Longevity Briefs: Measuring Biodiversity from DNA in the Air

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Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

Why is this research important: The variety of animal and plant life in the natural world is not only essential for maintaining natural processes that support all life on Earth, but it is also what makes this planet such an incredible place.

Humanity has had a considerable impact on this biodiversity. Unfortunately, this has largely been negative. One of the most significant impacts has been the loss of habitat, due to farming and gathering of natural resources, which has resulted in the extinction of many species. Other impacts include the introduction of non-native species, the spread of disease, and the pollution of ecosystems.

Despite its importance, biodiversity is often difficult to quantify and study. As highlighted by the United Nations Sustainable Development Goals, measuring biodiversity is a fundamental challenge in realising the scale of the human impact on ecosystems, and being able to effectively mitigate it.

United Nations Sustainable Development Goals (SDGs). Source: United Nations

For aquatic ecosystems there has been an explosion of interest in the use of environmental DNA, or eDNA, to assess populations and track invasive species. eDNA is DNA that has been isolated from environmental samples, such as water, soil, and air. eDNA sequencing can be used to detect the presence of certain species in an environment, and can be used to monitor the environment for changes in biodiversity. Together with the growth of vast DNA reference databases, this has transformed our ability to monitor aquatic ecosystems.

Despite this model, similar methods have not been widely adopted in terrestrial ecosystems.

What did the researchers do: In a recent publication in CellPress, researchers set out with the goal of collecting eDNA in air samples, to test the hypothesis that eDNA from terrestrial animals is carried in the air.

The team collected 72 air samples, from 20 different locations within Hamerton Zoo, in the UK. They then extracted the eDNA from the samples and sequenced the isolated DNA on an Illumina Miseq system.

Aerial shot of Hamerton Zoo, UK. Source: The Sabbatical Guide

Key takeaway(s) from this research: The researchers found that the air samples they had collected contained DNA from 25 different species of animals, including 17 known terrestrial resident zoo species. This proved their original hypothesis, confirming that sampling airborne eDNA is an accurate method of quantifying the biodiversity of a known system.

Not only this, incredibly, the detection of livestock animal eDNA (chicken, cows, pig) allowed the scientists to correctly identify exactly what the carnivores in the zoo had been eating that day.

The novel opportunities that eDNA approaches provide for the non-invasive monitoring of species of special concern, and the detection of the human impact on ecosystems and wildlife populations, are extremely exciting and suggest that airborne eDNA could revolutionise the ways in which scientists study and monitor terrestrial biodiversity non-invasively on a global scale.