Abby Tabor
The United Nations Decade on Biodiversity has begun. The mission has been defined and targets established. The task is huge, however, and will require creative solutions from every possible angle. Genetics will play its role by revealing how species work on the most fundamental level, allowing scientists to choose the best strategies for their protection, make them stronger, more resilient, and better able to defend themselves.
In 2010, the United Nations observed an entire year of biodiversity awareness. But 365 days wasn’t nearly enough. At the initiative of Japan, 2011-2020 has been declared the United Nations Decade on Biodiversity and was officially launched in December. The UN recognizes the importance of biodiversity, not only for “food security, human health, and economic development, but also as a central component of many belief systems, worldviews and identities.” Humanity simply cannot be separated from its environment. Knowing this, the UN has established a Strategic Plan for Biodiversity, with the goal of halting and even reversing the rate of species loss. The plan defines specific goals and sets forth concrete targets for local communities. Meeting them will require serious commitment and ingenuity on the part of citizens, lawmakers, and scientists. One approach will take biodiversity to the lab bench, for many solutions toward protecting species may be found in their genetic makeup.
Genetics has come a long way in the last 20 years in asserting its potential as a tool for conservationists. In the mid 1990s Richard Frankham, senior author of Introduction to Conservation Genetics, the first textbook in the field, observed that the effect of genetics on endangerment and extinction of species was highly underrated: it was thought to be important only for very small populations and the “impact of loss of genetic variation in increasing the susceptibility of populations to environmental [fluctuations] and catastrophes has generally been ignored.” Today, in contrast, many universities offer programs devoted entirely to the study of conservation genetics.
Along with better understanding of the complex interactions of genes, environment, and population dynamics, improvements in DNA analysis technologies have helped establish genetics in the conservation world. Tests that once would have been far too laborious, costly and time consuming have now become quite routine. From northern Italy to northern Montana, bears have been studied on the genetic level to learn more about their populations and find relevant strategies to protect them. Last year, genetic markers were found for identifying a species of reef-building coral in the Mediterranean, which will aid in developing conservation plans. Meanwhile, off the Pacific coast of Colombia, genetic analyses of sharks found stranded, or confiscated from poachers, permitted the identification of the species most at risk. Genetics is now so at home in conservation biology that the authors of the latter study feel their technique “is an easy-to-implement and reliable identification method that could even be used locally to monitor shark captures in the main fishing ports of developed and developing countries.”
By complementing information from other areas of biology, genetics can help wildlife managers respond to risks imposed on species by, say, climate change or loss of habitat. This may be especially true when the danger is over-exploitation of a species useful to human populations. This is the case for devil’s claw, a plant found in southern Africa and appreciated around the world for its medicinal properties. The plant is a tuber, like a potato, which can be boiled to give a drinkable infusion or made into ointments. Standardized preparations, like Doloteffin, are available on the global market. Although scientific studies have reported only that Devil’s Claw is “possibly effective” for treating lower back pain, arthritis-associated pain, and for stimulating digestion, the plant remains a sought-after treatment and an important source of income for many communities.
A problem compounded by reduced availability of habitat due to agricultural expansion, the tuber is a victim of its own success: devil’s claw suffers from over harvesting – a problem with very human origins. In this case, genetics in the service of conservation can also have an immediate interest for the community, in the form of a boost to the local economy.
Gladys Kahaka is a biotechnologist at the University of Namibia. Knowing the importance of devil’s claw to communities in her country, she has decided to put her research to work for the plant’s conservation. Selected for a 2012 L’Oréal-UNESCO For Women in Science international fellowship, Dr. Kahaka will use the award to develop her DNA analysis skills at the University of Nottingham in the UK. Specifically, what she wants to be able to do is find out which devil’s claw genes are most important to the plant’s development. “If you can identify the genes that help it grow, you can create jobs, harvest it sustainably, and produce enough to export.”
There is, of course, a bit of work to do between the identification of important genes and a successful harvest. The technique of transcriptomics looks at all the RNA that has been produced from an organism’s DNA—that is, the products of its genes—and compares it to the genes of another, well known organism. In this case, the standard for comparison is the heavily studied plant, Arabidopsis. Wherever the two plants’ genomes share the same pattern, a match is made, providing a clue to the function of the devil’s claw gene: maybe it’s involved in the ability to germinate, or perhaps in drought resistance. Researchers then take this preliminary information and refer to a database, called BLAST, that makes more comparisons with other species, giving more evidence for the roles of different genes.
“Once you find important genes, you start playing around with them, and see what phenotypes you get. Will the mutant grow, or does your mutation prevent germination, for instance? It’s also vital to make sure your manipulation doesn’t affect the desired medicinal properties.” Those properties, after all, are the reason for so much interest in Devil’s claw, and an important source of livelihood for many Namibian communities.
Gladys Kahaka plans to carry out similar experiments with the fruit-bearing Ximenia plant. Here, it is a question of nutrition. Ximenia is slow-growing, as well as seasonal, so its production is inherently limited. “But, if you can get it to grow at any time, you can produce more fruit and other products. Then, once it’s commercialized, it will be on the market, even in regions that don’t have Ximenia plants.”
The utility of genetics need not stop there. Recognizing that the main tourist attraction in Namibia is its wildlife, Dr. Kahaka is also thinking of applying these methods of gene identification to the cheetah. The fastest land animal on Earth is now dangerously inbred, due to its small population size, making it susceptible to disease and environmental change. By revealing the genetic makeup of this cat, she hopes that other scientists will use the information to examine the diseases affecting cheetahs and provide them with better care. Referring to the reserve where cats are brought for their safety after coming into conflict with farmers, she explains that “animals get sick just like us. When we bring them to the park, they are taken out of their natural system of protection, so we need to be able to treat them.”
Maintaining biodiversity will indeed serve an array of immediate human interests, but rarely is it that simple. Gladys Kahaka will work on three species that are useful to her country, knowing full well that all the world’s food, medicine, economy and natural beauty depend on healthy ecosystems. And for that, the importance of biodiversity cannot be overestimated.
