The aim of biodiversity conservation is the preservation of all plant and animal species, and their habitats and ecosystems.
DNA can be exploited in several ways to promote and conserve biodiversity: to monitor the state, geographical spread, and genetic diversity of endangered species; in investigative forensic activity to source endangered animal products and implicate the guilt of poachers and traders, and as a safety net against eventual extinction by the preservation of the genome of species.
Environmental DNA (eDNA) is obtained from environmental samples and can be utilized to monitor biodiversity and investigate ancient ecosystems. DNA is continuously shed into the environment by living creatures, in the form of skin cells, urine, feces, and hair, in addition to the remains left following death.
DNA can persist for a widely varying length of time in the environment, from weeks in temperate water to many thousands of years in dry frozen climates. PCR amplification and next-generation sequencing are utilized to sequence such DNA, searching for specific primers that can be multi-species if the DNA is unknown, or use a genetic primer for a particular group of organisms if the source is known.
A diverse range of plants and animals have been recognized through eDNA collected from cave sediments and permafrost containing DNA from tens or hundreds of thousands of years ago, and from aquatic sediments and freshwater reflecting the DNA of animals living in the present day.
eDNA allows researchers to track how changes in the environment affect species diversity, and to better understand how conservation efforts could be directed to better protect extant species. Currently, the recording of species number and biodistribution may encompass various invasive methods that demand the collection of DNA samples from living animals, while eDNA may present a non-invasive method of sequencing the genome of animals of concern.
Biodiversity. Image Credit: Chinnapong/Shutterstock.com
Forensic DNA analysis
Forensic DNA analysis of endangered animals, plants, and products derived from them, is increasingly being employed in the fight against poaching and the black market animal trade. Cooked meat, hair, and skin collected from local markets is sequenced to prosecute poachers, and other products such as traditional East Asian medicines have been demonstrated to illegally contain products derived from endangered animals by DNA sequencing.
DNA sequencing has also played a forensic role in placing poachers and traders at the scene of the crime through blood sample evidence, and by demonstration of having acquired a mite infection in the country of goods origin. Similarly, the predators of endangered animals have been identified by DNA sequencing of the saliva left on the carcass.
The specific location of endangered animals and plants that are being illegally farmed can also be inferred by DNA sequencing, with local environmental conditions and nutrient availability influencing the genetic profile observed.
DNA tracking and storage
Animal species that are now very few in number in the wild, such as tigers, can potentially be entirely sequenced, with DNA testing being used to differentiate and track individuals across the whole species. This could allow conservationists to better identify sub-species, and aid the population by promoting genetic diversity and correcting for inbreeding, if necessary.
DNA databanks are under construction. These aim to preserve the DNA sequences of as many species as possible. They take the form of living conservation sites, seed and tissue/cell sample banks, and computer-based sequence storage. In the future, should DNA sequencing become as advanced as it seems likely to become, it will be possible to produce any organism from digitally stored or constructed DNA sequences.