Saturday, July 10, 2010

Each According to Its Kind

In my reading today of Jerry Coyne’s Why Evolution Is True, Coyne talks about how species develop, and why they don’t interbreed. Their geographic isolation from each other is a major factor. So is the fact that one specie is not attractive to another one. And, if two species like different plants, then they’re not around each other to mate.

But is Coyne saying that they don’t interbreed because they don’t want to? I thought they also didn’t interbreed because they couldn’t. Or did couldn’t develop from not wanting to over the years?

In a Seventh-Day Adventist church that I attended years ago, a know-it-all said that he’d ask evolutionists how evolution can be true, when each animal reproduces only according to its own kind. I guess his assumption was that evolutionists thought different animals were related to one another because one specie or genus mated with another specie or genus—that interbreeding was how evolution got off the ground! But I doubt evolutionists believe that.

Yet, I wonder: suppose an animal has a mutation. Can he only mate with an animal that has had that mutation? Or maybe he’s close enough to a similar animal that does not have that mutation, that he can mate with her and pass on his genes—with the mutation. Coynes does say that species can become reproductively incompatible over several years: this doesn’t happen overnight.

At DePauw University, in a class, we were discussing evolution. A biology student pointed out that the DNA of humans and monkeys is 95% similar, indicating that humans and monkeys are closely related. He remarked that, if a human and a monkey were to have sex and to produce offspring, the baby wouldn’t last too long.

I told a well-read professor about this, and he said that humans and monkeys cannot produce offspring with each other. I retorted that he has confirmed the truth of the Bible: that animals reproduce according to their own kind. He disagreed with my statement, but I don’t recall what his argument was.

When I told a few students that the professor dismissed the possibility that humans and monkeys could have sex with each other and produce offspring, one of them asked, “Yeah, but who’d want to do that?” So I guess we’re back full-circle to what Coynes said: different species aren’t attractive to each other!

I’m not an expert on animals, but I’ve heard that certain animals from the same species cannot mate with each other. It’s not the case that every male dog can mate with every female dog, for example, for there are reproductive barriers, in certain cases. What’s that do with Genesis’ statement that each animal produces after its own kind? How broadly or narrowly should we define “kind”?

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