Genetic modification of animals so that they can deal with changing climate and habitats may be the only way to save some of the most endangered species from becoming extinct, according to biologists who want to start a debate on how to stem species loss.
Biologist Michael Thomas said conservationists needed to debate what he and his colleagues called “facilitated adaptation”, which involved rescuing populations or species by introducing gene variants that allow them to survive in changing temperatures or different ecological niches.
“Even the most conservative estimates predict that 15–40% of living species will be effectively extinct by 2050 as a result of climate change, habitat loss and other consequences of human activities,” wrote Thomas, of Idaho State University in Pocatello, and his colleagues in a comment article for the journal Nature.
This could happen in several ways. Animals from a threatened population could be hybridised with individuals from the same species that were better adapted to a new environment. Or, if scientists could identify the genes that made one population more suited to an environment than another, they could insert those genes directly into the less-suited populations or individuals.
The most extreme (and most likely controversial) idea proposed by Thomas is to take genes from a well-adapted species and insert them into the genomes of endangered individuals from completely different species.
Such transgenic organisms are already common in plants – genes from the cress plant Arabidopsis have been used to engineer tomato plants so that they can more easily tolerate low temperatures.
“Today, 12% of arable land worldwide is planted with genetically modified (GM) crops; the GM seed market alone is valued at US$15 billion,” Thomas wrote. “We believe that these combined factors mean that conservationists will almost certainly be tempted to apply genetic engineering to safeguard biodiversity.
"Facilitated adaptation might be less logistically challenging than moving entire populations, and less fraught with ecological and socio-economic complications — relocation could introduce harmful invasive species, for example, or unleash outbreaks of disease.”
Scientists have already inserted genes from the Asian chestnut tree into its American cousin to make the latter less susceptible to disease, and their plan is to release the genetically-modified seeds across the US.
Kate Jones, a professor of ecology and biodiversity at the Centre for Biodiversity and Environment Research at University College, London, said Thomas’s ideas had merit, but conservationists needed to tread carefully in legal, ethical and practical terms.
“[It is] important to think about priorities – which species would benefit from intervention the most?”
She said the gene-manipulation techniques being developed by synthetic biologists should be studied more closely by conservation biologists anyway, to see where they might be useful.
Thomas acknowledged there were many unknowns in the proposals that “could bring unintended and unmanageable consequences” and therefore argued that the ideas needed research from a mass collaboration of ecologists, climate scientists and molecular biologists, among others, to begin mapping out the possibilities.
“Facilitated adaptation will also require a change in people’s views about biodiversity conservation and its ethics, practices and impact on society,” Thomas wrote. “For some species, [it] could turn out to be the only viable remedy."