Re: The straw man.

Alex Duncan (
8 Nov 1995 15:15:50 GMT

In article <47qcd3$> Thomas Clarke, writes:

>You have an interesting view on falsificiation, it is relative, time
>My first reaction is that this is wrong. In physics there is the
>idea of a critical experiment, like the Michaelson-Morely experiment
>with regard to the existence of the ether. The ether is dead,
>it will stay dead. If a later theory introduces something that looks
>like an ether, then it will be the case that to a good approximation
>the new ether-stuff doesn't exist in the regime that M-M tested, that
>is the classical idea of ether will stay disproven.

Unfortunately, falsification is not so powerful a term in the historical
sciences. For example, as far as some people are concerned, the idea
that A. afarensis spent any time in the trees has been falsified. For
others, the idea that A. afarensis was restricted to terrestrial
locomotion has been falsified. There is a basic disagreement about the
significance of the evidence at hand.

>Why am I carrying on so? I am just bemused by your absolute opposition
>to the AAT. I would think that the proper attitude would be
>something like "The AAT is a hypothesis with little chance of being
>correct." If I were a budding PAist I would tuck the AAT into the
>back of my mind. Then if some strange fossil were to come your way that
>demanded an aquatic explanation, you would be prepared and could scoop
>the other PAists. Keep an open mind.

I am not absolutely opposed to the AAH. I have put some serious thought
into the arguments for the AAH, and have decided that they are not
supportable, largely for two reasons. Supposedly unique human features
that have been used to support AAH either 1) are found in a variety of
other strictly terrestrial animals, or 2) have been more than adequately
explained in the context of the unique human adaptation to a diurnal,
tropical, terrestrial, omnivorous niche.

>By the way, what's the official PA line on the so-called
>"West Side Story" - hominid, pongid speciation caused by geographic
>isolation of the African Rift?

It's been a long time since I read the article you mention. However,
geographic isolation of protohominids from proto-African apes has long
been a part of most models that attempt to account for the initial
speciation event. If African rifting can supply an isolating mechanism,
then I suppose it's plausible. My one concern with the idea is that our
picture of early hominid geographic range is severely biased by the fact
that most early hominid fossils are associated with the rift, which
provided both a good depositional environment for the preservation of
fossils, and a nice landscape for their eventual discovery. I suspect
that the true ranges of the earliest hominids were much broader
geographically. The rift valley provides us with a very small window on
what was really going on.

Alex Duncan
Dept. of Anthropology
University of Texas at Austin
Austin, TX 78712-1086