Mutations ? (Re: D'Abrera on Science and Philosophy)

Doug Yanega dyanega at
Tue Aug 4 11:35:36 EDT 1998

To prolong things, I have two comments in regards to points in John
Grehan's latest:

>>If we look at a classical mullerian mimicry system, like the
>>burnet moths (Zygaena) or the genus Heliconius, the whole system
>>is convincing. As a monophyletic group, the ancestors of all
>>species share the same potential of variability/polymorphism.
>An important point - there was a concidence of structure within which natural
>selection works.

In what way is there coincidence of structure between four different
families of butterflies, two of moths, two hemiptera, three coloeoptera,
one orthoptera, one homoptera, and five hymenoptera that are all part of a
mimetic complex? These represent a vast array of different organisms with
great genetic differences between them, yet somehow they all end up
resembling one another. The only common factor here is the predators, i.e.,

>>The lack of positive effects of genomic modifications (observed or
>>induced in the lab for 100 years) is probably the reason why
>>so many people are not convinced by the classical approch of
>I agree. perhaps labs are not the best way to look at evolution. And
>perhaps the
>wrong kind of evolutionary framework is being applied.

Or perhaps everyone has forgotten that one of the main lines of evidence
used by Darwin was human-directed breeding of domestic plants and animals.
Are you claiming that no new plant or animal breeds have been developed in
the last 100 years? These are all quite excellent examples of visible
positive effects of genomic modifications, and I cannot imagine how one can
ignore them. Of course, whether you consider the transformation from a wolf
to a Pekingese to be a *positive* effect is a matter of opinion. ;-)


Doug Yanega    Depto. de Biologia Geral, Instituto de Ciencias Biologicas,
Univ. Fed. de Minas Gerais, Cx.P. 486, 30.161-970 Belo Horizonte, MG   BRAZIL
phone: 031-449-2579, fax: 031-441-5481  (from U.S., prefix 011-55)
  "There are some enterprises in which a careful disorderliness
        is the true method" - Herman Melville, Moby Dick, Chap. 82

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