Genetic diversity and evolution

Abstract

Estimation of the amount of genetic variability in natural populations of living organisms is of such great interest that sharply divided opinion on the outcome of such estimation existed even before any reliable method of estimation was available. The biochemical technique of enzyme electrophoresis has revealed an unexpectedly high level of genetic variability in a variety of organisms. This technique suggests that organisms may be heterozygous for 6 to 15% of their loci and 15 to 50% of the loci may be polymorphic in any population. The more recent technique of DNA restriction fragment length polymorphism (RFLP) has confirmed such high levels of genetic variability. The debate now concerns, how such a high level of genetic variability is maintained. The nature of this debate is bound to have profound implications, both for evolution and for conservation. Besides, recent discoveries in eukaryote genetics are likely to upset many of our traditional views about the genetics of evolution, and hence about its relevance for conservation.