Categorized | Imperiled Wildlife

Preserving the Genetic Diversity of Endangered Species

How can conservationists prioritize species that are already classified as endangered? The answer to this difficult question might just be hidden inside the genes of the endangered species themselves.

Conservation resources might be finite, but the threats to our natural world are not. With so many species struggling to survive, it is more important than ever for conservationists to use their limited funding in the most effective (and efficient) way possible. But how are conservationists supposed to decide which endangered species should be given top priority? In the past, the value of a species – whether economic or social – was the dominant factor when it came to directing funding. In recent years, however, the science of prioritization has become an increasingly important aspect of conservation biology1. One emerging form of scientific prioritization focuses on a relatively new way of measuring the value of a species: their genetic uniqueness.

Genetic uniqueness, also known as evolutionary distinctiveness, is a way of prioritizing species that takes into account the relationships between species groups. According to this method, a species with a lot of close relatives should not be prioritized over a species with no close relatives, which will have been designated its own branch in the tree of life. While every species is genetically unique, most species share some of their genes with their close relatives. (Just look at chimpanzee and bonobos, which share 99.6% of their DNA with each other and 98.7% of their DNA with another close relative, humanity2.) This means that species with few or no close relatives contain genes that can’t be found in any other species.

Darwin's Tree of Life

Charles Darwin’s preliminary sketches of the tree of life were some of the earliest attempts to establish the relationship between species. By using our modem understanding of these relationships, scientists can prioritize genetically unique species for conservation.

Source: http://www.nhm.ac.uk/

Why are genes so important when it comes to setting priorities for conservation? Genes are the building blocks of life. They determine the characteristics of a species and, through the process of natural selection, help species to adapt to future conditions3. By preserving genetically unique species instead of lots of genetically similar species, conservationists stand a better chance of maintaining the essential foundations of ecosystems that are ready to survive whatever the future has in store. Given the uncertainties of climate change, this adaptability will be even more important in the decades to come.

Although it would be naïve to assume that conservation can take place without taking into account the social and economic aspects of conservation, studies have shown that species with a high level of genetic uniqueness are actually more threatened than other species4, 5, 6.Whatever method of prioritization is favored, time is of the essence when it comes to conserving the genetic heritage of the species that share our planet.

References:

1. Game, E.T., P. Kareiva, and H.P. Possingham. 2013. Six Common Mistakes in Conservation Priority Setting. Conservation Biology 27: 480 – 485
2. Science Now. 2012. Bonobos Join Chimps as Closest Human Relatives. Available at: http://news.sciencemag.org/sciencenow/2012/06/bonobo-genome-sequenced.html/ [Accessed 2/7/2013]
3. Crozier, R., P-M. Agapow , and M.A. Smith. 2009. Conservation genetics: from species to habitats. Biology International 47: 73 – 79
4. Redding, D.W., and A.Ø. Mooers. 2006. Incorporating Evolutionary Measures into Conservation Prioritization. Conservation Biology 20: 1670 – 1678
5. Daru, B.H., K. Yessoufou, L.T. Mankga, and T.J. Davies. 2013. A Global Trend Towards the Loss of Evolutionarily Unique Species in Mangrove Ecosystems. PLoS ONE 8: e66686
6. Isaac, N.J., S.T. Turvey, B. Collen, C. Waterman, and J.E. Baillie. 2007. Mammals on the EDGE: Conservation Priorities Based on Threat and Phylogeny. PLoS ONE 6: e296

This post was written by:

- who has written 2 posts on dotWild.

Emma Vaughan is a wildlife science intern in the Conservation Science and Policy department of Defenders of Wildlife. Currently working towards a master’s degree in Ecosystem Science and Conservation at Duke University, Emma has a background in conservation biology, ecology, environmental science and field biology.

Contact the author

Leave a Reply

dotWild is the blog of scientists and policy experts at Defenders of Wildlife, a national, nonprofit membership organization dedicated to the protection of all native animals and plants in their natural communities.

www.defenders.org