Tiny Fish Rapidly Adapted to Cold Water. Was It Evolution? Show
BY * | TUESDAY, AUGUST 17, 2010 Researchers have found that tiny fish called sticklebacks can adapt rapidly to a decrease in water temperature. This discovery adds to a long and growing list of animal trait variations that happen quickly. The researchers cited the stickleback adaptation as an example of evolution in action, but the rapidity of this change identifies it as the result of intentional programming--not mindless mutations. The tiny stickleback seems to have a history of adaptability. A University of British Columbia press release indicated that populations of these fish once lived in the ocean, but then moved to live in freshwater lakes and streams.1 Other marine fish have been found with the ability to thrive in fresh water in only a few generations, like the pompano populations that are bred for freshwater fish farming.2 A team of Canadian and European scientists transplanted sticklebacks from Oyster Lagoon in southwest British Columbia to cold freshwater ponds. In just three years, which corresponds to three generations, stickleback fish "developed tolerance for" water that is 4.5 degrees Fahrenheit colder than the marine population's habitat.1 By the third generation, descendants remained of those "rare individuals" that already had the capacity to tolerate cold before the experiment began.1 The study authors wrote, "This rate of phenotypic evolution is among the most rapid to be observed in a natural population."3 But why were these fish able to adapt so quickly to colder waters? According to the researchers, "Our results suggest that cold tolerance is under strong selection and that marine sticklebacks carry sufficient genetic variation to adapt to changes in temperature over remarkably short time scales."3 But in considering this conclusion, it becomes apparent that the reference to "selection" is superfluous. All that is really needed for these fish to change as they did was for them to have the programmed instructions for "genetic variation" that the authors inferred from the data.3 It was the engineered genetic instructions, not nature's cold temperatures, that directed some offspring to develop slightly different traits in order for them to continue surviving. And engineered instructions are exactly what would be expected from an Architect who equipped His swimming creatures with what they would need to "be fruitful, and multiply, and fill the waters in the seas."4 References
* Mr. Thomas is Science Writer at the Institute for Creation Research. Article posted on August 17, 2010.
 Different genes code for two different forms of stickleback fish. Fish Adapting to a Changing WorldNews story originally written on October 8, 2008Scientists have been studying stickleback fish to learn more about how animals cope when their environment changes. Since the Earth is changing quickly because of global warming and other global changes, this research helps us understand how animals will adapt to a changing world. There are two main ways that the stickleback fish cope when their environment changes. First, individual fish can change the way they live their lives. Second, a whole population of animals can adapt over time through the process of microevolution by natural selection. Some stickleback fish live in the ocean while others live in freshwater. The fish that live in the ocean have bony plates and spines for protection. These plates help the fish survive attacks by birds and other predators. Freshwater stickleback fish usually don�t have the plates, and sometimes the spines, as shown in the illustration at the left. This change is due to the process of microevolution. For these fish, it can happen very rapidly, sometimes in only dozens of years. That�s fast for evolution. One hypothesis for why the freshwater fish no longer have the protective plates and spines is that they use their energy for growth and reproduction instead of plate production. The freshwater environment is stressful for the fish. Lakes become iced over, limiting the prey items available to stickleback throughout most of the winter, so growth and reproduction are probably better ways to survive. Of course, it is not up to an individual fish whether it grows plates and spines.� It is coded in a fish�s genes. Scientists have been studying the genes of the stickleback fish to learn which genes allow fish to develop lateral plates. They found the gene that codes for plate development. They called the gene Eda. However more gene mapping showed that in addition to Eda, two other blocks of the same chromosome were also linked to the growth of plates. Fish that had Eda and the other genes grew plates. Fish that had the recessive gene instead of Eda did not grow plates. Last modified February 6, 2009 by Lisa Gardiner. You might also be interested in:RiversRivers are very important to Earth because they are major forces that shape the landscape. Also, they provide transportation and water for drinking, washing and farming. Rivers can flow on land or underground...more Oldest Earth Mantle Reservoir DiscoveredThe Earth's mantle is a rocky, solid shell that is between the Earth's crust and the outer core, and makes up about 84 percent of the Earth's volume. The mantle is made up of many distinct portions or...more How are the ocean sticklebacks different from the lake sticklebacks?One difference is the amount of protective armor that covers their bodies: while oceanic sticklebacks have about 30 armor plates extending from head to tail, most freshwater sticklebacks have just a handful of plates that sit closer to the front of the body. Dr.
How did the sticklebacks come to live in lakes?The threespine stickleback is native to both coasts of the U.S. as well as Lake Ontario. It spread into Lake Michigan in the early 1980s, most likely as a result of ballast water, canals and bait-bucket transfers. It is now established in the other Great Lakes.
How did stickleback bodies change as they adapted to life in Postglacial lakes?[CARROLL:] Stickleback bodies changed in many ways as they adapted to life in post- glacial lakes. They got smaller, their coloring changed, and most strikingly, even their skeletons changed.
How did stickleback fish evolve?Pockets of sticklebacks were isolated by geologic changes at the end of the Ice Age 10,000 years ago, with each newly separated population evolving in response to local ecological conditions.
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How did stickleback fish change when they switched from living in the ocean to living in lakes?
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