The 'specialist' plants and animals on Earth
may struggle to adapt to climate change,
according to the research.
Image: iStockphoto

Melbourne researchers have discovered that some tropical climate species may be unable to adapt to climate change and are therefore at an increased risk of extinction.

The research was conducted by a team of scientists from the Centre for Environmental Stress and Adaptation Research (CESAR) at Monash University and the University of Melbourne and was published on 4 September in the prestigious journal Science.

Dr Carla Sgro from CESAR at Monash University said the findings suggest that specialist species have a fundamental evolutionary limit, and may be unable to adapt to future climate changes.

"It is an important piece of the evolutionary puzzle. The more varied a species' genetic make up is, the better its ability to respond to change. Adaptation is a physiological or behavioral change that makes an organism better suited to its environment. Since adaptations usually occur due to a change (or mutation) in a gene, species with a more varied set of genes are likely to have a greater ability to adapt, Dr Sgro said.

"The concern is that habitat specialists make up most of our earth's biodiversity, suggesting that this inability to adapt will affect many species, including groups of insects and potentially other groups such as mammals and fish as well.

"This work is important because understanding the link between genetic diversity and species distributions will provide a way of assessing and predicting the ability of species to adapt to climate change. This may assist in conservation efforts by identifying species vulnerable to future climate changes," Dr Sgro said.

Vanessa Kellermann and Belinda van Heerwaarden did the laboratory research under the supervision of University of Melbourne's Professor Ary Hoffmann and Dr Sgro. They used vinegar flies (Drosophila) as a model, examining species that lived in tropical and more widely distributed environments. Their research revealed that the flies restricted to tropical environments have a narrower set of genes for traits such as tolerance to drying (desiccation) and cold resistance, in effect preventing adaptation.

"It has previously been thought that all species contain enough variation in their genes to enable adaptation to changing environmental conditions, however this may not actually be true for specialist species. Our new findings indicate that a species' range is closely linked to the amount of genetic variation in important traits such as stress resistance," Dr Sgro said.

"In effect, we now have a genetic explanation for why species are restricted -- they just don't have the genes needed to adapt to different environments."

Dr Carla M. Sgro is an ARC Australian Research Fellow with Monash University's School of Biological Sciences.