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A new study shows that sticklebacks can quickly evolve to deal with colder water (marine male stickleback, pictured).  (Source: Rowan Barrett, UBC)

A male (bottom) and female (top) stickleback get friendly with each other. Perhaps they're preparing to help the evolutionary cause?  (Source: Rowan Barrett, UBC)

UBC researchers wrangle some sticklebacks out on the pond.  (Source: Rowan Barrett, UBC)
Observed evolution recreates a natural process that occurred over the last 10,000 years

Life in the cold freshwater lakes of northern Europe, northern Asia, Canada, and Alaska is challenging for unprepared lifeforms.  Fortunately marine sticklebacks came equipped with a power tool -- evolution -- which allowed them to adapt and colonize this chilly environment.

Researchers at the University of British Columbia, along with colleagues from Switzerland and Sweden, "recreated history" by transplanting marine sticklebacks to freshwater ponds.  Within only three generations -- or roughly three year's time -- the little fish had evolved mechanism to cope with the 2.5 °C colder water.  The resultant population was roughly equivalent to the naturally evolved freshwater sticklebacks in terms of temperature tolerance.

A similar process is thought to have given rise to the first freshwater sticklebacks, which are thought to have diverged from marine sticklebacks 10,000 years ago.  At the end of the last ice age melting glaciers produced lakes and streams in the northern landmasses.  Sticklebacks slowly colonized these new bodies of water, adjusting to the colder temperature of their new home.

Rowan Barrett, a researcher with the UBC Department of Zoology and lead author of the work,states, "By testing the temperature tolerance of wild and lab-raised sticklebacks, we were able to determine that freshwater sticklebacks can tolerate lower temperatures than their marine counterparts.  This made sense from an evolutionary perspective because their ancestors were able to adapt to freshwater lakes, which typically reach colder temperatures than the ocean."

Barret, a new Ph.D, adds, "Scientific models have suggested that climate change could result in both a general, gradual increase of average temperatures and an increase in extreme temperatures.  Our study is the first to experimentally show that certain species in the wild could adapt to climate change very rapidly – in this case, colder water temperature. However, this rapid adaptation is not achieved without a cost. Only rare individuals that possess the ability to tolerate rapid changes in temperature survive, and the number of survivors may not be large enough to sustain the population. It is crucial that knowledge of evolutionary processes is incorporated into conservation and management policy."

Climate change is a popular topic right now, as the research community widely leans towards the hypothesis that the world is warming right now.  Thus the UBC study seems particularly interesting and pertinent as it shows that animals will likely evolve to adjust to the Earth's warmer conditions, if the Earth is indeed warming.

While some believe that the case for evolution is weak, there is ia vast body of evidence including field biology (direct observation), genetics, botany, morphology, paleontology, and biochemistry that indicates it's a virtual certainty that nature has employed and will continue to employ this essential asset.

Sticklebacks were among the first examples of creatures directly observed to have evolved significantly.  
E. Coli are another such model organism that has showed the ability to evolve significant new abilities in a brief amount of time.

The new work is reported in the peer-reviewed journal 
Proceedings of the Royal Society B.





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