öffer, a German scientist, was thinking along similar lines independently when he published his book 'Der Eigenweg des Menschen" ("The path to Man") in 1942 as was the Italian scientist Sera.

The section has eight paragraphs, four of which are specifically about Elaine Morgan, who he describes, fairly, as "at the time, an Oxford grad in English and a TV scriptwriter". Considering that she is the most prolific adherent of the AAH this balance is also fair although, almost from the start, Moore cannot resist sticking in the boot. Describing Morgan's first, and best selling book 'Descent of Woman' (Morgan 1972) he writes "I wouldn't call it particularly female-oriented, but Morgan presented it as "the" alternative to what she then called "The Mighty Hunter" theory." Moore doesn't back this claim up with any reference, however. Considering that his promise, on the first page, that "You won't find those problems [difficulties in finding citations] here" has now already been broken at least twice, it does not bode well.

He then launches an attack (again not backed up by any evidence as yet) on Morgan's next three books, arguing that they are not properly cited. Moore then makes this, much more serious, allegation: "Morgan also has a creative hand when it comes to quotations, especially quoting out of context in the manner of creationists." Again, there is no sign yet of any evidence,  quotation or anything but his word, to back this up. He claims that Morgan's "habit of rarely giving sources for her quotes, and even more rarely giving page numbers.... is counter to scientific and journalistic practice" but having just picked up a few other popular science books on my shelf and done a quick survey I find that Morgan's books are just as well referenced as they are.

Quick 'pop survey' or Popular Science Book Referencing
'The Naked Ape' by Desmond Morris (1967) has just two and a half pages of references at the back and a three and a half page bibliography. His citation of Hardy's "ingenious theory" (Morris 1967:p29), for example, is not referenced at all forcing one to look in the Bibliography.

'The Origin of Humankind' by Richard Leakey (1994) has eight and a half pages of references and bibliography combined. By means of a sample I read the start of Chapter 4. It was almost three pages before there was a citation, a quote from Darwin's Descent of Man. Leakey 1994:p78)  No page reference was given in the text, or in the references at the back of the book. Following on from this was another reference, this time to an essay by Timothy Perper and Carmel Schrire. (Leakey 1994:p78) No references to that one at all. And then another, on the same page, for John Robinson's (1963) 'classic paper' which is properly referenced at the back. So, in this admittedly tiny sample, one out of three.

'Ever Since Darwin' by Stephen Jay Gould (1977) has a five page bibliography. Again, if I pick a chapter out of the middle of the book at random (Chapter 13 The Pentagon of Life, p113-125) and look for his standards we find them to be flawless. Two citations, both perfectly referenced with page numbers and all.

'The Language Instinct' by Steven Pinker (1994) has a twenty-four page set of references and all the sample pages I scanned appeared to be excellently referenced.

Unweaving the Rainbow' by Richard Dawkins (1998) has a nine and a half page 'selected bibliography'. It is Dawkins' style not to cite others' work a great deal in this book but on a couple of occasions I found in my brief survey I found him not to cite page references either. His reference to Lewis Wolpert's (1992) book (Dawkins 1998:p178), quotation of Thomas Huxley (p179) and reference to Pinker's 'How the Mind Works' (1998) could all be criticised for this.

Elaine's first book, 'Descent of Woman' (1972) has a two page bibliography but, in my brief review, appeared to be poorly referenced. Morgan (1972:p135) cited Weinstein (1966) as establishing that pig epidermis and human skin 'contains similar proteins.' This is hardly a ground-breaking point but there is no reference to this citation at all. This appears to be quite typical in the first book.

Her second 'The Aquatic Ape' (1982) has two and a half pages of bibliography. Although it appears to be better referenced than 'Descent' I quickly found examples of citations (to C. R. Taylor 1970 - Morgan 1981:p55 and Donskoi 1961, Slijper 1962, Scott 1963 and Cooper 1968 on page 59) which were not referenced at at all,

'Scars of Evolution' (1990) has seven and a half pages of references and appears to be better referenced than the preceding books. Page numbers are still not used for the citations I found, however.

'The Descent of the Child' 1994 has four pages of references and, it has to be said, appears to be less well referenced than 'Scars'.

Morgan's latest book 'The Aquatic Ape Hypothesis' (1997) has eighteen and a half pages of references and is much more scholarly in it's standard of referencing. Using the same 'quick scan' method I was not able to find a single citation that was not fully referenced with page numbers included.

So, what conclusions can be made? Well, it has to be said that Morgan's earlier books (all except the last) can be criticised for their quality in referencing if one is comparing them with most other popular science books. To be fair, however, it should be noted that this is not a fault unique to Elaine Morgan books. Morris' 'Naked Ape', for example, appears to be at least as bad and, as this was one of the key books on which inspired Morgan to write about this subject, perhaps it is not surprising that she based her standards on his.

