From newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!psych.toronto.edu!christo Tue Jun  9 10:06:54 EDT 1992
Article 6078 of comp.ai.philosophy:
Newsgroups: comp.ai.philosophy
Path: newshub.ccs.yorku.ca!ists!helios.physics.utoronto.ca!news-server.csri.toronto.edu!psych.toronto.edu!christo
>From: christo@psych.toronto.edu (Christopher Green)
Subject: Re: Grounding: Real vs. Virtual (formerly "on meaning")
Organization: Department of Psychology, University of Toronto
References: <21813@castle.ed.ac.uk> <1992May25.202001.7388@psych.toronto.edu> <21988@castle.ed.ac.uk>
Message-ID: <BpBs89.72D@psych.toronto.edu>
Keywords: symbol, analog, Turing Test, robotics
Date: Thu, 4 Jun 1992 14:28:56 GMT

In article <21988@castle.ed.ac.uk> cam@castle.ed.ac.uk (Chris Malcolm) writes:
>In article <1992May25.202001.7388@psych.toronto.edu> christo@psych.toronto.edu (Christopher Green) writes:
>>In article <21813@castle.ed.ac.uk> cam@castle.ed.ac.uk (Chris Malcolm) writes:
>
>>>When proto-humans were subject to fierce evolutionary pressure to become
>>>smarter -- and the speed with which our large brain evolved suggests
>>>that this pressure was fierce [...]
>
>>This is a very poor evolutionary inference. These sorts of just-so stories
>>just aren't borne out by much of the paleontological data. 
>
>Very few palaeontologists now doubt that a) one of the last major
>evolutionary change suffered by humans was the enlargement of the
>brain, and b) that this developement took place unusually rapidly.
>Your mention of "palaeontology" does make me wonder, however, whether
>you have noticed that palaeontology is no longer the pace-maker in the
>chronology of human evolution.

Pace-making is of little interest to me. The Paelontologists have made
more than adequate responses to most of the geneticists more outlandish
claims. For those who haven't been keeping up (and I'm not intending to
include you in this group Chris -- insult always seems to be assumed on the
net) take a look at the two articles on "Eve" in _Scientific American_ last
month.
>
>>Evidence is that
>>when "evolutionary pressure" is put on creatures, they almost always die off,
>>and their niche is filled by another species better suited to the new 
>>environment.
>
>Quite so, they usually do, but not always. The exceptions happen in
>circumstances where other candidates are not available. 
>
Whether other candidates are available has little -- actually nothing -- 
to do with whether speies that have been subjected to evolutionary change
die off or "evolve".
>
>It seems that it is you who are in need of a more sophisticated
>description. From the premise that evolutionary pressure _usually_
>leads to extinction and replacement you deduce that it cannot fail to
>do so; 

Not at all, I'm just playing the odds. Nevertheless, evolution can
take place for all kinds of reasons having little to do with specific
environmental pressures. Some changes follow along with funtionally 
unrelated changes  that are being subjected to einvronmental pressure
which happen to be mediated on the same chromosomal loci. To merely
speculated for a moment, an attribute as generally useful as high intelligence
doesn't seem to be the obvious result of a specific environmental change
(compare with, e.g., longer necks).  It would be advatageous for any
species anywhere. 

>I have rarely been subjected to such a half-baked and irrelevant
>attack! Care to try again?

Keep it clean. "Just-so-story" is a phrase commonly used in the evolutionary
literature to described "How-the-human-got-his-big-brain" accounts. Yours
seemed to fit this category. I apologize if insult was taken. It seems to
me that "half-baked" is a phrase more applicable to the accounts of your 
"pace-makers", the geneticists, than almost anyone else in science. The
parallels to early forays of Computer Scientists into psychology are almost
unmistakeable.

Regards,

-- 
Christopher D. Green                christo@psych.toronto.edu
Psychology Department               cgreen@lake.scar.utoronto.ca
University of Toronto
---------------------


