Credit: Photo by Philip Barrington from Pixabay.
Scientists at the University of Adelaide have challenged the popular assumption that the genetic diversity of a species is a major indicator of the risk of extinction.
Published in the journal PNAS, Scientists have shown that there is no simple relationship between genetic diversity and species survival. However, Dr João Teixeira and Dr Christian Huber of the University of Adelaide School of Biological Sciences concluded that the focus should not be on genetic diversity anyway, but rather on protecting habitats.
“Humans are destroying nature at an unprecedented rate,” says computational biologist Dr. Huber. “We are burning forests, overfishing our seas, destroying wilderness areas, and it is estimated that about a million species are threatened with extinction, some within decades.
“Although researchers agree that this rapid decline in species numbers should stop, the best way to deal with it is still open to debate.
Conservation geneticists consider genetic diversity an important way to assess whether a species is threatened with extinction. The view is that as long as individuals are genetically different from each other (they have high genetic diversity), there will always be individuals with the correct genetic makeup to survive under adverse conditions. On the other hand, if a species exhibits little genetic diversity, the species is thought to be fragile and likely to become extinct. “
Dr. Teixeira and Dr. Huber have collected a wide range of evidence from laboratory experiments, field studies, and evolutionary theory that points to the need to re-evaluate the measurement and interpretation of genetic diversity for conservation.
“In this paper, we showed that this simple relationship between genetic diversity and survival is often wrong,” says population geneticist Dr. Teixeira. “Most of the genetic diversity within a genome is ‘neutral’, which means that it does not improve or reduce an individual’s ability to survive or produce offspring. On the other hand, the genetic diversity that affects survival is present in very specific areas of the genome and is not at all related to genetic diversity. At the genome level.
“Researchers need to look for each species separately, which genetic mutations allow the species to flourish and which mutations lead to diseases that could threaten the species. There is certainly no simple” one size fits all “measure of extinction risk.
The authors finally caution that although genes can play an important role in certain situations, focusing on genetic diversity shifts the much-needed focus away from the bigger problem: habitat destruction.
“Since 2000, the wildlife habitat has been lost about eight times the size of the United Kingdom,” says Dr. Huber. “Without a habitat, there is no wildlife. Without the wildlife and ecosystem services that humans depend on, we ultimately risk our security and our survival here on Earth.”
Dr. Christian Huber, School of Biological Sciences, University