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Sunday, March 24, 2013

De-extinction: Let's tamper with those forces we don't understand

by John MacBeath Watkins

Mama was a chicken, daddy was a rolin' stone.

Jack Horner wants to breed a chicken with dinosaur characteristics -- teeth, a long tail, arms, hands with claws, the whole works.

Of course, it means tampering with forces mankind does not fully understand. That's because he's a scientist. If he was tampering with forces mankind has written manuals about, he'd be an engineer.

And Horner's not the only one. There's an effort under way to bring back the passenger pigeon. We've got plenty of DNA, and it's not very old, because the last of the species died out only a century ago. There's a closely related pigeon whose DNA can be used to supplement the DNA we've got.

Some folks in Europe are trying to back-breed to the aurochs.the ancestor of cows, which has been extinct since 1627. Since we have plenty of cows, that's mainly a matter of  breeding back to aurochs characteristics. A couple of Germans associated with the Munich zoo attempted this in the 1920s, and the result was a hardy breed called Heck cattle. They are smaller than the aurochs, but look like them.

The new effort can use the DNA of the aurochs and modern cattle to find the actual genetic makeup of the extinct species that has survived in its modern descendents, rather than rely on visible characteristics.

Are we playing God when we attempt such things? Well, most biologists are atheists, so they don't think that's possible, but they are alive to the notion that there are ethical issues to be addressed. But here's another aspect: Haven't we already played God in wiping various species from the face of the earth? Well, granted, we didn't do it because they were sinful, and we didn't tell them to build an ark or leave and not look back on pain of being turned into a pillar of salt, but that just shows we're less merciful and less rational than God.

The ethical questions have more to do with the question, what's in it for the animals involved?

Some techniques involve making animals with reproductive organisms that will produce a different animal entirely -- chickens with passenger pigeon gonads, for example. I'm not sure this is a problem for the chicken, who would live, mate, and reproduce in much the same way it would have with chicken reproductive organs.

But sometimes, the outcome isn't certain. A Pyrenean ibex cloned in an attempt to bring back the extinct species was born with malformed lungs and died after only 10 minutes of life. The science is imperfect -- that's part of what makes it science -- and perhaps the results will impress future scientists only about has much as Heck cattle.

And once we've brought back the obvious candidates -- mammoths, dodos, and other picturesque and recently extinct breeds -- we'll start going farther afield. How long until someone tries to bring back Neanderthal man? Or even homo heidelbergensis, the last common ancestor of homo sapiens and Neanderthal?

That's where it gets complicated, because we consider human beings ethically different from animals, and cloning humans prior to homo sapiens challenges our distinctions about what it means to be human. If they prove capable of anything we are, we won't have a problem calling them human, I'm sure, but what if they are somewhere between our capabilities and those of our simian ancestors? I don't picture us putting them in a zoo, where they would essentially be as much a freak show as Jack Horner's dinochickens.

This wants thinking about. Here's a TED talk on the subject, which I found via The Long Now Foundation 


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