Stickleback virtual lab

A year research project has uncovered some of the genetic rules that allow organisms to adapt rapidly to new environments. By Robert Sanders. That experiment has been performed naturally tens of thousands of times over millions of years as sea-faring threespine sticklebacks — which, like salmon, travel up rivers to spawn — have gotten stranded in lakes and had to evolve as permanent denizens of fresh water.

Michael Bell, currently a research associate in the University of California Museum of Paleontology at UC Berkeley, stumbled across one such natural experiment in in Alaska, and ever since has been studying the physical changes these fish undergo as they evolve and the genetic basis for these changes. He has even created his own experiments, seeding three Alaskan lakes with oceanic sticklebacks in , and in order to track their evolution from oceanic fish to freshwater lake fish.

Stickleback genetics

This process appears to occur within decades — very unlike the slow evolution that Charles Darwin imagined — providing scientists a unique opportunity to actually observe vertebrate adaptation in nature. The study, led by Bell, Krishna Veeramah at Stony Brook University and David Kingsley of Stanford University, sheds light on which genetic changes may underlie the evolutionary response to natural selection in other species.

Threespine sticklebacks are like salmon: they live in the ocean and swim up freshwater streams to spawn. But tens of thousands of times over the past 10 million years, groups have been stranded in lakes at the upper reaches of streams around the Northern Hemisphere and had to adapt to live permanently in freshwater. Most such populations have relied upon the same genes to adapt, and usually within a decade.

Photo courtesy of Michael Bell.

Stickleback evolution lab answers

Bell and his colleagues collected threespine sticklebacks Gasterosteus aculeatus from three of the Alaskan lakes each year and performed whole genome sequencing to track how their DNA evolved during adaptation to freshwater. They found hundreds of underlying genomic changes that form the basis of their rapid adaptation. While the predictability of evolution is not an exact science, the authors believe their understanding of how the stickleback colonizes fresh water provide important insights into the genomics behind vertebrate evolution and provides insight into how evolution might proceed species-wide in the future.

Bell has been enamored of sticklebacks since the summer after his freshman year at UC San Diego, when he collected fossil sticklebacks in Nevada. Michael Bell at Lobeck Lake in Alaska this year, where 31 years ago he stumbled across threespine sticklebacks that had been reintroduced to the lake and offered a rare opportunity to conduct a long-term study of evolutionary adaptation.