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PARTISAN REVIEW
Organic evolution.
Just as was the case for the other three deep prob–
lems, the first big breakthrough towards an eventual solution of the
enigma of the origin of species came in the middle of the nineteenth cen–
tury, when Charles Darwin presented his theory of natural selection. By
mid-twentieth century, classical Darwinian theory had been given a
sharper formulation by the "New Synthesis" of neo-Darwinism, which
brought the quantitative concepts of mutation rate and population genet–
ics to bear on organic evolution. Some modifications of neo-Darwinian
theory became necessary, however, in the latter part of the twentieth cen–
tury, upon the application of the insights of molecular genetics and
embryology to the explanation of evolutionary processes. Prominent
among these latter-day insights was the realization that most historical
changes in molecular evolution at the level of DNA were neutral with
respect to the Darwinian "fitness" concept and are attributable mainly to
stochastic rather than selective processes. Molecular evolution thus came
to be distinguished from morphological evolution at the level of gross
phenotype, at which natural selection does playa major role.
The unsolved biological problems happen to be the most difficult, for the
not surprising reason that the easier problems are always solved before the
more difficult ones. The deepest ptoblem connected with organic evolution,
the very origin of life itself, still lacks a credible, coherent proposal for its
solution. Perhaps, as a historically unique event that left no traces, the ori–
gin of life may be intrinsically insoluble. Despite its obvious importance
(and the certainty of a Nobel Prize for its solution), few biologists are work–
ing on the origin of life, probably because of its seeming intractability.
Probably the deepest of unsolved biological problems, and hence,
according to the deep heuristic principle promulgated in the preceding
paragraph, destined to be the last of them, is the consciousness provided
to us by our brain.
In
fact, until recently, the problem of consciousness
appeared so deep that it seemed to be a philosophical rather than bio–
logical matter. One reason usually advanced for excluding conscious–
ness from the realm of biological problems is the subjectivity of the
experiences it provides, or what the philosopher John Searle referred to
as "first-person ontology." The subjectivity of conscious experiences is
reflected in some of their qualitative aspects (or "qualia"), such as the
redness of the setting sun or the salty taste of sea water, which cannot
exist in the absence of a conscious living observer. This argument con–
trasts the subjectivity of consciousness with the objectivity, or "third–
person ontology," of such natural phenomena as the spectral attributes
of the light of the setting sun or the salt concentration in sea water,
which can (and did) exist even in the absence of any living creatures.
