Battling Extinction though the Chimera
From the Animal Worlds photo essay, the phrase, "a mixture of genetically different tissues", and the image of a human/pig hybrid reminded me strongly of another image I've seen in connection with both animal worlds and extinctions, my own topic. This image shows a mouse embryo which has had DNA from the extinct thylacine (Tasmanian Tiger) inserted into it.
The thylacine DNA was tagged with a blue-green marker. Therefore everything blue-green in the mouse is the DNA of an extinct animal being expressed in a living one. For science, this is an amazing leap forward, and the mouse/thylacine chimera represents real hope that the extinction of the thylacine (and other animals) may not be permanent.
However, how animal worlds presents the chimera forces us to look at this leap of science from an ethical perspective. The embryo was killed before it developed much further, in accordance with ethical guidelines surrounding vertebrates, but there is still a dilemma here. After all, this mouse was injected with foreign DNA that interfered greatly with its own, purely for a science experiment it would never have been able to survive, all so scientists would know whether DNA from a dead animal was viable and able to replicate and express.
In this light, the fate of the mouse seems ethically dubious, but there is another factor to consider. We, as a species, killed the thylacine. We systematically hunted it to extinction for the false accusation of sheep-killing (evidence suggests that Tasmanian tigers were actually pounce-predators who targeted prey weighing 1-5kg, and therefore unlikely to target sheep). So the question is this: do we, as the ones responsible for its extinction, have a moral obligation to the thylacine to do everything we can to bring it back? And if we do, does this moral obligation justify the ethical dubiousness of creating chimeras and using surrogates of another species?
ABC News, "Tasmanian tiger DNA comes alive in mouse", http://www.abc.net.au/news/2008-05-20/tasmanian-tiger-dna-comes-alive-in-mouse/2441920.
Jones, M. E. and Stoddart, D. M. (1998), Reconstruction of the predatory behaviour of the extinct marsupial thylacine (Thylacinus cynocephalus). Journal of Zoology, 246: 239-246. doi:10.1111/j.1469-7998.1998.tb00152.x.
