Ecometrics Approach Shows the Evolution of Mammalian Traits With Changing Environments, Sheds Light on Future Biodiversity Losses

For millions of years, mammalian megafauna have played a significant role in the functions of the Earth's biosphere as they serve as prey, create habitats, help plants thrive, and even influence wildfires. Compared to the number of mammalian species that were alive 50,000 years ago, fewer than half of their population in the past exist today. Those that survived face the threat of extinction from intense climate change and human activities.

Documenting Mammalian Extinctions

At Georgia Institute of Technology, researchers used a novel approach in investigating how the ability of mammals to function in their environments has been threatened in the past. They also analyzed the challenges that these animals may face in the future.

Jenny McGuire and Daniel Lauer from the School of Biological Sciences observed the relationships of eastern African herbivores with their environments and how they changed across time and space amidst the biodiversity crisis. They used novel technology to build models that show specific animal traits' evolution with their changing environments.

Their investigation started by collecting data from 186 sites across eastern Africa, showing records of 200 extinct and 48 modern herbivore species. By analyzing where and when each species lived at a given point in time over the past 7.4 million years, it was found that mammal biodiversity in this region began to decline around 5 million years ago. It was also discovered that factors of biodiversity decline occurred at multiple points, with extinctions coinciding with environmental changes and the emergence of early humans.

McGuire and Lauer wanted to know more, as they wondered how the physical traits of mammals changed as their environments changed over time. They needed to study biodiversity from a different perspective to answer their question. This required them to use an approach that adapts a method known as ecometrics.

From their ecometric framework, the scientists unveiled a significant difference between the mammal biodiversity declines that occurred 1.7 million years ago and those that happened after. Although biodiversity decline began 5 million years ago, the relationships between traits and environments remained consistent despite that loss.

The result of the study provides new insight into prioritizing mammal communities for future conservation efforts. The findings indicate that priority should be given to those most at risk among all the communities that suffer from biodiversity losses.

What is the Ecometric Approach?

Ecometrics refers to a technique that looks at the relationships between the environmental conditions and the functional traits of animals that affect their biological performance. The key to the ecometric approach is the identification of specific trait-environment connections and using these traits in studying the pairing dynamics across space and time.

Ecometrics can quantify the interactions of organisms with their environment by focusing on the measurable traits whose structure is closely related to their function and whose biological function interacts directly with their immediate environment. This makes ecometric trait distributions a comparatively universal metric in investigating systems dynamics at all scales.