A Col­lec­tion of News by Moos


Cli­mate change and coevo­lu­tion mod­elled to pre­dict the fate of species

pub­lished 26 Octo­ber 2013 | mod­i­fied 26 July 2014

When sci­en­tists attempt to under­stand how cli­mate change might reshape our envi­ron­ment, they must grap­ple with the seem­ingly end­less com­plex­ity of inter­act­ing sys­tems. For those con­sid­er­ing the likely fate of par­tic­u­lar species, there is now a rel­a­tively sim­ple rule of thumb to help cal­cu­late the likely effect of cli­mate change where species interact.

figure cc coevolution modelResearch pub­lished on 22 Octo­ber in PLoS Biol­ogy argues that where species have con­flict­ing inter­ests (for exam­ple where one species becomes very aggres­sive towards the species it com­petes with for food) their coe­volv­ing rela­tion­ship is likely to reduce the effects of cli­mate change on both species. Where species inter­act in a non-​conflicting way (for exam­ple where one species sim­ply avoids the other species it com­petes with for food, rather than becom­ing aggres­sive) the effects of cli­mate change are likely to be greater.

A lot of the dis­cus­sion about cli­mate change focuses on the fate of indi­vid­ual, iconic species, but to eval­u­ate the effects of future envi­ron­men­tal changes we need to account for inter­ac­tions between species
Tobin North­field, evo­lu­tion­ary ecol­o­gist, James Cook University »

“We need to con­sider how species coe­volve – how they are adapt­ing in response to each other, as well as in response to cli­mate change. In addi­tion, as dif­fi­cult as it may seem, we need to account for chang­ing inter­ac­tions, as the species evolve.”

Dr North­field, now at James Cook Uni­ver­sity in Cairns, worked at the Uni­ver­sity of Wis­con­sin with Dr Anthony Ives to develop a rule of thumb to help sci­en­tists cal­cu­late how coe­volv­ing species might change over time. “When eval­u­at­ing the effects of cli­mate change, there is already so much to con­sider, we were hop­ing to find some sim­ple answers,” Dr North­field said.

Drs North­field and Ives have devel­oped mod­el­ling tools and guide­lines to help sci­en­tists extrap­o­late from the short to longer term. “Many ear­lier stud­ies have looked at how cli­mate change might affect the evo­lu­tion of par­tic­u­lar species, and more recently there has been some inves­ti­ga­tion of how inter­act­ing species might change in the short term.”

“We used sim­ple mod­els of com­pe­ti­tion, pre­da­tion and mutu­al­ism to con­sider how these inter­ac­tions might change over longer time peri­ods, and how that, in turn will affect each species,” Dr North­field said. “The nature of cli­mate change means that we don’t have years and cen­turies to observe changes in nature. Math­e­mat­i­cal mod­el­ling gives us a way to cal­cu­late what the future might look like,” he said.

The study began, with fund­ing from the United States Depart­ment of Agri­cul­ture, as an inves­ti­ga­tion of how pest insect pop­u­la­tion den­si­ties might change in crop­ping regions. “One of our find­ings is that when preda­tors attack crop pests and ben­e­fit agri­cul­ture, such as lady bee­tles eat­ing aphids, the preda­tor and prey will both evolve in response to cli­mate change and will reduce the effect of cli­mate change on crop dam­age,” Dr North­field said.

The researchers have sug­gested ways to eval­u­ate their rule of thumb.

“Insect pop­u­la­tions are a good test­ing ground for our the­ory, because it is rel­a­tively easy to include many insects in an exper­i­ment, and they repro­duce quickly, allow­ing faster evo­lu­tion,” Dr North­field said. “For exam­ple, by look­ing at insect/​plant inter­ac­tions at dif­fer­ent lat­i­tudes, it is pos­si­ble to observe how coe­volv­ing species, and their inter­ac­tions, vary in dif­fer­ent cli­matic conditions.

“If you know what type of coevo­lu­tion dri­ves the inter­ac­tion, you can make pre­dic­tions of how it will affect the species den­si­ties across the dif­fer­ent latitudes.”

The paper also sug­gests ways for researchers to deter­mine which type of coevo­lu­tion (con­flict­ing or non-​conflicting) dri­ves a par­tic­u­lar species inter­ac­tion. “This is not as clear and straight­for­ward as you might think,” Dr North­field said. “In some plant – insect rela­tion­ships, for exam­ple, some insects that pol­li­nate flow­ers can also evolve to steal from the flower with­out pro­vid­ing the flower with the ben­e­fits. Of course, this con­flicts with what is best for the plant. So we’ve also devel­oped some guide­lines for clas­si­fy­ing species interactions.”

(Source: James Cook Uni­ver­sity media release, 24.10.2013)

Goal: 7000 tigers in the wild

Tiger range countries map

Tiger map” (CC BY 2.5) by Sander­son et al., 2006.

about zoos and their mis­sion regard­ing breed­ing endan­gered species, nature con­ser­va­tion, bio­di­ver­sity and edu­ca­tion, which of course relates to the evo­lu­tion of species.
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