Animals in human altered areas have higher risk of extinction – University of Copenhagen

29 September 2016

Animals in human altered areas have higher risk of extinction

Genetic diversity

Human activity has already transformed the surface of the Earth. Now it also seems to reduce genetic diversity within animals - putting them at higher risk of extinction. The discovery was made by scientists from Centre for Macroecology, Evolution and Climate at the University of Copenhagen, and published today in Science.

Mammals and amphibians living in areas heavily altered by humans have less prospects of adapting to changes in their environment. A new study published today in Science shows lower genetic diversity in animals from regions with high human impact compared to animals in less impacted areas. First-author and postdoctoral researcher Andreia Miraldo, from the Centre for Macroecology, Evolution and Climate at the University of Copenhagen, explains

The map shows the destribution of genetic diversity on Earth. The genetic diversity is concentrated in the tropics and in areas not altered by humans. Press photo.

- Having genetic variation within a population means that whilst some individuals die from changed conditions in their living environment, like an increase in temperature, others are able to survive because they are different at the genetic level and therefore possess different traits. In this sense, genetic diversity within species determines their ability to survive the increasing human impacts on the environment like climate change.

Tropical regions are arks of biodiversity

Tropical regions not only contain the highest number of species on Earth, they also turn out to hold the highest amount of genetic diversity, the new study shows. While the tropics constitute hotspots of genetic diversity, the study shows that it decreases when moving towards the Polar Regions. Senior author and Associate Professor David Nogués-Bravo, elaborates,

Tropical regions are the areas with the highest genetic diversity on Earth. Press photo (Photo: Andreia Miraldo).

- Our results make it clear that the tropics really are the richest regions in terms of biodiversity at all levels, ranging from tiny genes to major ecosystems. On the contrary, we found very low levels of genetic diversity for amphibians in Western Europe. This suggests that the region's long history of human presence and heavy alteration of nature, has taken its toll on genetic diversity. This leaves species in Europe and other areas altered by humans extra vulnerable to environmental change because low genetic diversity entails a higher risk of becoming extinct.

First global map of genetic diversity

To conduct the study the scientists pulled together more than ninety thousands genetic sequences from amphibians and terrestrial mammals that were available online. By attaching geographic coordinates to each sequence they were able to calculate genetic diversity in hundreds of localities throughout the world, allowing the team to map, for the first time, the distribution of genetic diversity on Earth.

-We are now in a much stronger position to test which potential mechanisms have led to this spectacular biological diversity in the tropics, and we are thus one step closer to unravelling the really big question of what determines the global distribution of biodiversity, Andreia Miraldo concludes.

Read the paper

Use the map


Postdoctoral researcher Andreia Miraldo
Mobile: (+45) 50 23 99 43
(Language for interviews: English and Portuguese)

Associate Professor David Nogués-Bravo
Mobile: (+45) 27 47 93 99 (Only via WhatsApp)
(Languages for interviews: English and Spanish)