Day By Day

Thursday, June 19, 2008

Oh, the Humanity!

At the World Science Fest an expert panel debated the question of "What It Means To Be Human". Not surprisingly, they couldn't agree on an answer. John Hawks, an anthropologist and evolutionary biologist, suggests a solution.

First of all, Hawks disagrees strongly with the idea, advanced by the expert panel, that we are all basically the same under the skin and that human differences are essentially environmental in origin rather than intrinsic. He asserts that genetic differences among humans are large and that evolutionary change is continuing.

He further asserts that because of the wide range of human differences no rigorous definition of humanity is possible. Any such definition would exclude some categories of human while including some categories of being that are definitely non-human.

He writes:

For some reason, nobody ever thinks about humanity in a very inclusive sense. The wheelchair-bound are no less human just because they do not walk bipedally. Children with severe mental defects, or physical abnormalities are not less human, even if they do not develop into independent adults. People in different parts of the world are not more or less human than each other, despite their manifest genetic variety. A lack of speech does not make one subhuman. Not even a lack of parenting and socialization can do that: "Feral children" and other extreme cases of neglect are still human. And there are many people who not only will not "mate and produce fertile offspring," but are physically incapable of mating with another person. Yet they are human.

People clearly want to define humans in terms of some phenotype -- generally some socially valuable phenotype. Often they talk about "consciousness" -- without considering whether they would deny the humanity of the unconscious -- or grant humanity to the first conscious machine. Less often, people want to define humans in terms of some genotype. This effort never goes so far, because the genes that we know the most about tend to vary among people!

So what, then, do all humans share? According to Hawks it is our common evolutionary history.

One thing is shared by all humans, and cannot be taken away: our evolutionary history. Each of us bears some -- but none has all -- of the marks of this history.

It is our history that connects us to our distant relatives, not our genes. Even with a close relative like a twentieth cousin, there is a decent likelihood that you will share no genes at all because of your shared kinship from your most recent common ancestor. By the fiftieth generation, it is a virtual certainty. You are a genetic stranger to your ancestors.


Only history defines humanity, and will continue to define us no matter what we become in the future.

Read the whole essay here.

Interesting, and to an historian, persuasive. Hawks frequently gives me things to think about, that's why I keep coming back to his blog.