The Overlap Feature of the Genetic Equidistance Result—A Fundamental Biological Phenomenon Overlooked for Nearly Half of a Century

Abstract

The genetic equidistance result shows that different species are approximately equidistant to a simpler outgroup in protein sequence similarity, as first reported by Margoliash in 1963. This result, together with those of Zuckerkandl and Pauling in 1962 inspired the molecular clock and in turn the neutral theory of evolution. Here it is shown that the clock/neutral theory had from the beginning overlooked another characteristic of the equidistance result, the overlap feature, which shows a large number of overlapped mutant amino acid positions where any pair of any three species is different provided that the species concerned differ from one another in complexity as a result of macroevolution. In contrast, when simple organisms of similar complexity and short evolutionary divergence are compared, there are only a small number of overlaps largely consistent with chance or the neutral theory. The full reality of the equidistance result strongly supports the Maximum Genetic Diversity hypothesis, a more complete account of hereditary changes.