Genetic Diversity Of Lions Decreasing
Posted on July 14th 2019
Explorers and settlers have been warning for more than a hundred years about the negative impact of hunting lions and other wild animals in Africa. Now the latest research bears out these fears and has revealed the true impact of predation on lions. Lion numbers in the range studied have plunged and it would seem that their genetic fitness has also experienced a decline. The study reveals that lions killed by hunters over a century ago were more genetically diverse than today’s African lions.
This discovery is particularly troubling because it suggests that the species will find it even more difficult to survive than what was previously believed. Experts say the loss of genetic diversity means that lions are now less able to defend themselves from new disease or problems with the environment such as droughts or heatwaves. It also means we must be more careful about how we protect the species.
Huge fall in numbers
Towards the end of the 19th century there were close to 200,000 lions roaming the African savannahs. The first colonialists from Europe arrived and immediately began hunting them. Lions are the most social cat species. They were shot and killed in their thousands initially for sport and later to protect livestock that the settlers had started to farm. Now there are less than 20,000 lions left in Africa and the species is classified as vulnerable.
Experts say they are aware that the number of lions has dropped however they say they were caught completely by surprise when they learned just how badly the survivors had fared genetically. The researchers looked at two sources of lion DNA. The first source of DNA was taken from wild lions in a reserve that spans Botswana, Namibia, Zimbabwe and Zambia and has the same area as the UK. The Kavango-Zambezi conservation is one of the largest Areas left in Africa where lions are able to roam relatively undisturbed.
Findings were striking
The second DNA source was taken from skin and bone samples of specimens that are housed at the Natural History Museum. These lions were shot by hunters and explorers between 1879 and 1935 and their remains sent to the museum. DNA was extracted from both sets by researchers from several countries in Africa and the UK and then compared. What they found they say was striking.
The genetic diversity of modern-day lions has fallen by 15 per cent and that has important implications. Any species that has high genetic diversity has a wider selection of different versions of genes compared to a species of low genetic diversity. This makes the high genetically diversified species better able to cope with environmental change, disease and other threats. The latest research suggests that over the last century lions have lost some of that ability due to hunting and habitat destruction.
Experts say this is an important discovery because climate change is likely to result in new diseases among African wildlife and it is highly likely that drought and heatwaves occur more frequently. As genetic diversity declines, lions will continue to face further threats. Additionally, as farmers continue to parcel out an increasing amount of land, it will become harder for lions to move and interact and further reduce genetic diversity.