Sticklebacks fast genetic response to pollution-hope for us

You might think some people can change their minds quickly, but the stickleback fish may be the first organism we have fund to change genes to improve its survival changes in a new environment, There may be hope for us all. Sticklebacks also seem to choose the head fish in their school by color and shape. Does this make them fickle fish?faroe_stamp_248_stickleback_gasterosteus_aculeatus

Seems that color and robustness of the males is critical during breeding season. During late March and early August the male stickleback’s throat and belly become a bright orange-red, his eyes turn bright blue and silvery scales appear on his back. These colors act as a warning to other males to stay out of my turf and it attractive to females.

There are two forms of the stickleback: the oceanic and the freshwater type. The oceanic form lives in the ocean and comes into shallow estuarine or freshwater rivers and streams to breed. Oceanic stickleback is protected by a complete set of bony lateral plates along the sides and dorsal and pelvic spines on the top and bottom of the fish. While freshwater stickleback usually lose the lateral plates, and sometimes the spines. The fresh water species has repeatedly developed from its ocean cousins but lives its entire in freshwater habitats

This evolutionary change occurs rapidly, sometimes it only takes a few decades verses 100s to 1000s of years for other animal’s evolutionary trait changes. “The stickleback has managed to evolve in full-speed reverse to cope with the cleanup of Lake Washington, according to a study led by researchers at Seattle’s Fred Hutchinson Cancer Research Center.gasterosteus-aculeatus1

The findings published in the journal Current Biology documents a rare example of an animal reverting to an earlier evolutionary version to survive a rapid change in its environment, according to the senior author of the paper, Catherine Peichel, a Hutchinson Center researcher.

“Just five decades ago, Lake Washington was notoriously polluted, full of murky water festering with blue-green algae that thrived on the millions of gallons of raw sewage cities pumped into it. Pollution cut visibility in the water to only about 30 inches. And that was great for the stickleback, a rugged-looking customer with three sharp spines along its back, because it easily could hide in the murk from its primary predator, cutthroat trout.

After $140 million cleanup of the lake launched in the 1960s, Lake Washington is swimmable again, and visibility reaches 25 feet.

Researchers discovered that in the space of four decades, the stickleback evolved backward, to an earlier version of the species that had full-body plating. Those ancestors were marine stickleback, a spiny, armor-plated species that invaded freshwater around Puget Sound as the glaciers retreated some 10,000 years ago.

Over time they evolved to shed the bony plating covering their bodies from snout to tail. By the 1960s, only about 6 percent of sticklebacks in Lake Washington were fully plated.

Fast-forward to today, though, and about 49 percent of the stickleback sampled for the study were fully plated, the researchers found. And 35 percent were partially armored.

Researchers surmise that is because marine versions of the fish, with armored plates, invaded the lake anew when the fish ladder was put in, mixing their genes with the unplated fish.

So, when the water was cleaned up, the fish were able to tap those genes to zoom backward to their earlier, plated version, and armor themselves against the cutthroat trout that suddenly could see — and eat — them.

How did the fish adapt so quickly and easily? The researchers say it’s because of their rich genetic variation.

That enabled them to cope with a range of environments and the changing conditions of the lake. In fact, they said, it looks like much of the change has happened in less than a decade.

It’s hoped the findings will help scientists learn more about the workings of human genetics and adaptation, Peichel said.”

Stickleback Fish May Teach Us Lessons In Adaptation – Lynda V. Mapes Seattle Times

May 16, 2008 http://www.flmnh.ufl.edu/fish/InNews/stickleback2008.html
Fitness In A Changing World: Genetics And Adaptations Of Alaskan Stickleback Fish

Science Daily October 22, 2008
http://www.sciencedaily.com/releases/2008/10/081010100457.htm

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2 Comments

  1. November 13, 2008 at 9:58 pm

    […] You might think some people can change their minds quickly, but the stickleback fish may be the first organism we have fund to change genes to improve its survival changes in a new environment , There may be hope for us all. … Original post […]

  2. November 14, 2008 at 7:42 am

    […] Sticklebacks fast genetic changes hope for usIt’s hoped the findings will help scientists learn more about the workings of human genetics and adaptation, Peichel said.” Stickleback Fish May Teach Us Lessons In Adaptation – Lynda V. Mapes Seattle Times May 16, 2008 … […]


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