Science & religion in the rough: why human evolution and the multitude of extrasolar planets complicate the idea that we are special.

Author:Diamond, Jared


It's a great pleasure to receive this award, and to have the opportunity to talk with you. I've realized that I'm with a kindred group here, where it's possible for me to say things and to speak from a point of view that I wouldn't dare share in another context, particularly in the United States.

So I'll use this opportunity to discuss the relationship between science and religion, a question that interests me as a scientist and that interests many for the controversy it brings.

Basic to religion is a presumed distinction between humans and so-called animals, and a presumed uniqueness of humans in the universe. But science is just our body of knowledge about the reality of the world as best we can understand it. So, what does science have to say about the foundations of religion in reality? Two areas of science are most relevant: one is evolutionary biology, which has been well understood for 157 years since Darwin's publication of On the Origin of Species; the other is astronomy.

Let's begin with evolutionary biology. Evolution is often mislabeled as a theory, but evolution of course is a well-established fact just as the earth's revolution around the sun is not a theory but a well-established fact. We've had compelling evidence for more than a century that our modern human species gradually evolved from now-extinct species that anyone would agree were animals. So we can't make a sharp distinction between humans and animals.

The human evolutionary line separated from the line leading to modern gorillas about seven million years ago, and then separated from the line leading to modern chimpanzees about six million years ago. Gradually, over the course of the last six or seven million years, various species of the human evolutionary line evolved to be more similar to us modern humans, and less dismissible as animals. But there was never a sharp break in time between humans and animals.

For most of this last six million years, there have been multiple co-existing human species, some more like us modern humans, and some more like so-called animals. It's only in the last 32,000 years since the extinction of the Neanderthals that the human evolutionary line has consisted of only one species, namely us. There has also always been geographic variation within various human species, just as there is geographic variation within most animal species, j Hence, at any given time during the emergence of modern Homo sapiens over the last 200,000 years, there were populations more like us moderns, and other populations less like us moderns and more like animals.

Also, we know that our species hybridized recently with at least two other human species now extinct, namely, with the Neanderthals and with Denisovans. Most of us today carry about 3 percent of Neanderthal genes in our genome, but when our hybridization with Neanderthals was still taking place 32,000 years ago, there were first-generation hybrids who were 50 percent Neanderthal in their genes, a second generation crossed with Neanderthals who were 75 percent Neanderthal, and another second generation that crossed with Homo sapiens who were 25 percent Neanderthal.

So, what do all these facts mean about religion's supposed distinction between humans and animals? It means that there isn't a clear distinction. There is variation in time. There is variation in space. But religions haven't incorporated that fact. If there was a god that created humans in his or her or its image as distinct from animals, when and where did that god draw that arbitrary distinction between human and animals? Was it when we became just 25 percent Neanderthal in our genes, or when we got down to 12 percent, or 6 percent, or now 3 percent?

If we modern humans get judged and sent to heaven or hell, when and where in our evolutionary history did we start to get judged? Do chimpanzees get judged? Did Homo erectus get judged? Did 50 percent and 25 percent Neanderthals not get judged while 12 percent Neanderthals did? Was it possible to have some kind of 50 percent heaven reserved for 50 percent Neanderthals? If a male chimpanzee today dies in the course of killing chimpanzees belonging to another chimpanzee clan, does that chimpanzee...

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