Would you like to see a real, live wooly mammoth? Or how about a Tasmanian tiger in the flesh? Scientists have already finagled a few ways to resurrect extinct species from their evolutionary graves. Even muckier than the scientific methods themselves, though, are the social, ethical and legal ramifications of so-called de-extinction.
In Science today, two Stanford researchers tackle this tricky topic to parse out exactly what we have to gain and lose from de-extinction technologies. Using the passenger pigeon as a thought experiment, another paper in the same issue looks at the fears and excitement of leaders in the field of genomics.
There are three main ways of bringing back extinct species, according to the Stanford researchers: backbreeding, genetic engineering, and cloning. With backbreeding, scientists use a living species that is genetically similar to the extinct species, and selectively breed it for the traits of the now-extinct species. Genetic engineering depends on existing DNA samples of the extinct species; scientists could bring them back to life by targeting and replacing specific genomic sequences in a closely-related living species. Finally, if viable cell nuclei from the extinct species are available, it can be cloned using a technique called somatic cell nuclear transfer — a tested but as-of-yet unsuccessful method for extinct species.
Based on the current state of the science, the Stanford researchers distill de-extinction down to five pros and five cons:
Benefits of De-Extinction:
Scientific knowledge: De-extinction could offer insights into evolution and natural resources that are currently unavailable to us.
Technological advancement: De-extinction could be a big step forward for genetic engineering.
Environmental benefits: Threatened or damaged ecosystems could be restored with the help of certain now-extinct species.
Justice: If people pushed plant and animals species into extinction, perhaps we owe it to these species to try and bring them back.
Wonder: How cool would it be to see extinct species alive and kicking again?
Objections to De-Extinction:
Animal welfare: People could be exploiting animals for solely human purposes, and may cause individuals of the de-extinct species harm.
Health: Species could carry retroviruses or pathogens when brought back to life.
Environment: De-extinct species would be alien and potentially invasive; their habitats and food sources have changed, so their roles in these changed ecosystems could be too.
Political: De-extinction may change priorities in other fields of science, such as medical research and the conservation of currently endangered species.
Moral: Is de-extinction playing god, or just plain wrong? It may also have unforeseen consequences.
If an extinct animal were brought back to life in the lab, the authors point out that it would still lack many of a species’ key characteristics, such as epigenetics, environment and social groups. Plus it would bring along with it a number of complicated legalities relating to the Endangered Species Act and patent laws. And that doesn’t even get into the messy world of if and how such resurrections should be regulated.
In the end, both papers seem to draw open-ended conclusions. But if the practice is really as inevitable as it seems, the authors say the most interesting part will be seeing how humanity reacts.