Ernst Mayr: Where Are We (1976)



Ernst Mayr: "Evolution and the Diversity Of Life" pages 309- 310,
Harvard University Press 1976

"The emphasis in early population genetics was on the frequency of genes
and on the control of this frequency by mutation, selection, and random
events. Each gene was essentially treated as an independent unit
favoured or discriminated against by various causal actors. In order to
permit mathematical treatment, numerous simplifying assumptions had to
be made, such as that of an absolute selective value of a given gene.
The great contribution of this period was that it restored the prestige
of natural selection, which had been rather low among the geneticists
active in the early decades of the century, and that it prepared the
ground for a treatment of quantitative characters. Yet this period was
one of gross oversimplification. Evolutionary change was essentially
presented as an input or output of genes, as the addition of certain
beans to a beanbag and the withdrawing of others. This period of
"beanbag genetics" was a necessary step in the development of our
thinking."

The next advance was characterized by an increasing emphasis on the
interaction of genes. Not only individuals but even populations were no
longer described atomistically as aggregates of independent genes in
various frequencies, but as integrated, coadapted complexes. A gene is
no longer considered to have one absolute se1ectiye value but rather a
wide
_range of potential vales that may extend from lethality to high
se1ective superiority, depending on genetic background and on the
constellation of environmental factors.

Let me try to place this new development into a historical perspective
and determine its relationship to the preceding period. There is no
doubt that the classical period of population genetics was dominated by
the mathematical analysis and models of 'Fisher (1930), Wright (1931)
and Haldane (1932). All these authors, although sometimes disagreeing
with each other in detail or emphasis, have worked an impressive
mathematical theory of genetical variation and evolutionary change. But
what, precisely, has been the contribution of this mathematical school
to the evolutionary theory, if I may be permitted to ask such a
provocative question? (see also Lowontin 1971). Some of the younger
evolutionists, perhaps not too well acquainted with the earlier
literature, have ascribed to this school many of the major components of
the modern synthetic theory of evolution. Others, like Waddington
(1957), have questioned the magnitude its influence."

JE:-
Given the empirically true fact that all genomic gene fitness in nature
remain epistatic and therefore 100% dependently selectable whereas the
opposite is assumed within population genetics oversimplified models
that have ended up providing evolutionary theory with everything from
Haldane's (false) Dilemma to Hamilton's heuristic rule that was misused
to determine when organism fitness altruism could evolve in nature,
where are we now in 2005? Why hasn't a theory of heritable epistatic
gene fitness been developed allowing a minimally VALID simplified model
of TWO loci with two alleles that are dependently and not independently
selected at the empirically true, single, fertile organism level of
selection?

Regards,

John Edser
Independent Researcher

PO Box 266
Church Pt
NSW 2105
Australia

edser@xxxxxxxxxx








John Edser
Independent Researcher
PO Box 266
Church Pt
NSW 2105
Australia

edser@xxxxxxxxxx





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