Challenges to Darwinian evolution
There have been
repeated scientific challenges to the theory of evolution in the past,
and the nonbelievers of evolution cite them as support for their case.
However, the scientific challenges to the theory of evolution were
technical and of a very different kind.
The modern theory of
evolution has enjoyed success by bringing together Mendelian genetics
and Darwinian evolution; although the theory has faced many challenges
from different corners, it has survived them all. These challenges have
been of two kinds: those of scientific nature that question the adequacy
of natural selection as sufficient explanation of change and those of
general nature that question the truth of evolution on religious or
other grounds.
Among the serious scientific challenges to the
theory of evolution, the foremost has come from developmental
biologists. Many developmental biologists felt Darwin’s natural
selection theory was inadequate to explain the diversity of
developmental complexity observed among organisms. Yet 150 years after
Darwin, although our notions about the fine details of mutation, gene
regulation, and selection mechanisms may have changed, no new forces of
evolution have been added to the important forces of evolution, i.e.,
mutation and selection. Many developmental biologists rightly see the
complexity of development less of a problem to the theory of evolution
and more of a challenge to their field to explain it by natural
selection (Bonner 1988).
Other similar but more technical challenges have come in the form of non-Darwinian evolution from molecular biologists (King and Jukes 1969), neutral evolution from molecular population geneticists (Kimura 1968), and from punctuated evolution or “evolution by burst” (Eldredge and Gould 1972; Gould 1977).
As these challenges have broadened our horizons and have enriched
Darwinian evolution, especially in terms of the ever-unfolding dynamics
of mutational and genomic variation (Lynch 2007),
these were not challenges to the theory itself but only to the details
of the evolutionary mechanics, i.e., about role of selection and rate of
change.
