Hybridization reduces vulnerability to climate change

Rapid climate change is forcing many species to evolve and adapt quickly enough to avoid extinction, particularly those that do not tolerate a large degree of environmental variation, such as species from cooler high-elevation habitats, which often lack the genetic diversity that is crucial for adapting to global warming.

According to a new study led by Flinders University in Australia, hybridization – the process of mixing different species – could potentially help the most vulnerable ones adapt and rapidly exploit novel genetic diversity from species that are already adapted to warmer environments. This concept is similar to how the historic mixing between our ancestors and Neanderthals seems to have improved the fitness of some modern human populations.

To test this hypothesis, the scientists traveled to the Wet Tropics region of northeastern Australia to collect samples of five species of tropical rainbowfish along an elevation gradient. Genetic analysis of the samples revealed both pure and hybrid populations of rainbowfish, and helped the researchers identify genes that enable rainbowfish populations to adapt to climate variation.

More specifically, the populations of cool-adapted upland species that have hybridized with a warm-adapted lowland species showed reduced vulnerability to future warming scenarios. “These mixed populations contain more diversity at genes we think are important for climate adaptation, and are therefore more likely to persist in warmer environments,” explained study lead author Chris Brauer, a research fellow in Landscape Genomics at Flinders University. 

These findings highlight the underappreciated conservation value of hybrid populations, suggesting that hybridization may facilitate rapid adaptation to climate change. “Our findings are good news for biodiversity. They indicate that genetic mixing is an important tool for conservation that can contribute to natural evolutionary rescue of species threatened by climate change,” concluded senior author Luciano Beheregaray, a professor of Biodiversity Genomics at Flinders.

The study published in the journal Nature Climate Change.

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By Andrei Ionescu, Earth.com Staff Writer

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