Q: the book does lay out, in great detail, the case for evolution. what is the most compelling piece of evidence?
A: i think the molecular genetic evidence. the distribution of genes right across the animal and plant kingdoms. before you could look at anatomy—things like bird wings and bat wings and human hands—and notice similarities. nowadays you can do the same kind of thing, but in hugely more detail. for a start we have the same genetic code for all living creatures. then we have a large number of genes that are manifestly the same, but with detail differences—they look like different drafts of the same book. in extreme cases, like a human and a beetroot, it’s like the difference between matthew and luke’s gospel—clearly they tell the same story, but with different words. whereas with a human and a chimp, it’s like two different printings of matthew, with a few typos in one. so you end with a beautiful family tree of resemblance, where very close cousins like humans and chimps have almost all their genes in common. slightly less close cousins like humans and monkeys still have recognizably the same genes. you could carry on right on down to humans and bacteria, and you will find continuous compelling evidence for the hierarchical tree of cousinship.
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