Major bird study could help us fight the next pandemic

EVOLUTION New study uncovers the intricate factors that drive the evolution of genomes. Utilizing data from the world’s largest bird genome database, it could have implications such as understanding how diseases adapt to human demographics or climate conditions
Birds in flight
The diversity of birds could be used to investigate the genetic changes driving everything from pandemics to species adaptation in shifting ecosystems (photo: Unsplash.com).

Evolution. Nature’s engine, driving and shaping genetic change and the diversity around us. Charles Darwin famously unveiled this process through his theory of natural selection, revealing how species adapt and evolve over time.

At its core, evolution is based on changes to DNA, which lead to the striking diversity of life forms that we see today. This includes the appearance of baffling characteristics in animals and the concerning new pathogens that we saw in the recent pandemic.

Understanding these changes is crucial not only to biodiversity conservation but also to understand and address the alarming novelty in pathogenic mutation.

Now, a study lead by the University of Copenhagen has made a significant leap forward in understanding what drives evolution.

“Basically, we showcase a method to a method to extract information from genomes and reveal the forces driving biological novelty with unprecedented detail," says Associate Professor David Duchene from the Department of Public Health at the University of Copenhagen.

Our findings can be applied to a variety of contexts, such as understanding how diseases adapt to human demographics or climate conditions.
David Duchene, Associate Professor at the Department of Public Health

"We used birds as our study subject. With 10,000 known species, they are the most diverse class of vertebrates and uniquely suited for exploring evolutionary phenomena. With our method, we were able to identify key factors that influence how these bird lineages and their thousands of genes evolve,” explains David Duchene.

The four main factors drive genetic novelty

  1. Clutch size: Larger numbers of chicks lead to faster genetic change, as more events of genome replication increase opportunities for the copy-mistakes we call ‘mutations’.
  2. Chemical composition of genes: Certain molecules, like cytosine and guanine, appear to accelerate gene evolution—a factor likely applicable across many organisms.
  3. Small chromosomes: Birds’ tiny chromosomes evolve quickly and are highly variable, contributing significantly to their genetic diversity.
  4. Gene regulation and leg length: Changes in gene regulation is strongly linked with the ecological variable of leg length—a proxy for flight versus terrestrial behavior, that is, how much time is spent on the ground versus in the air, along other major lifestyle differences.

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The four key factors were clutch size, biochemical composition of genes, chromosome size and leg length as measured using the tarsus bone. David Duchene explains that the new results challenge the notion that a single major factor drives evolution in a group (e.g., flight habits, sociality, or song in birds).

“Our study tells us that you will find much nuance as to the drivers of novelty once you look at multiple lineages and genes in detail. The biochemistry, chromosomes, and various aspects of lifestyle all play distinct roles in bringing about novelty,” he says.

Can help us understand the next pandemic

While birds were also Darwin’s study subject, the new findings go beyond vertebrates and offer a roadmap for studying evolutionary processes in diverse organisms, including mammals, plants, and even pathogens.

“Our findings can be applied to a variety of contexts, such as understanding how diseases adapt to human demographics or climate conditions. The same principles that help us decode the diversity of birds could also be used to investigate the genetic changes driving everything from pandemics to species adaptation in shifting ecosystems,” says David Duchene.

“This method could tell us: What is special about what we are losing in the current biodiversity crisis? What exactly made those animals so novel and unique, and what have they taught us about evolution such that we might want to preserve them?”

The study is the result of an extensive international collaboration involving researchers from multiple disciplines and institutions.

From the University of Copenhagen, the Department of Public Health, Globe Institute, and Department of Biology worked closely together. Internationally, the project includes contributions from Imperial College London, the University of Sydney in Australia, and multiple research teams in China.

Read the full study “Drivers of avian genomic change revealed by evolutionary rate decomposition”.

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