Lion photographed by Marcus Kendall (LiC Volunteer) in the Kruger National Park
Many of us are well aware that we are currently experiencing the 6th mass extinction where the rates of species loss are higher than ever before. Conservation of biodiversity has become very important and a large part of this comes down to conserving genetic diversity, which can be roughly understood as the variation of genetic characteristics in a population. So, in the 1970s, a new branch of conservation, called conservation genetics, was born to do just that.
So how exactly is genetics used to conserve? Well, genetic diversity leads to population resilience. If all the animals in a population are identical, they could all be wiped out by a single event. However genetic diversity in a population means that some individuals will respond differently to variations in conditions, giving the population a better chance of survival in this ever-changing world.
Genetics are an important part of captive breeding programs and genetic rescue. In captive breeding programs, endangered species are bred in captivity so that their young can eventually be released into wild populations, increasing the genetic diversity of the population and therefore its resilience. Genetic rescue is when new individuals are introduced into existing populations that have been suffering from small population sizes and slow growth rates. A well-known example here is the Florida panther, where new panthers were introduced into small, isolated populations where inbreeding was a problem. The kittens produced from this introduction lived much longer and the panthers were able to exploit new habitats and expand their ranges.
Another aspect of conservation where genetics is extremely important is in the forensics of the illegal wildlife trade. DNA investigations are used to identify whether any commercial products originate from endangered or protected species. The products on the market are often processed into powders or other forms and it cannot be visually determined if they come from an animal or not. With DNA tests, it is possible to show which animal species were used and even the geographic location that the original sample is from. For example, genetic analyses showed that various shaving brushes were manufactured using Eurasian badger hair and sold in countries where this badger was protected.
The above photographs show the illegal trade of animal skins and bones at a local market in Kwa-Zulu Natal, South Africa. Photographs by Robyn De Villiers.
Over recent years, genetic technologies have become bigger, better and cheaper. This has led to some very interesting new uses of genetics for conservation. One of these is the use of cloning to save threatened species and even bring extinct species back. Genetic material from a female of an endangered species is transferred into an empty egg cell of a related but unthreatened species and then planted into the uterus of a surrogate mom. If the embryo successfully develops, the surrogate mother will eventually give birth to young of the threatened species. This sounds like a good idea, but cloning has a very low success rate and some scientists are against it because:
- It lowers the genetic variability because you are making direct copies of individuals.
- Cloning is an ‘easy fix’ solution for extinction. Why should money and effort be spent on conservation if the species can simply be brought back by cloning?
- There are several movies that show why bringing extinct species back to life might not be the best idea… Click here to see what we mean.
This gives us a lot to think about, so what would your opinion on the “to clone or not to clone” debate be?
There are many other fascinating uses for genetics in conservation, one of them being environmental DNA or eDNA. This method extracts and amplifies DNA found in soil, water, sediments and even the air. It can be used to identify individuals present in a habitat and it can estimate population sizes. It is also very handy in showing the presence of rare and elusive species and identifying invasive species that one can’t just capture and take DNA samples from. Science has made it very easy to read the DNA of any organism almost anywhere and in record time. This is done using a portable Oxford Nanopore Technologies® MinION® which can generate the genetic code of organisms directly in the field and helps with rapid species identification, making genetic analyses much easier.
But, is conservation genetics actually being used or applied where it should be? Scientists generate and interpret genetic data, but the information is more often than not passed on to the incorrect people or wildlife managers who are unable to fully understand the data. In my opinion, conservation managers should be trained in future so that they are able to draw information from genetics to make better management decisions. DNA technologies are becoming easier, cheaper and more advanced, so why should we not consider using them to conserve our loved species?
Let us know your thoughts and opinions on ‘to clone or not to clone’ in the comments!
– written by Arantxa Blecher (BSc Zoology at The University of Pretoria)