The spring 2019 issue of The Claremont Review of Books has an essay by David Gelernter entitled “Giving Up Darwin” that summarizes some of the arguments against Darwinian evolution as developed by proponents of “intelligent design” theory at the Discovery Institute. Gelernter is silent about the many objections to these arguments, and thus he conveys to his readers the impression that these arguments are irrefutable. Actually, the arguments are so weak as to be easily refuted.
THE ORIGIN OF SPECIES
THE CAMBRIAN EXPLOSION
THE EVOLUTION OF BODY PLANS
The differences between animal species come not from differences in their "tool kit genes" but differences in their "genetic switches," which are devices in DNA that tell tool kit genes when, where, and how to act. The gene controlling the formation of a fly's wing is the same as the gene controlling the formation of a human arm. The difference arises during embryonic development as regulatory genes turn the other genes on and off at different times and places in the body.
The beauty of this explanation is that it allows us to explain the origin of new species. Small changes in the timing and pace of these genetic switches can lead to the evolutionary development of new species. So, for example, a fish with fins can evolve into a fish with primitive legs for crawling onto land, when small changes in the genetic switches move from creating fins to creating legs.
This same evolutionary mechanism can explain what makes us uniquely human, with our human capacities for thinking, feeling, and acting. Our human uniqueness depends on the uniqueness of our brains in their size and complexity. The evolution of those brains from smaller and simpler primate brains could arise from evolutionary changes in the genetic regulation of the development of primate brains and nervous systems.