About her latest book Moore writes "Morgan has written another book on this subject (The Aquatic Ape Hypothesis, 1997); as a refreshing change this time, she has included references for some, but by no means all of her statements (this is perhaps to be expected since many if those statements are false)." This claim is, yet again, not backed up by any citations however and, at best, could be characterised as rather ungenerous.

Moore admits that he hadn't yet "had the chance to check the references for her quotes to see if this book is a change to her well-established pattern of using misquotation" - again, so far, not one example of this has been cited - but claims that it "does still use most of the AAT's established 'false facts' to support her theory, including the thoroughly discredited material on fat, tears, the larnyx, hymens, direction of the nostrils, etc., which this site covers." We will see if these "established 'false facts'" are as established as he claims later. But it is interesting that not one single allegation of his has yet been backed up by anything at all even though he promised us that his web site would set far higher standards than those adopted in Morgan's work.

Moore then goes on to mention other AAH advocates - well one other. He would deserve some credit for this if he hadn't done it in such a childish way. He writes "There have been a few other people who've done articles on the AAT, and they belie Morgan's claim that you can't publish academic articles on the subject." Again, no citation of that claim is given. Once more, it seems we just have to take his word for it. It does seem rather a remarkable claim to make and, having spoken to Elaine about this personally several times, she certainly would not hold any such view. This is very close to what one might call a misquotation, except of course Moore offers no citation for it.

About that other proponent, Moore writes "Although Verhaegen's articles do have references, they also contain statements such as claiming that rhinoceros are "predominately aquatic", and several other howlers. So, in one sentence the whole or Marc Verhaegen's work is dismissed. I do not think that this sets a very high scholarly standard from which to throw stones at the AAT greenhouse.

Moore even mentions the Roede et al (1991) summary of the symposium and recommends it for further reading, which deserves credit but feels obliged to qualify this with "the pro-AAT articles in that book are distinctly amateurish compared to the ones which don't support the AAT." This is purely his subjective opinion and, even if true, should not reflect on the arguments being promoted in those papers, for or against.

He concludes this section by writing: "P.S. One thing I found from posting on this subject in sci.anthropology.paleo is that Elaine Morgan
A) doesn't like it when you imply she is the primary proponent of this theory (she is certainly the best known and widest read); and
B) doesn't like it when you mention any claims made by AAT proponents other than her." No reference is given for this statement either, but we're kind of getting used to that by now. It's difficult to know why Jim felt the need to put this in, other than some kind of childish put down to leave the reader in no doubt, not that what he's written already gibes anything but that picture, that he doesn't really like her very much.

The method of the aquatic ape theory (AAT)
The next section sets out to critique the method of the AAT. It begins with Moore's definition of the AAT, for the third time, with the same two errors.

Moore states that the method behind the AAT "consists of an extremely heavy reliance on a flawed understanding of the evolutionary concept of convergent evolution as a mechanism and an equally extreme adaptionist view." He does not attempt to substantiate his claim that the AAT understanding is "flawed" however. He is correct, however, in suggesting that it is based on convergent evolution and a rather neo-Darwinist adaptationist viewpoint that most extant traits should be explicable as some kind of adaptation to past or current habitats. The AAH is based on questions like this. Humans are naked and fat, apes aren't. Why should that be the case? Where else do you find such examples in zoology? To argue against the adaptationist program, as did Gould and Lewontin (1979) is to argue that such traits are merely spandrels (or chance side products of construction). Such traits may well be explicable in those terms but only after all other plausible mechanisms have been eliminated.

Moore argues that "AATers also make the mistake of supposing that even very distantly-related animals in a common environment should evolve the same mechanisms for dealing with any given problem." At least, for the first time, Moore does attempt to back this claim up with something although the citation he gives is of doubtful benefit. He adds... "for instance, believing that if hominids had a land-based transition they would've have used the same form of thermoregulation as "the wild ass and the camel" (Elaine Morgan, in her 1990 book, The Scars of Evolution: "On the supposition that man's ancestor's moved out from the trees to open ground and needed sweat-cooling, they might be expected to have followed the example of the wild ass and the camel in adapting their apocrine glands for that purpose."). Notice there is no page reference for this quote.

Even this is an argument of convenience, however Often on the s.a.p. newsgroup 'aquasceptics' have argued against the AAH on precisely the opposite grounds: That if, humans had been semi-aquatic we'd have have webbed digits like all other semi-aquatic animals. (e.g. Keeter  2002).

Moore given another example of exactly the reverse argument himself that "while the observation that non-human savannah mammals don't predominately walk bipedally and predominately cool by sweating via eccrine glands is considered devastating evidence against a terrestrial divergence for our ancestors, but the fact that no non-human aquatic mammals do so is simply ignored." He claims that this is an example of the AAH adopting double standards but, actually, he is merely demonstrating that both sides are capable of using arguments of convenience when it suits them.

