The 1995 Nobel Prize winner for Chemistry, Paul Crutzen, revitalized in 2000 the use of the name Anthropocene to refer to the geological era or epoch (in which we live today) characterized by the impact of human activities. The scientific debate on this classification is still open, but evidence is accumulating that the action of our species is marking -in many aspects, in a negative way- life on the planet as a whole.
A study published this week in the journal Science by a team of researchers headed by Moisés Exposito-Alonso, from the Carnegie Institution for Science and Stanford University (United States), provides new data in this regard; to the point of calculating that phenomena associated with the Anthropocene such as climate change and the destruction of natural habitats (spaces where wild flora and fauna live) have caused the loss of more than 10% of the genetic diversity on our planet. The title of the scientific article leaves little room for doubt: “Loss of genetic diversity in the Anthropocene”. It is not only about the loss of species but also about the loss of genetic variations within each species, due in part to the decrease in the number of individuals.
The calculations presented in this study are so worrying that the Carneige Institution itself recalls that they could mean that “it is already too late to meet the goal proposed by the United Nations, announced last year, of protecting 90% of genetic diversity of all species by 2030, and that we need to act quickly to prevent further losses.
Several hundred species of animals and plants have become extinct in the industrial age, and human activity has impacted or reduced half of the Earth’s ecosystems, affecting millions of species, the authors of the new study summarize.
Partial loss of geographic range decreases population size and may geographically prevent populations of the same species from interacting with each other. This has serious implications for the genetic richness of an animal or plant and its ability to meet the upcoming challenges of climate change, details the briefing note from the Carneige Institution.
“When you remove or fundamentally alter swathes of a species’ habitat, you restrict the genetic wealth available to help those plants and animals adapt to changing conditions,” explained Exposito-Alonso, Staff Associate from the Carnegie Institution and an associate professor at Stanford University.
Until recently, this important component has been overlooked when setting goals to preserve biodiversity, but without a diverse set of natural genetic mutations to draw on, species will have limited ability to survive disturbances in their range. geographic.
The authors recall that genetic mutations are small, random natural variations in the genetic code that could positively or negatively affect an individual organism’s ability to survive and reproduce, passing on positive traits to future generations.
“As a result, the larger the pool of mutations a species can turn to, the greater the chance of stumbling upon that lucky combination that will help a species thrive despite pressures created by habitat loss, as well as changes in temperature and precipitation patterns,” added Expósito-Alonso.
The authors of the new study set out to develop a population genetics-based framework for assessing the richness of mutations available to a species within a given area.
They analyzed genomic data from more than 10,000 individual organisms from 20 different species to show that Earth’s terrestrial plant and animal life may already be at much greater risk from loss of genetic diversity than previously thought. Because the rate at which genetic diversity is regained is much slower than the rate at which it is lost, researchers consider it to be effectively irreversible.
“The mathematical tool we tested on 20 species could be expanded to make approximate conservation genetic projections for additional species, even if we don’t know their genomes,” Exposito-Alonso concluded. “I think our findings could be used to assess and track new global sustainability targets, but there is still a lot of uncertainty. We need to do a better job tracking species populations and developing more genetic tools.”
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The Anthropocene has already caused the destruction of more than 10% of the planet’s genetic diversity