Natural Selection

HISCOX at IRAD.AFRC.AC.UK HISCOX at IRAD.AFRC.AC.UK
Fri Jun 11 09:08:00 EST 1993


RE: NATURAL SELECTION AND JUMPING EVOLUTION

      Randall made a very good point in that there are many theories
concerning evolution-from Lamarkism to Creationists non of which have been
definitely proved or discounted. One point that might be made with Gould's
punctuated evolution theory is that (and I think) this hypothesis was based
on the observed changes in snail morphology through time discovered in the
Kooba Fora (probably wrong spelling) bed. Comparing morphology with geological
time did indeed reveal that morphological change 'jumped'. However, when
morphological change is plotted against biological/generation time (snails
reproduce on average twice a year) the 'line' becomes straight-admittedly with
gaps, probably due to an incomplete fossil record. Thus evolution could still
occur with gradual changes rather than leaps.

      On the subject of four winged Drosophila flies, do these flies survive
to reproduce when in competition with the two winged variety, and does anybody
breed these flies, if so is it possible to have some?


Julian A Hiscox

E-mail: HISCOX at UK.AC.AFRC.IRAD



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