I have a minor point of contention with the author, namely that he slightly exaggerates the advances and insights of the Muslim scientists and philosophers. I find this understandable, but unfortunate, since when such exaggerated claims are debunked, it makes one suspicious of all such claims. I've written about this before. For example, there was an article a couple of years ago about 20 Muslim inventions that Western civilization used. When you look at it, however, it turns out that almost none of the inventions were actually made by Muslims. After this, one could be forgiven for taking similar claims with a grain of salt.
The article in particular begins with a foreshadowing of Darwin's theory of evolution on the part of a fairly obscure 9th-century author named al-Jahith, who wrote
Animals engage in a struggle for existence; for resources, to avoid being eaten and to breed. Environmental factors influence organisms to develop new characteristics to ensure survival, thus transforming into new species. Animals that survive to breed can pass on their successful characteristics to offspring.
I think this is an interesting passage, but it's not as impressive as the article implies. For one thing, any agrarian society knows that animals compete in a struggle for existence, and that they vary in ways that make their individual survival less or more likely. I'm more impressed by al-Jahith's claim that "new characteristics" arise; but Jews and Christians had already been claiming for centuries that the various differences among human ethnic groups arose after humanity's creation. So it doesn't strike me as a revolutionary claim.
Darwin's genius did not lie in pointing to a struggle for existence (natural selection); rather, it was his application of it. Others had looked at this struggle as something that accounted for the diversity within a species (or natural group). Darwin used it to account for the diversity across species as well; in fact, it accounts for the origin of the species in the first place. Al-Jahith's quote simply doesn't address this.
A view that strikes me as being closer to Darwin than al-Jahith's comments is the doctrine of rationes seminales, or seminal principles, that was conceived by the ancient Stoic philosophers, and was accepted by many early Christian philosophers before the advent of Islam, such as Athenagoras, Tertullian, Gregory of Nyssa, and Augustine. This position held that God created the world in "seed form" or with certain potentialities which then unfolded or developed.
This may sound harsher than I intend it; the article is very good overall, and his exaggeration is slight. He even points out that al-Jahith's comments seem to be derived from folklore rather than scientific observation. So I recommend it.
(cross-posted at OregonLive)