Jacinta Bowler
Jacinta Bowler is a science journalist at Cosmos.
They were published in the Best Australian Science Writing 2023.
Hybrids are normally given a bad rap. Thinking of sterile mules or ligers, it’s pretty hard to see how they could be useful for conservation.
However, a new research paper has looked at natural hybridisation in rainbowfish, finding it can reduce the risk of extinction of species threatened by climate change and therefore they deserve more consideration around species preservation.
“Our findings are good news for biodiversity,” said Flinders University biodiversity geneticist Professor Luciano Beheregaray.
“They indicate that genetic mixing is an important tool for conservation that can contribute to natural evolutionary rescue of species threatened by climate change.”
The researchers looked at five species of rainbowfish in the wet tropics of inland north Queensland – all from the Melanotaenia genus – and analysed their genes that would allow them to adapt to climate changes. They also analysed their habitat and environmental models to determine how much evolution would be required for the rainbowfish to keep pace with climate change.
The researchers also looked at certain sections where two species meet, and where hybrids of the species have been found.
“The role of hybrid populations in conservation is controversial due to concerns about diluting the genetic integrity of parental species, as well as policy and legislative uncertainty,” the researchers wrote in their new paper.
“The threat posed by these issues, however, is likely to be case-specific and may be less of a concern if hybridisation is natural and has occurred over an extended period.”
This is exactly what the researchers found. They discovered that populations of cool-adapted upland species that have hybridised with a warm-adapted lowland species had a reduced vulnerability to future warmer 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,” said Flinders University conservation scientist Dr Chris Brauer.
Although this is just one species of fish, other research has also found that natural hybridisation occurs in many animals, including mammals, birds, fish, fungi, and insects.
“Hybrid zones could potentially facilitate evolutionary rescue of many species threatened by climate change,” the researchers wrote in their new paper.
“This has led to a call for hybrid populations to be given greater conservation value in policy and management decisions.”
The research has been published in Nature Climate Change.