Moore suggests that "asking why humans are so incredibly different from aquatic mammals in the actual traits which are ubiquitous in such mammals is also apparently a no-no" but this actually merely demonstrates his misunderstanding of the hypothesis. The AAH does not suggest that humans were ever as aquatic as such aquatic mammals so, it is exactly as predicted that we should be very different from them.

What are some of the other problems with AATers' methods?
In another section Moore characterises the AAH argument thus: "1. Feature A cannot have evolved on land. 2. Feature A is found only in humans and aquatic animals. Therefore Feature A is evidence of an aquatic transition from LCA to hominid" although nowhere does he cite any proponent of the AAH who has ever argued that. He is overstating the case somewhat. It is not so much that feature A cannot have evolved on the land but that there are fewer analogues in purely terrestrial mammals than in ones with more of a water-side life. Moore does not, it should be noted, cite a single reference to any AAH proponent that states anything like 'this feature is only found in humans and aquatics.' It would make his case much stronger if he had done so.

He then claims that the research for such traits has been poor. As few professional scientists have taken any interest in the AAH, it is not surprising that even more than forty years after Hardy first published the idea, very little research has been done.

Moore further argues, without giving any examples, that "many of these features are not unique to humans amongst terrestrial animals" and that "many of them are shared by only a few aquatic mammals." If he is referring to hairlessness, for example, that is undoubtedly true. But no-one has ever argued that nakedness is unique to humans and aquatics, just that nakedness in mammalia is disproportionately better represented in aquatic genera than in terrestrial ones.

This is stretching the AAH argument enough, but Moore has not finished. He goes on to make this astonishing claim: "And those features which actually are ubiquitous amongst aquatic mammals -- and which therefore would be expected to be found in a mammal which evolved in an aquatic environment -- are (just by coincidence?) features which AAT proponents have consistently ignored, because none of them are seen in humans or our hominid ancestors. So one essential technique of the AAT is, ironically, to ignore all actual aquatic features."

As no AAH proponent has ever argued that humans were as aquatic as the truly aquatic mammals, it is not surprising that the traits Moore is presumably thinking of here (traits like fins and a seal-like body shape with greatly reduced limbs) are absent in humans. The AAH does ignore actual aquatic traits like fins and gills simply because it never postulated that humans were ever more aquatic than otters are. If Moore didn't even understand this, no wonder he was so confused and irritated by it.

Straw Men or Straw Mermen?
Moore has just shown a typical aquasceptic argument - to push the assumed degree of aquaticism being proposed to such an extreme that it becomes easy to refute. If the AAH can be seen to be arguing that humans descended from dolphins even a child would declare that it was nonsense. Unfortunately even the adult aquasceptics' counter arguments are not much more sophisticated than this. What Moore and others are doing is this: "Stating a misrepresented version of an opponent's argument for the purpose of having an easier target to knock down." Moore offers this himself as a definition for the term 'straw man' but, ironically, is claiming that it is the proponent of the AAH that typically uses this technique.

Moore trots out the usual counter arguments about the savannah not being a "waterless, treeless plain". Others (e.g. Langdon 1997 ) have implied that the 'savannah hypothesis' was actually an invention of Elaine Morgan but workers like Tobias are under no such illusions. He wrote "until recently, the evolution of early hominids in the savanna has been a strongly held, prevailing hypothesis. Yet some of these human characteristics would have made us hopeless savanna-dwellers." Tobias (2002: p15). The point Tobias makes is that it was a prevailing view that East African aridity resulting in the opening up of closed forest habitat which drove the process of hominidisation. (see, for example, Coppens 1992; Vrba 1985). It amounts to special pleading that this was not the general understanding. As Richard Potts put it "Over much of the twentieth century, scientists thought that human evolution entailed a simple trajectory from apelike to humanlike and that this process was promoted by the challenges of an open savanna." Potts (1998:106)
Practically every documentary ever made about human evolution and every artists impression ever drawn of early hominids depict a cave man stepping out onto open grasslands with a spear in hand. And yet, not only does Moore have the nerve to claim the AAH argument relies on this as a kind of straw man when it is clearly not a straw man argument at all, but he simultaneously uses a real straw man (or in this case a straw merman) argument himself. The double standards are there for all to see.

Shifting Targets
Another claim made by Moore is that "AAT theorists have also gone for that classic technique among marginal theories, the shifting target. Specifically, the "aquatic apes" have become less and less aquatic over the years, from being fully acclimated to sea life, diving, etc., to seashore-dwelling waders, to denizens of the shores of streams and inland lakes." Moore could substantially increase the persuasiveness of this argument if he had a few quotes to back it up from Morgan's work, which spans twenty-five years, but instead, all we get is a couple quotes from scraping the sci.paleo.anthropology newsgroup barrel.

