Genetic diversity is the raw material that allows populations to evolve in response to environmental changes—the more diversity, the better.
Rapid climate warming is making it difficult for several species to evolve and adapt fast enough to avoid extinction, especially those that do not withstand much environmental variation, like those from cooler high-elevation habitats, which might also lack genetic diversity critical for climate change adaptation.
Hybridization, the process of combining different species, could assist the vulnerable in adopting and rapidly exploiting novel genetic diversity from species already adapted to warmer environments. However, hybrid populations have conventionally been thought to have little conservation value.
Natural hybridization can minimize the risk of extinction for species threatened by climate change, according to new research published in the prestigious journal Nature Climate Change.
This idea is analogous to how historical mixing between the ancestors and Neanderthals resulted in better fitness in some modern human populations.
The study group, which included lead author Dr. Chris Brauer, project coordinator Professor Luciano Beheregaray, and other biologists, took a trip to the Wet Tropics region of northeastern Australia to collect samples of five species of tropical rainbowfish along an elevational gradient.
They extracted genomic data from the samples and found numerous pure and hybrid rainbowfish populations. They also discovered genes that allow rainbowfish populations to adapt to climate variation across the region, and they used environmental models to predict how much evolution will be needed in the future for populations to keep up with climate change.
According to Dr. Brauer, populations of cool-adapted upland species that have hybridized with warm-adapted lowland species are less vulnerable to future climates.
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.
Dr. Chris Brauer, Study Lead Author, Flinders University
The discovery that hybridization (genetic mixing) may aid in rapid adaptation to climate change has significant implications for many threatened species.
According to MELFU Director and Flinders University Professor Luciano Beheregaray, this research identifies hybrid populations’ underrated conservation value.
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.
Luciano Beheregaray, Professor, Flinders University