Posted on behalf of Lee Sweetlove
A recent paper in Nature Climate Change suggests that global warming will cause substantial loss of genetic diversity amongst species (see ‘Climate change will hit genetic diversity’). This is generally considered to be a bad thing – genetic variation is the heartbeat of evolution and without it species are less able to adapt to new conditions.
However, new research on the Iberian lynx (pictured) shows that low genetic diversity does not necessarily doom a species to extinction. The Iberian Lynx has had extremely low levels of genetic variation over the last 50,000 years but this doesn’t appear to have affected its long term survival – until recently.
The work, published in Molecular Ecology, analysed a normally highly variable region of mitochondrial DNA extracted from remains of Iberian lynx teeth and bones spanning a time range from the Late Pleistocene to the twentieth century. “We knew that the current very small population of Iberian Lynxes has low genetic diversity,” says author Love Dalén of the Swedish Museum of Natural History. “But we assumed this was the result of the recent crash in the population over the last fifty years or so.” It was a “big surprise” to find that the Iberian lynx population has lacked genetic diversity throughout its history.
Dalén thinks that this persistent lack of genetic variation is the result of a stable but small population of as few as a couple thousand individuals. He is not sure if other species could survive for such a long time with such a low level of genetic diversity. “The Iberian Lynx could be a special case,” he says. “It may be that the population is pre-adapted to avoid the problems of inbreeding by containing few of the bad gene variants that tend to accumulate in inbred populations.”
This work does not therefore mean we should stop worrying about a decline in genetic variation in populations of animals and plants. But Dalén has a clear message: “Just because a species has low genetic diversity that doesn’t necessarily mean it is on the verge of extinction. From a conservation standpoint this is not a reason for giving up on a species.”
Image via Wikimedia Commons.