Re: AAH Evidence?

Phillip Bigelow (
Thu, 22 Dec 1994 05:28:17 GMT (Bryce Harrington) writes:

>In _The Journal of Laryngtology and Otology_, March 1992 Peter Rhys
>Evans wrote that auditory canal exostoses, a bony swelling of the
>external ear canal, might prove the theory. These exostoses have been
>demonstrated to occur in humans and guina pigs that are repeatedly
>exposed to cold water. "The relationship between swimming and
>exostoses is a phenomenon well known to otolaryngologists, but the
>relevance of their pathogenesis has been largely overlooked by
>physical anthropologists and archeologists..."

>The presence of exostoses in fossil remains would be unquestionable
>evidence for the aquatic theory, but I hesitate to say that they
>*must* be found in the remains for the theory to be true for several
>reasons. First, as Evans points out, the eroded state of remains of
>typical fossils might make identification of such abnormalities
>difficult. Second, this effect is not genetic but something which
>occurs to an individual during its lifetime, so a creature lacking
>exostoses may have come from a post-aquatic stage. Third, and most
>importantly, it has been observed that, "In warmer climates they are
>found less frequently." Since the postulated ape lived in a tropical
>condition the presence of such abnormalities should not be expected to
>be too high.


An interesting bit of information. I see one major problem with this
evidence: It is pathologic, rather than phylogenetic. To show evidence
that a _species_ (in other words, the _entire_ population) is aquatic, you
must show that the structural changes in the ear canal is an _adaptation_ to
an aquatic existence. The structural changes you are refering to are
changes that occur as a consequence of living. If you found 10 or so skulls
that showed this condition, you _still_ wouln't know if it was due to an ear
infection, or to exposure to water, or to exposure to cold wind. It has to
be a phylogenetic character trait to be evidence for a habitat preference of
_all_ individuals in the species. Otherwise, it would be anecdotal
evidence. The character trait must be an _inherited_ trait.
(Did you happen to note that both species that were studied happened to be
_TERRESTRIAL_ animals?) :)