Curiosity Resurrected the Cat – Scientists Contemplate Recreating Extinct Species


By Andrea Teagle     09-Mar-2013 18:42 UTC+02:00

Andrea Teagle – The Tasmanian Tiger has been extinct since 1930. Yet curious scientists may be on the brink of finding ways to see these and other extinct animals roam the earth again. A public Ted xConference of scientists and conservationists is scheduled to take place at the National Geographic headquarters in Washington next week, sweeping discussions of genetic experimentation out of laboratories and into the public domain.

In an early effort to recreate the extinct passenger pigeon, Ben Novak of Revive and Restore – an organization set on achieving ‘un-extinction’ – has already sequenced DNA taken from a preserved museum specimen. The next step, says Harvard University DNA sequencing expert George Church, is to alter the genome of a related species, using letter-by-letter gene replacement techniques, to resemble those of the extinct species.

The difficulty of reviving extinct species by conventional cloning is that DNA begins to decompose shortly after the animal dies (cloning requires the nucleus of an egg to be replaced by the nucleus of a cell belonging to another animal). Thus the further back an animal became extinct, the less likely it is that intact cells still exist. Imagine then, the excitement of scientists when cells of wooly mammoths – another popular candidate for ‘un-extinction’ – were discovered in East Russia in August last year, perfectly preserved in permafrost.

It is easy to understand the temptation of scientists to try to revive wooly mammoths and Tasmanian tigers. But what is the justification? What might be the unintended consequences of reintroducing species long gone? Some argue that we should focus on using DNA-related technology to keep endangered species from extinction- for example, our rapidly depleting rhino population- rather than try to ‘bring back’ the dead. For some, biotechnology has a place. Others maintain that cloning research is simply not morally justifiable.

There are compelling points on either side of the argument of whether –and to what extent – cloning research should continue. In favour of advancing such technology are associated medical discoveries. For example, continuing breakthroughs in treating diseases such as epilepsy, Parkinson’s and cancer have been brought about by artificially creating these diseases in mice. Transgenetic pigs have the potential to grow human organs that can be used for organ transplants. From embryonic stem cell research – which until recently involved the controversial cloning and termination of human embryos- came the first case of human heart healing in 2004.  And, recently, scientists Ingo Potrykus and Peter Beyer used genetic modification techniques to develop ‘golden rice’ which contains beta-carotene, a precursor to vitamin A, which many children in developing countries lack.

On the other side of the debate are concerns about what is often seen as ‘playing God’. Consequentialist arguments point to the suffering and violation of the animals involved, not to mention the fate of part-animal, part-human creatures that might result from transgenetic research. For these and other reasons, molecular biology research is restricted to varying degrees around the world (it is universally illegal to clone a fully-formed human being).

Regardless of ethical or legal protests, it seems to me unlikely that every curious team of scientists out there will refrain from pushing the frontiers of gene research, and recreating extinct species or overcoming the biological difficulties of cloning humans. The saying goes ‘Curiosity killed the cat’. Maybe human curiosity can revive it. But at what cost? TEDxDeExtinction conference will take place on March 15 and can be viewed live on NationalGeographic.com.


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