On the heels of the International Day for Biological Diversity, 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 also 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.
“Understanding the roles of evolutionary history and past climate change on terrestrial mammal diversity is important for future conservation planning,” says co-author Damien Fordham from the University of Adelaide, Australia.
“This is because genetic diversity is a building block of life, providing capacity to adapt to environmental disturbance.”
For the study, led by the University of Copenhagen, Denmark, the researchers collected and georeferenced an enormous amount of genetic data for terrestrial mammals to inform longstanding theories about its global distribution.
Despite these theories, the actual spread of genetic diversity and what drives it has thus far been a mystery, says lead author Spyros Theodoridis.
To generate the global map, 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 ran correlations between inter-, intraspecies and clade diversity and aligned them with estimates of climate stability since the Last Glacial Maximum, modelled along with human-driven change since industrialization.
Results support several converging theories, showing that multiple dimensions of genetic diversity align.
Rapid changes in temperature and rainfall have impacted this, potentially due to species extinctions, sounding a warning for future extreme weather events.
The authors note that tropical regions, home to the world’s richest genetic variation, are also facing the greatest threats from human activities such as deforestation and altered fire regimes, as well as climate change.
The Royal Institution of Australia has an education resource based on this article. You can access it here.
Natalie Parletta is a freelance science writer based in Adelaide and an adjunct senior research fellow with the University of South Australia.
Read science facts, not fiction...
There’s never been a more important time to explain the facts, cherish evidence-based knowledge and to showcase the latest scientific, technological and engineering breakthroughs. Cosmos is published by The Royal Institution of Australia, a charity dedicated to connecting people with the world of science. Financial contributions, however big or small, help us provide access to trusted science information at a time when the world needs it most. Please support us by making a donation or purchasing a subscription today.