Jim Moore's "AAT Sink or Swim?" Web Site
AAT Claims and Facts: The "Swimming Babies" Reference
No other pieces of evidence are cited for or against the claim which on the face of it seems quite compelling: that human infants are more buoyant and adept in water than our chimp cousin's are.
On this page Moore makes one (again unattributed and this time rather mysterious) claim about the AAH on the subject of infant swimming ability. It alleges a misrepresentation but does not offer any more discussion on the matter than that.
The "Swimming Babies" reference
And then we have the usual Moore technique: Quote one, selected argument that he claims has been used in favour of this idea and debunk it.
Moore claims that "they usually actually give the reference: "M. McGraw, Journal of Pediatrics, 1939:485-490" but that his evidence is misrepresented because "they" (whoever they are) fail to mention that the same paper also looked at other mammals too: opossum, rat, kitten, rabbit, guinea pig, and rhesus monkey, and he found no difference between them and the humans.
Moore ends with this: "Note that an older chimpanzee was also tested and, just like older human infants, was inactive when placed in the water. Note too that this study found that "at no time did any baby show himself capable of raising his head above the water level for the purpose of breathing". So that's the sad secret of the drowning infants; what we actually find here is not so much "swimming babies" as infant mammals slowly drowning without a struggle."
Two questions arise from this:
1) Do AAH proponents quote or misquote the McGraw paper in the way Moore suggests? and
2) Is this the only evidence in the literature pertaining to the ability or lack thereof of human infants to swim compared to their nearest relatives?
the McGraw paper?
Once again, I went through all of the literature I have on the AAH and I couldn't find a single reference to it, not even in 'Descent of the Child' Morgan (1994), the one book you'd expect to find something like this.
Her latest book does allude to the subject, however. She writes: "I have not seen this [the idea that a human infant can float on the surface of the water unsupported] recorded in the scientific literature, but I have seen vivide sequences in an Australian film of a baby floating unsupported, resting comfortably on the surface of the water, accompanies by a commentary stating: 'This baby floats happily in water and has done so since birth.'" (The film she watched was referenced in the bibliography as: 'Water Babies' (1985) Golden Dolphin Productions, Ltd, Producer Robert Loader, director Tristram Miall.)
So, what are
we to conclude? Did Moore just make it up? I doubt he would stoop so low as
that, but I suspect what he is doing is reporting a citation used on a
internet forum and portraying it as 'the official AAH view'.
any other evidence on this?
Just search Google on the web and you'll se what I mean. I did a search on 27th March for "infant swimming classes baby" and it returned 49,000 pages!
Of course just because there are absolutely zero cases of anything remotely similar with chimpanzees does not mean anything. But when one considers the relatively high subcutaneous fat content of a human infant compared to that of other terrestrial mammals, including, in all likelihood, chimpanzees, (Kuzawa 1998:181) it seems to be entirely plausible that human infants are much more buoyant and therefore relatively comfortable in water.
Finally an answer should be offered to answer the original question Moore posed: If humans had a more aquatic past, how come so many infants drown?
The simple answer is: Because many infants die, many are likely to drown in water simply because humans tend to live close to water sources.
One might pose a similar question: If chimpanzees were arboreal, how come so many infants die falling from trees? Of course they are, at least partly arboreal. It is the fact that they spend so much time in trees with their infants that makes it a significant cause of death.
Just because an animal is adapted to a certain environment (and, remember, in the case of the AAH the argument is merely that our ancestors were more adapted than we are today and than our great ape cousins ancestors were) it does not mean that the level of adaptation will be perfect. Environments can change, and so adaptations are often mapping onto a moving target at the best of times. In the case of human evolution, this was almost certainly the case as habitats seem to have fluctuated widely over the past 3-5 my.
Kuzawa, Christopher W (1998). Adipose Tissue in Human Infancy and Childhood: An Evolutionary Perspective. Yearkbook of Physical Anthropolgy Vol:41 Pages:177-209
McGraw, M (1939) Journal of Pediatrics,
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)
Smith, Anthony (1985) The Body, Routledge
Verhaegen, Marc (1991). Human Regulation of Body Temperature and Water Balance. In: Roede, Machteld; Wind, Jan; Patrick, John; Reynolds, Vernon (eds.), (1991). Aquatic Ape: Fact of Fiction: Proceedings from the Valkenburg Conference. Souvenir Press (London)