Re: Dinos-Darwin-Gould

[Rosser Jr, John Barkley]

Ricardo,
     Thank you for admitting you don't have a source.  Your 
speculation that the dinos were in decline before the 
asteroid hit is just that, speculation.
     It is possible to accept punctuated equilibrium that 
is not exogenously driven, although it may be in major 
cases (like asteroid hits).  Also, it does not imply that 
any particular change is "progressive."
Barkley Rosser
On Thu, 30 Apr 1998 11:07:53 -0400 Ricardo Duchesne 
<[EMAIL PROTECTED]> wrote:

> > Date sent:      Tue, 28 Apr 1998 17:10:28 -0400 (Eastern Daylight Time)
> > Send reply to:  [EMAIL PROTECTED]
> > From:           "Rosser Jr, John Barkley" <[EMAIL PROTECTED]>
> > To:             [EMAIL PROTECTED]
> > Copies to:      [EMAIL PROTECTED]
> > Subject:        Re: Liebig's Law and the limits to growth
> 
> >      I apologize to the list for getting into this again, 
> > but I must say that I have never seen anywhere any claim 
> > that the dinosaurs had been declining for two million years 
> > prior to the asteroid hit, much less any credible data on 
> > why such a decline was occurring.   Could you provide the 
> > source where you read this, please, Ricardo?
> > Barkley Rosser
> 
> 
> The way I worded that last missive was misleading. I meant to say 
> that once the asteroid hit it took over two million years for the 
> dinos to become extinct. On the other hand, the dust that rose up as 
> a result of the asteroid must have come down to the earth in less 
> than a year. So, it is better to think of the asteroid as 
> accelarating a process that was already in place, namely, the normal 
> process of decline that species experience. That's why I also said 
> that the dinos were already in decline prior to the asteroid; the 
> asteroid then hit but did not wipe then out, as they continued to 
> roam around for two more million years.   
> 
> Source? I just recall reading the two million thing and the 
> dust falling in less time than that. I don't have available right now 
> a full paper or argument. What's wrong with catastrophe theories is 
> that it sees evolution as the plaything of external environmental 
> forces. Gould's theory of "puntuated equilibria" says that "stasis" 
> is the normal feature of evolution . Change - leading to new species -
> results when some external episode disturbs this equilibrium. So, 
> only because an asteroid hit did dinos disappear and mammals 
> became the dominant species. 
> 
> He does not reject Darwin's theory of natural selection, that 
> evolution is a result of organisms struggling for survival. But he 
> does reduce selection to "a principle of local adaptation, not of 
> general advance or progress" (See his excellent article in 
> Scientific American, "The Evolution of Life on the Earth, October, 
> 1994). Rather, "General advance" is seen as a result of external 
> forces, which led to the mass extinctions of previous creatures, "for 
> reasons unrelated to adaptive struggles", allowing new species to 
> come onto the scene.   
> 
> Gould is highly uncomfortable with any notion of evolutionary 
> progress, "that evolution means progress defined to render the 
> appearance of something like human consciousness either virtually 
> inevitable or at least predictable. The pedestal is not smashed until 
> we abandon progress or complexification as a central principle and 
> come to entertain the strong possibility that H. sapiens is but a 
> tiny, late-arising twig on life's enormously arborescent bush..."
> 
> I think we can reject any notion of inevitability without denying 
> the principle of "complexification". These are two very different 
> things. Without Gould's complex mind none of the above would be known.
> 
> ricardo
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> > On Tue, 28 Apr 1998 16:01:21 -0400 Ricardo Duchesne 
> > <[EMAIL PROTECTED]> wrote:
> > 
> > > > Date sent:      Tue, 28 Apr 1998 09:59:59 -0700
> > > > Send reply to:  [EMAIL PROTECTED]
> > > > From:           James Devine <[EMAIL PROTECTED]>
> > > > To:             [EMAIL PROTECTED]
> > > > Subject:        Re: Liebig's Law and the limits to growth
> > > 
> > > > The more I think about question of the causes of the mass extinction of the
> > > > dinosaurs, the more I think that it may be like that of the fall of the
> > > > Roman Empire. There are lots of good reasons why the Empire fell -- but
> > > > there's no reason to presume that (absent these causes) it would have
> > > > lasted forever. So maybe the question should be "why did the Roman Empire
> > > > last so long?" Similarly, I think Barkley is right that the scientific
> > > > community may be reaching a consensus that the "comet done them in." But
> > > > that may be only what Aristotle called the "efficient cause," the trigger
> > > > that caused a slide that was already ready to happen. It's possible that
> > > > dinosaurs had become over-specialized in a way that made them especially
> > > > vulnerable to shocks of the sort that comets cause. (Think of T. Rex, the
> > > > over-specialized eating machine.) The normal predator-prey cycle may have
> > > > become unstable, ready to be pushed off the region of regular fluctuation
> > > > into the region where the predators eat all the prey, killing off their
> > > > food supply and thus their own futures. If this is so, enquiring minds want
> > > > to know. 
> > > 
> > > 
> > > Yes, I think this is a much better way of stating this issue than the 
> > > catastrophe theory would have it. One problem with this 
> > > theory, so I read, is that the end of the dinosaurs, once the 
> > > decline started,  occurred over a period of two million years. 
> > > Afterall, that they were already in decline when the 
> > > asteroid hit (due to their overspecialization, as Jim suggests) is 
> > > simply part of the normal rise and fall of species.   
> > > 
> > > A more fundamental theoretical problem with this theory is that it 
> > > ignores the *internal* dynamics of evolution. Gould puts too much 
> > > emphasis on the external environment (and accidental changes 
> > > thereof). He is so against any notion of evolutionary "progress" that 
> > > he can make no distinction between humans and bacteria!
> > > 
> > > ricardo
> > >  
> > > > I think that the dinosaurs' fate is quite relevant to pen-l. After all, our
> > > > non-socialist friends and colleagues think of us as dinosaurs! We should
> > > > show some inter-species solidarity. More seriously, past mass extinctions
> > > > are quite relevant to understanding the current on-going mass extinction.
> > > > 
> > > > I think biology and evolutionary theory are quite relevant to understanding
> > > > economics and political economy (though I'm no Herb Gintis, who currently
> > > > seems to want to reduce it all to evolution). The "dialectics of nature"
> > > > (the regularities of evolution, etc.) can help us understand the dialectics
> > > > of human society (class conflict, crisis, change, etc.) -- as long as we
> > > > don't pretend that the dialectics of human society are the _same_ as those
> > > > of non-human nature. We have consciousness and language, while we "evolve"
> > > > mostly by developing culture, technology, and institutions, which follow
> > > > more of a Lamarkian process in which "aquired traits are inherited" than a
> > > > Darwinian one. 
> > > > 
> > > > in antediluvian solidarity,
> > > > 
> > > > Jim Devine [EMAIL PROTECTED] &
> > > > http://clawww.lmu.edu/Departments/ECON/jdevine.html
> > > > "The only trouble with capitalism is capitalists. They're too damned
> > > > greedy." -- Herbert Hoover
> > > > 
> > 
> > -- 
> > Rosser Jr, John Barkley
> > [EMAIL PROTECTED]
> > 
> > 
> > 

-- 
Rosser Jr, John Barkley
[EMAIL PROTECTED]