Darwinian Evolution is a Highly Evolved Process
J. Mitteldorf
Department of Ecology and Evolutionary Biology, University of Arizona
The 'Modern Synthesis; or 'Population Genetics' has been the standard quantitative version
of Darwin's theory for eighty years. A foundational hypothesis of the theory is that the primary
target of natural selection is immediate reproductive success. Indeed, the standard population genetic
definition of fitness refers to an increase in gene frequency from one generation to the next. But
there is diverse evidence that this hypothesis is false. The most compelling evidence comes from
the phenomenology of aging, which detracts strongly from individual fitness, and from the
implementation of genetic exchange via separate sexes, which costs a full factor of two in
individual fitness. How can it be that natural selection can strongly oppose individual reproductive
fitness? The resolution of this paradox begins with an appreciation of population dynamics.
Dependence on a common food pool ties together the fate of a population community, and creates
a powerful selective force for restrained reproduction in order to avoid unstable population cycling
and local extinctions. The full resolution involves appreciation of evolution as a highly-evolved process.
Natural selection in the short term has been shaped by natural selection in the long term, so that
dead ends such as unrestrained reproduction are consistently avoided. Programmed death and
sexual reproduction, among other less obvious features of the biosphere, exist for the purpose
of enhancing evolvability.
Homo Sapiens Liberatus Workshop, Moscow State University, May 2010