Last updated May 27, 2020 at 12:05 pm
Scientists have compiled a global map of genetic diversity in mammals and it highlights key biodiversity hotspots for conservation efforts.
Why This Matters: Now we need to turn plans into action.
On the back of the International Day for Biological Diversity, Australian and Danish scientists have compiled the first comprehensive map of genetic diversity for terrestrial mammals across the planet.
They found that tropical regions with rich evolutionary histories, such as Amazonia, Northern Andes, central American jungles, sub-Saharan Africa and south-eastern Asia, are treasure troves of genetic diversity within species.
Further analysis revealed that stable climates over the past 21,000 years likely made an important contribution to their genetic richness.
Intra-species genetic diversity not only makes animals unique, it is critical for adaptation and survival.
Genetic diversity provides a capacity to adapt
“Genetic diversity within species is a critical component of biodiversity, playing two important roles at the same time. It reflects species evolutionary history and defines their capacity to adapt under future environmental change,” says Spyros Theodoridis, who led the study at the University of Copenhagen. The Danish team collaborated with researchers from the University of Adelaide for the study.
However, the patterns of genetic diversity across the globe, and the factors that drive increased genetic diversity, still had question marks.
For the study, the researchers collected and mapped an enormous amount of genetic data for terrestrial mammals to produce a clearer picture of the scale and global distribution of varying levels of genetic diversity.
Areas with most genetic diversity also at risk from human activities
The team drew from public databases containing nearly 47,000 mammalian genetic sequences from more than 1500 species and their locations, which they mapped along with their evolutionary relationships.
They found that, in general, areas which had a relatively stable climate with little variability from year to year, had higher levels of genetic diversity. In particular, they write that tropical regions with a history of relatively stable climate and rainfall patterns, such as the Amazon, have had less changes in the types of species living there, leading to higher levels genetic diversity.
The research also found that accelerated climate change since the Last Glacial Maximum has resulted in lower levels of genetic diversity in temperate and polar regions. These rapid changes, which can be seen in the long term temperature and rainfall trends say the researchers, have led to reduced species populations and lower levels of genetic diversity.
The authors write that the results show the need to conserve tropical regions in particular, which were found to have the highest levels of genetic diversity and evolutionary potential.
In particular, these areas are facing the greatest threats from human activities such as deforestation and altered fire regimes, as well as climate change.
“While we show that areas of high genetic diversity tend to occur in regions where climates have remained relatively unchanged during past periods of global-scale climate change, many of these regions are forecast to experience major climate disturbances in the near future. Unfortunately, this is likely to lead to a loss of genetic diversity in many biodiversity hotspots”, says Damien Fordham, who worked on the research at the University of Adelaide.
The authors conclude: “As global change continues to transform Earth’s biota, conserving areas of particular importance for primary dimensions of biodiversity, including genetic variation in wild populations, will help meet the targets… for halting accelerating rates of biodiversity loss.”