Scientists Saving Species: One Gene at a Time

A Florida panther. One of the animals that was aided by "facilitated adaptation," Michael Thomas's technique for combating the extinction crisis. Photo courtesy of nature.com.

With the changing climates and shrinking biodiversity worldwide, scientists have begun to seriously consider alternative, ethically debatable methods as means to save endangered species.

Currently, conservative estimates say that 15-40% of species alive today will be extinct by 2050 due to climate change and loss of habitat. In her book Frankenstein's Cat, Emily Anthes further breaks down this estimate. She writes that 25% of mammals, 33% of amphibians, and 12.5% of bird species are in danger of extinction. Compare this with the steadily and rapidly increasing population of humans, which is expected to be around 9 billion in 2050. The increase in human population will no doubt only worsen the extinction crisis and push more and more animals near or onto the endangered species list.

A panda. One of the animals which makes up part of
the 25% of mammals in danger of becoming extinct.
Photo courtesy of nbcnews.com.

In an article in the journal Nature, Michael Thomas and his co-authors explore the use of what they call "facilitated adaptation" (a method of rescuing a population by introducing it to adaptive alleles or gene variants, with the help of genetic engineering) to prevent the alarming predications of extinction from becoming reality. 

Facilitated adaptation can work in three different ways: (1) better-adapted populations of the same species can be crossed with threatened populations in introduce more desirable alleles into the threatened population, (2) genes form well-adapted populations could be inserted into the DNA of threatened populations of the same species, or (3) genes from well-adapted species could be incorporated into the genetic code of a different, endangered species.

According to Thomas, each approach comes with different risks and challenges to overcome. For example, in the case of transferring alleles that would code for things such as increased tolerance of warmer temperatures or resistance to diseases, potential risks are the introduction of new diseases to the threatened population and the possibility of harming the threatened populations by disrupting co-adapted genes (if one gene is injected and it changes the function of another gene in the threatened species, this could have a cascade effect in the species, and the result may not always be positive).

However, in some cases the possibilities for positive outcomes would outweigh the risks.

The Puma concolor coryi, an endangered species of Florida panther, is just one of the success stories that has risen from the use of facilitated adaptation. In this case, a better-adapted species (the Puma concolor stanleyana from Texas) was introduced into the Florida panther's environment. By introducing just eight cats from Texas, the population of Florida panthers rose 100%.

A rainbow trout. Scientists found a gene that yields
increased head tolerance, a contender for a gene
to be transferred to endangered fish populations.
Photo courtesy of beekman1802.com

The third option for facilitated adaptation (transferring genes from well-adapted species to different, endangered species), has been used in plant agriculture for years in order to improve crops' resistance to drought and extreme temperatures. For example, genes from rice plants have been used to make tomato plants more tolerant to cooler temperatures.

Scientists have since been able to identify genes in different animals that would be contenders for transfer to a number of endangered species. Earlier in 2013, researchers identified alleles in rainbow trout that are associated with heat tolerance. These favorable genes could be inserted into embryos of fish populations that are severely threatened by the rising water temperature brought about by global warming.

Anthes leads the discussion of saving endangered species away from facilitated adaptation, and towards an equally (if not more-so) controversial solution: cloning.

She introduces Betsy Dresser, the chairperson of ACRES research lab in New Orleans, where scientists (similar to Thomas and his co-authors) are working to solve the extinction crisis through the exploration of the option of cloning.

Anthes proclaims that while cloning is by no means advanced enough to overcome a number of complications that arise from it, the possibility of saving endangered or even already extinct species is a compelling enough rationale to attempt it.

One of the huge advantages of cloning is that it doesn't require invasive procedures. Even skin cells can be used to make a clone of an animal. That means that already threatened species would not have to undergo potentially risky surgeries to retrieve reproductive cells from females. It also means that old, inviable, or even dead animals could be utilized to save the species.

Both Anthes and Thomas agree, however, that their tactics alone will never be enough to completely halt the extinction crisis from occurring. Each of their propositions are merely a tool in the equation. Conservation of habits is another huge part of this equation. Without the preservation of animals' habitats, no amount of genetic engineering can prevent their extinction.


References:

Thomas, Michael A., Gary W. Roemer, Josh C. Donlan, Brett G. Dickson, Marjorie Matocq, and Jason Malaney. "Ecology: Gene Tweaking for Conservation."Nature 501.7468 (2013): n. pag. Nature.com. Nature Publishing Group, 25 Sept. 2013. Web. 11 Oct. 2013.

Anthes, Emily. Frankenstein's Cat: Cuddling up to Biotech's Brave New Beasts. New York: Scientific American/Farrar. Straus and Giroux. 2013. Print.