Dead as a Dodo?

Teresa MacDonald,
Director of Education
KU Natural History Museum
and Biodiversity Research Center


Dodo

Dodo head

The whole dodo

(Department of Special Collections, Spencer Research Library)


Extinction is a powerful word. Our curiosity is piqued when we hear about long extinct species and the reasons they have disappeared. We want to know what happened to the monsters that lived thousands and millions of years ago. Recent extinctions and the declining diversity of life are regular news items. The growing list of extinct species and the warnings of the imminent extinction of endangered or threatened species are cause for concern.

Why are we as a species so interested in the fate of other animals? First, let's think about what extinction means. It means that every single member of an entire species has died. We declare something to be extinct when it is either only known from fossils or has not been seen for a long time — as had been the case with the ivory-billed woodpecker, when its previous confirmed sighting was more than 60 years ago.

Either way, the result is the same: There are no more left, zip, zilch, nada — all gone. That is pretty much that then, isn't it? Maybe not. There is always the chance that we made a mistake. Plants and animals, such as the coelacanth (a deep sea fish) and the ivory-billed woodpecker, once thought extinct, have been rediscovered. Maybe the rest are really good at hiding, or we are just looking in the wrong place. And, even if they are all gone, a tantalizing possibility exists of bringing them back.

Bringing back extinct organisms, through the use of cloning, is a staple of science fiction — preferably bringing back a large carnivore that can wreak havoc in a small town in Middle America. This kind of cloning is the creation of a genetic replica: making an identical twin of an extinct animal using ancient DNA. DNA is the chemical code found in the cells of living things. It carries information for the structure and development of an organism. In principle, it is simple to create such a replica animal. You just need its DNA. Once you have that, you put it into another animal's cell that has had its own DNA removed, implant the doctored cell into an animal to develop and TA-DA!

Researchers, despite problems, have successfully cloned various animals including sheep, frogs, cows, cats, monkeys and dogs. But how about cloning extinct animals — can we get DNA from their remains? Yes: DNA has been extracted from the teeth, bones and skins of extinct organisms: the thylacine (Tasmanian tiger), cave bear, quagga (an extinct member of the horse family) and giant lemurs.

But we don't yet have a baby quagga. DNA is fragile and the ancient (and even not-so-ancient) DNA we have extracted so far is damaged and incomplete. We need to figure out how to put the pieces together and fill in any missing information. Even if we had dinosaur DNA, we don't have a dinosaur cell with all its parts to put it in. This means that if we use a cell from a modern relative and not the extinct species, and if we use a modern animal's DNA to fill in gaps, then what we get will be a trans-species clone. Whatever we may be able to reconstruct, it will not be the creature that existed before, but rather a chimera — a composite of more than one species.

Let us suppose that all the technical hitches can be worked out — that we can get complete DNA or reconstruct the missing information for an extinct species, and even recreate or recover an entire cell. That leads to a whole bunch of other questions. Should we bring back a dinosaur just because we can? Species don't exist in isolation — so which ones do we bring back? Could they survive in a modern environment with different things to eat and run away from?

Besides, is extinction of a species such a big deal? It is a fundamental part of evolution: Old species turn into new species, get outcompeted, succumb to climate change or habitat loss. Species have come and gone throughout the history of life on Earth. Of all species that have ever lived, 99.9 percent are extinct.

Many recent extinctions are most likely our fault. Yet we are not necessarily evenhanded with our concern. We work to protect endangered species — particularly the warm, fuzzy ones — but at the same time take deliberate actions to eradicate others, like disease-causing bacteria and parasites. Ask yourself the question: What you would bring back?

The bottom line is having good reason to bring back the dead — and defining what "good" means in this case. Does it matter if humans directly or indirectly caused the extinction? Is satisfying our curiosity or the coolness factor enough? After all, who wouldn't go to see a dodo — or a live mammoth — if they could?

But maybe it isn't just curiosity, the promise of a visit to some Jurassic Park . . . or our sense of justice toward plants and animals we have helped to extinguish . . . or just plain concern about them. Perhaps we recognize that we could be next, and this fascination with rescuing the past is a reflection of our hope that we can save ourselves. Perhaps, in other words, we are afraid. And, if not, maybe we should be.

KU Jayhawk

Office of the Vice Provost for Research
2385 Irving Hill Road
Lawrence, KS 66045
785/864-3441

The page was last modified on Wednesday, August 24, 2005
16:08:26 PM Central Daylight Time