Professor Dawkins’s great intellectual conviction is that evolution is progressive, and tends to lead to more and more complexity. Species, in his view, often arrive at similar solutions to evolutionary puzzles — the need for ears, eyes, arms or an octopus’s tentacle. And, often although not invariably, bigger brains. So the saber-toothed tiger shows up as a cat in Europe and Asia, and as a marsupial in South America. Different species seized on the same carnivorous solution. (He most certainly does not, however, view evolution as progressing toward us, that is humans — were we to disappear, some other species most likely would fill our evolutionary niche.) ...Evolutionists have endless debates over whether birds are descended from dinosaurs, whether humans mated with Neanderthals, and many other issues. These may be decided by more fossils and better data. But what is really striking is that their leaders disagree about the core issues of the theory. For example:
His theory of progressive evolution, it should be said, is controversial. Professor Dawkins had a single great rival in writing about evolutionary biology: Stephen Jay Gould of Harvard.
Professor Gould, who died in 2002, was adamant that evolution was contingent — that while a species might progress in leaps and bounds, it was equally likely that it might reach a dead end, or regress. If a meteorite hit Earth and destroyed all intelligent life, he argued, the chances are vanishingly small that complex, intelligent life would evolve again.
As the writer Scott Rosenberg put it, Professor Gould saw our species as “simply a tiny accident occurring on a minor side-branch of the evolutionary tree.”
Whether evolution is progressive or contingent.
Whether evolution is driven more by random mutation or natural selection.
Whether evolution is gradual or punctuated.
Whether evolution is entirely selfish genes or includes group selection.
Whether evolution is compatible with Christianity.
Whether evolution is linked to a political and moral worldview.
They agree that evolution causes changes in gene frequencies from one generation to the next. Yes, that is obvious. But I don't see how it can be much of a theory unless it can answer bigger questions about what the theory is.