As means of another 'example' Moore offers this: "As one example, with the change in the AAT mentioned above (i.e., a less aquatic wading ape), the AAT claim that these hominids would not and could not evolve bipedal posture and locomotion without being in neck-deep water falls by the wayside... and yet they still use that claim." Again, no citation is within sight. (How is a reviewer meant to check this, Jim? - I mean, even Elaine's earliest books gave more of a clue than this!) If we spend even a second to re-read that, we can see that it is just absolute nonsense. The idea that a hominid would only evolve bipedalism in neck deep water is absurd, it clearly would swim at such depths, as do humans. This is crazier than anything any AAH proponent has ever written.

Moore writes "AATers simply say their theory is adjusting to new evidence, as any scientific theory should" and that is exactly right and about all that has to be said on the matter.

Comically, Jim Moore then gives us "several" (three actually) reasons, if some of the AAH arguments have been dropped, why he still went to all this trouble to document them. It turns out that reason 1 (ideas are dropped by one AATer are continued to be used by other AATers), reason 2 (One AATer drops the idea but then carries on using it) and reason 3 ('false facts' that have been dropped 'continue to pop up again and again') Excuse me, but aren't those all the same reason?

At the end of the day arguments come and go, pieces of evidence emerge which cause existing theories to look less likely and others to be rekindled. What's Moore's point? That only the AAH is prone to this and no other theory?

What about credentials -- do they matter?
His final section on this page asks that question and Moore offers an immediate answer: "Not to me". To his credit, Moore states that to him it "matters not one whit" about the paleoanthropological credentials of the three chief proponents Hardy, Morgan and Verhaegen as long as they "do the research that's needed to build a new theory". Unfortunately, he claims, they have not.

He gives an example of such a scientist without credentials who has credibility - Alan Mootnick, apparently a gibbon specialist. He argues that Mootnick has gained this credibility by doing the work but ends by suggesting that "unfortunately, this process of digging out actual facts and reporting them accurately, and of making logical conclusions, does not describe the AAT research to date."

Well, unfortunately for Jim, I think he's been guilty of far worse himself in the two pages so far. He accuses Morgan of not giving full references and yet hardly gives a single one himself. He accuses her of straw men argument when she isn't and then uses the same tactic himself. We shall see if there is any substance to such claims but, so far, it does not look good.


Keeter, Bob (2002)
Cited arguing about webbing as a missing aquatic adaptation on the s.a.p. newsgroup. (Go to Google Groups and search for "Keeter Webbing")

Crawford, Michael A; Marsh, David (1989). The Driving Force. Harper & Row (New York)

Dawkins, Richard (1998). Unweaving the Rainbow. Penguin (London)

Ellis, Derek V (1993). Wetlands or Aquatic Ape? Availability of food resources. Nutrition and Health Vol:9 Pages:205-217

Gould, Steven J; Lewontin, R C (1979). The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme. Proceedings of the National Academy of Sciences of London Series B Vol:B 205 Pages:581-598

Hardy, Alister (1960). Was Man More Aquatic in the Past?. New Scientist Vol:7 Pages:642-645.

Jay Gould, Stephen (1977). Ever Since Darwin. Penguin (London)

Leakey, Richard E F (1994). The Origin of Humankind. Weidenfeld and Nicolson (London)

Morris, Desmond (1967). The Naked Ape. Vintage

Morgan, Elaine (1972). The Descent of Woman. Souvenir Press (London)

Morgan, Elaine (1982). The Aquatic Ape Theory. Souvenir Press (London)

Morgan, Elaine (1990). The Scars of Evolution. Oxford University Press (Oxford)

Morgan, Elaine (1994). The Descent of the Child. Penguin Books (London)

Morgan, Elaine (1997). The Aquatic Ape Hypothesis. Souvenir Press (London)

Pinker, Steven (1994). The Language Instinct. Penguin (London)

Potts, Richard (1998). Environmental Hypotheses of Hominin Evolution. Yearbook of Physical Anthropology Vol:41 Pages:93-136

Sera, G L (1938) Achivo Zoologico Italiano Vol 25.

Tobias, Phillip V (2002). Some aspects of the multifaceted dependence of early humanity on water. Nutrition and Health Vol:16 Pages:13-17

Verhaegen, Marc; Puech, Pierre-Francoise; Munro, Stephen (2002). Aquarboreal Ancestors?. Trends in Ecology and Evolution Vol:17 Pages:212-217

Vrba, Elizabeth (1985). Ecological and Adaptive Changes Associated with Early Hominid Evolution. In: Delson, Eric (eds.), (1985). Ancestors: The Hard Evidence. Alan Liss Inc (New Yotrk)

Westenhöfer, Max (1942). Der Eigenweg des Menschen. Mannstaedt & Co (Berlin)