D'Abrera on Science and Philosophy

John Grehan jrg13 at psu.edu
Fri Jul 31 23:14:23 EDT 1998

I have some comments on comments by Foley. I realize this topic is more
about evolution than Lepidoptera per se so I am willing to discontinue
further responses if subscribers object. Sincerely, John Grehan

>The role of natural selection is well documented in Lepidopteran mimicry, 
>crypsis and other wing pattternings. If you doubt this examine the work 
>of E. B. Ford, H. Kettlewell, J. Turner and many others. This is not just 
>a matter of casual observation. Lots of careful data collection and 
>hypothesis testing has been done on the subject.

Selective interactions as ecological process are well documented I would

 Although the ultimate source of variability 
>is random mutation

I question the "random" aspect

, the mutations express themselves through 
>developmental channels that have been themselves selected.

I question whether these "developmental" channels have been "selected" in
the sense of natural selection through fitness.

>variants show many constraints, as may be seen by an examination of F. 
>Nijhout's 1991, book The Development and Evolution of Butterfly Wing 
>It is no rejection of Darwin to argue that the course of evolution is 
>guided by not only selection but also the patterns of genetic 
>variability. In fact that is exactly what Darwin believed.

Darwin believed in "laws of growth". As far as I am able to interpret his
writings on this subject, he believed that variation can and did evolve
without the action of natural selection, and expressed the view that he may
have overstated the role of natural selection in the origin of adaptation.

 To imagine 
>that the genetic variability is guided by supernatural forces 

Where did I mention supernatural forces? 

is to reject 
>the consensus of scientists

Many current consensus views have arisen from rejection of earlier
consensus, so such rejection of itself hardly seems basis for criticism.
However, I am not rejecting the consensus that "natural" forces shape
events (but I have to be agnostic about the ultimate nature of reality as
this is beyond my resources of knowledge).

 (reflected most notably in the work of Darwin, 
>Lyell and Newton) that natural phenomena depend on natural laws.

What natural laws are being rejected? (by me at least)

>patrick foley
>patfoley at csus.edu

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