Recently on CRSnet there have been a number of posts on the
subject of probability calculations related to beneficial mutations. This
discussion then got switched to the Creationist context and one of the
messages (I forget who) asked if there was enough time, after the flood,
for the development of races in man or animals, given the time
constraints of a young earth approach. My own feeling is that one does not
have to invoke mutations at all in most cases (unless some hard genetic
evidence points that way...). I offer here a quote from an evolutionist
author discussing race evolution. In it we find presented a case of a
small random sample (for all intents and purposes) of organisms taken
from one geographic location and sent to a new one. In a short time a
large variety of stable phenotypes appear that can be identified as races.
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"Given the inefficiency of race formation when neither selection
nor isolation is absolute, just how many generations might be necessary
for the differentiation of a parent population into clearly recognizable
racial varieties ? The answer comes from studies of race formation in the
house sparrow. The founding population was introduced into America in
1852. From an East Coast zone of entry, succeeding generations have
spread west to California, south into Mexico, and north into Canada.
Populations of sparrows can now be found in damp coastal areas of
Louisiana and in the dry, hot deserts of Arizona. They thrive on the cold
northern plains of central Canada and in the heat of Houston Texas.
Today, one can demonstrate that the different geographical populations of
sparrows show characteristic differences in color, wing length, bill
length, and body weight. Using these differences as guides, more than a
dozen racial varieties of sparrows can be clearly identified. Distance
serves, substantially, even if not perfectly, to isolate breeding
populations of sparrows from each other. Environmental factors -
particularly climate - provide strong, although not absolute, selection
pressure. For example, it is known that there is a relationship between
optimal body size and climate. Cold climates tend to select for a
heavier, heat-conserving body that minimizes the surface - to - volume
ratio. Table 6-1 shows that this relationship holds for sparrows taken at
a variety of locations.
Table 6-1: Geography and Body Weight in Racial Populations of House
Sparrows.
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Locality Average Body Weight (grams)
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Houston, Texas 28.0
Austin, Texas 28.0
Los Angeles, CA 28.2
Salt Lake City, Utah 28.7
Lawrence, Kansas 29.4
Montreal, Quebec 30.4
Edmonton, Alberta 30.8
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(After Eugene Schreider, "Ecological Rules, Body-Heat Regulation,
and Human Evolution" in Evolution, 18 (1964)
Those from cold regions like Edmonton, Alberta, are the heaviest. Those
from climates like Texas and California are the lightest. Samples from
climates between these extremes have intermediate values.
Before the results of this study were published a few years ago,
evolutionary theorists assumed that more than 1,000 generations would be
necessary for racial differentiation in birds. The discovery that all
these races of birds evolved within one hundred generations came as a
bombshell. It is clear that in nature evolution at the racial level can
be extremely rapid. In a human population one hundred generations cover a
timespan of about 2,000 years. These studies suggest that given a
reasonable degree of isolation and strong selection pressure, relatively
short periods may be required for the elaboration of some racial
characteristics in man."
pp. 88-89 in Goldsby, Richard: _Race and Races._
MacMillan New York 1971 132p.
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In conclusion I would offer that the evidence seems to point in
the direction of the idea that gene pools are more flexible than we may
think and that it is not absurd, in genetic terms, to think that a small
population of individuals might give birth to a wide variety of
phenotypes (or racial types). I would also posit that the further we go
back in time, the more this may be true. We could then expect even
greater gene pool flexibility (even in small populations) among the
original "created kinds" (or baramins) and possibly, up until the Flood,
very little genetic deterioration. Possibly some of the genetic
mechanisms (such as I believe Kurt Wise mentioned) related to a number of
pre-programmed phenotypes (or races) were dormant in the original
baramins and only came into play in the unique environmental
circumstances that occured after the Flood. I think that on principle, it
would be wise for creationists to posit first of all that variety in
phenotypes and race differentiation is due to genetic flexibility rather
than mutations UNLESS hard genetic evidence points in the other direction.
Paul Gosselin