Re: Good mutations

John P. McKiness (
Thu, 27 Nov 1997 21:54:59 -0600

At 04:17 PM 11/27/97 -0700, you wrote:
> I am a moderator for Biola University's "Origin's Forum," and we recently
>this issue. The problem with using the resistance to malaria that comes
>from certain african genes that cause sickle-celled anemia is that the
benifit is
>nearly canceled-out by the defect of the anemia.
> The other example that we discussed was the
>set of mutations that led to africans having darker skin. The mutations
that caused
>to have a higher melanin content in their skin allowed them to better
withstand the
>effects of the sun. This trait was then spread throughout the population,
>and it is now dominant and completely infused into the community. Does
this help?
>In Christ,
>J. Arthur Alley

Just a quick note on you statements above. I believe we white folk are the
ones who need to be thankful for the mutations that lead to our light skin
because dark skin, in all likely hood, is the original condition in our
species. Higher melanin content is the norm in the tropics and subtropics.
Light skin pigmentation is the result of beneficial mutations within mid to
high latitude populations. The need for vitamin D and lower light
intensity requires less pigment (unless we can get vitamin D somewhere
else). Less pigment on the other hand would be a harmful mutation in the
tropical savanna of Africa.

Also we need to think in terms of population. In your case of sickle-cell
anemia, a population benefits by the mutation even though some individuals

Thanks be to God for all He gives,

John P. McKiness
P.O. Box 5666
Coralville, Iowa 52241 (319) 338-5605