Make your own free website on Tripod.com
Discussion between Lodge &   Musgrave
Arthur S. Lodge     |     home
Melanism via NDT?
Discussion between A. S. Lodge & Ian Musgrave


Lodge 1:

According to Lee Spetner ("Not by Chance", Judaica Press, 1998, pp. 67, 177), there is no evidence that random mutations have played any role in industrial melanism.

Musgrave 1:

Spetner's claim is actually a misunderstanding of a paper by Bishop and Cook (1975). These authors do not claim, nor produce any evidence that random mutations are not involved. Indeed they specifically refer to mutations being involved. The role of mutation is well established in industrial melanism (see Majerus 1998, and references therein).

Lodge 2:

Dr Musgrave did not state exactly which statement in Bishop & Cook was misunderstood by Dr Spetner.  The question is not whether mutations are involved but whether random mutations are involved, as assumed in the NDT. I can find no discussion of random mutations in Bishop & Cook (1975) or in Majerus (1998); {there are many pages of references in Majerus (1998) - I have not looked them up}. It follows that neither reference shows that the NDT is applicable to peppered moth melanism.

Moreover, Dr Musgrave's statement "These authors do not claim, nor produce any evidence that random mutations are not involved" has no relevance to my statement that "there is no evidence that random mutations have played any role in industrial melanism". Dr Musgrave's statement might carry weight with someone who believed that the NDT was always applicable unless there was evidence to the contrary.

References:

J. A. Bishop & L. M. Cook, Scientific American 232 (1975), 90-99.
M. E. N. Majerus, Melanism: Evolution in Action, (Oxford University Press, 1998)