Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!umich!sharkey!tygra!dave
From: dave@tygra.ddmi.com (David Conrad)
Newsgroups: comp.ai
Subject: Re: evolution is not a scale
Summary: and environment is not a constant
Keywords: Primordial Soup, changing environment
Message-ID: <1990Dec22.084106.26089@tygra.ddmi.com>
Date: 22 Dec 90 08:41:06 GMT
References: <70996@bu.edu.bu.edu> <1870014@hpwrce.HP.COM>
Organization: Society for the Improvment of Society
Lines: 38

In article <1870014@hpwrce.HP.COM> kingsley@hpwrce.HP.COM (Kingsley Morse) writes:
>
>Do you think it's possible that Darwin's theory of natural selection uses
>"fitness" as a goal? In other words, Darwin proposed that "survival of the
>fittest" causes succeeding generations to be ever better adapted to
>the environment. Could successively fitter generations be considered a "scale",
>in that any given branch of evolution has "fitter" genes at it's leaves than
>at the root?

Certainly the process of natural selection tends to produce creatures
which are better adapted to their environment, but it must be remembered
that the environment is not a constant.
 
There is a theory which postulates that the Earth had, at the time life
emerged, an atmosphere consisting of perhaps methane, who knows what
else, and little oxygen. (Obviously I am not an expert in these matters,
and I don't know the current status of this theory.)
 
Assuming that the environment of the Earth at that time consisted of
this so-called Primordial Soup, it would be naive to suggest that we
humans are "fitter" (read: better adapted) for that environment than
the creatures alive at the time were. Indeed, were you or I to time
travel to that period we would asphyxiate and expire in short order.
 
My point, essentially, is that a creatures "fitness" can only be judged
w.r.t. its environment, which is variable (albeit over large time frames,
unless global warming is correct, in which case we find out just how
quickly we can adapt).
 
Regards,
David R. Conrad      | "Playing at the hard-case, you follow the example of
dave@tygra.ddmi.com  | the comic-paper writer, who lets you bend the rules."
...!uunet!tygra!dave |		-- Jethro Tull, _Thick as a Brick_
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