The long-term impact of climate change on natural communities of wild animals could be better understood thanks to a new study which sheds light on how species and their natural enemies chase each other across continents in a game of cat and mouse lasting for millions of years.A parasitoid attacking a host in a gall

The research published this week in the journal Current Biology will help to predict how migration of animals or changes to their habitats associated with climate change could impact on the evolution of relationships between predators and their prey.

Scientists used a technique known as population genetics to reconstruct the assembly history of a geographically widespread insect community, revealing historical information hidden in the DNA of small plant-feeding insects and their wasp enemies, and to show how closely predators track their prey over long periods of time.

The study looked at 31 species, 12 plant-feeding gall wasps and 19 parasitoid natural enemies, all of which originated in Iran and Turkey and spread into Europe over the past four million years. The timing of each species' journey was determined by how well it coped with the many ice ages during this period of Earth's history.

Researchers found that during these natural cycles of climate change, the plant-feeding insects often outran their predators, moving faster and so escaping attack – often for hundreds of thousands of years. Battles between predators and prey were sometimes interrupted for long periods of time, suspending the race between the two groups.

The new study was led by scientists from the University of Edinburgh in collaboration with Dr Karsten Schönrogge of the UK Centre for Ecology (CEH) and researchers from Hungary, Spain, France and the United States. The project was supported by the Natural Environment Research Council.

Relationships between species that evolve closely together can be fragile, leading to biological communities that can be easily disrupted by climate change. However, the new study suggests that, at least for these insects, the predator-prey relationships are less fragile and are resistant to disruption. Despite this, modern environments are much more fragmented than those in the past, making all natural communities more sensitive to change.

Dr Schönrogge, an ecologist at CEH, said, "The ranges of many species that interact with others, as mutualists, competitors or in predator-prey relationships, are changing and so is the composition of the communities they live in. This study suggests that, at least with some communities, species coming together due to environmental changes actually had some shared, possibly long past, history and thus interact more efficiently than one might otherwise expect."

Professor Graham Stone of the University of Edinburgh's School of Biological Sciences, who led the study, said, "Insects account for more than half of all animal species found on Earth. Interactions between insects, and between insects and other kinds of organism, fulfil many important biological roles including crop pollination and pest control. We hope that our study will improve understanding of how interactions between modern species may respond to climate change."

Additional information

The full paper reference is “Reconstructing Community Assembly in Time and Space Reveals Enemy Escape in a Western Palearctic Insect Community”, Current Biology, 2012. Graham N Stone, Konrad Lohse, James A Nicholls, Pablo Fuentes-Utrilla, Frazier Sinclair, Karsten Schönrogge, György Csoka, George Melika, Jose-Luis Nieves-Aldrey, Juli Pujade-Villar, Majide Tavakoli, Richard R Askew, Michael J Hickerson.

The University of Edinburgh issued a press release for this story.




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