Nav: Home

Evolution in action: How some fish adapt to pollutants

December 08, 2016

New genetic analyses of fish reveal how some have managed to evolve and adapt to live in polluted water. The results suggest that the high genetic diversity exhibited by these fish was key - a palette for natural selection to act on to facilitate the population's rapid adaptation to extreme pressures. In salt marshes along North America's Atlantic coast, killifish have increasingly been exposed to industrial pollutants that have reached lethal levels in recent decades. Some subpopulations have developed tolerance to the pollutants, however. To better understand this adaptation, Noah M. Reid et al. analyzed the genomes of 384 killifish, some of which have developed tolerance to toxins and some of which remained sensitive, across four regions. Tolerant fish were found to have reduced genetic diversity compared to sensitive fish - a sign of reduction in population size in polluted sites, where exchange of genetic information became limited. The researchers also identified in these fish a number of genes that were associated with increased survival, particularly genes involved in the aryl hydrocarbon receptor (AHR) signaling pathway. By examining this pathway in developing embryos exposed to toxins, the team found that many genes associated with the AHR pathway were deleted in tolerant killifish, likely impacting AHR signaling in a manner not observed in sensitive killifish. But as the AHR pathway is associated with estrogen and hypoxia signaling, regulation of cell cycle, and immune system function, what about the consequences of it being stifled? The authors identified several compensatory mutations that may help mitigate the loss of function in AHR signaling in killifish. These results are featured in a Perspective by Michael Tobler and Zachary W. Culumber.
-end-


American Association for the Advancement of Science

Related Natural Selection Articles:

Ongoing natural selection against damaging genetic mutations in humans
Investigators report that, as a species, humans are able to keep the accumulation of damaging mutations in check because each additional mutation that's added to a genome causes larger, and larger consequences, decreasing an individual's ability to pass on genetic material.
HIV co-infection influences natural selection on M. tuberculosis
While M. tuberculosis has been evolving with humans for thousands of years, HIV co-infections create host immunological environments that this bacterium has not encountered before and could, therefore, be nudging it to evolve new characteristics.
The selection of archaeological research material should be re-evaluated
A systematically collected material produces a more exact image of the excavated objects.
Climate change altered the natural selection -- large forehead patch no longer a winner
In a new study, researchers at Uppsala University have found evidence of that climate change upends selection of face characteristics in the collared flycatcher.
How natural selection acted on 1 penguin species over the past quarter century
University of Washington biologist Dee Boersma and her colleagues combed through 28 years' worth of data on Magellanic penguins to search for signs that natural selection -- one of the main drivers of evolution -- may be acting on certain penguin traits.
More is better when it comes to online product selection
Retailers should take advantage of the unlimited retail space online and offer everything they sell.
Selection pressures push plants over adaption cliff
New simulations by researchers at the University of Warwick and UCL's Institute of Archaeology of plant evolution over the last 3000 years have revealed an unexpected limit to how far useful crops can be pushed to adapt before they suffer population collapse.
Long-term response to selection predictable regardless of genetic architecture
In their latest publication in the Proceedings of the National Academy of Sciences (PNAS) Tiago Paixao, Postdoc, and Nick Barton, Professor at the Institute of Science and Technology Austria, addressed the controversial role of gene interactions (or epistasis), where the effect of one gene is affected by the presence of other genes, in the response to selection for two extremely different scenarios of evolutionary mechanisms.
Applying parameter selection and verification techniques to an HIV model
Physical and biological models often have hundreds of inputs, many of which may have a negligible effect on a model's response.
Evolutionary 'selection of the fittest' measured for the first time
A difference of one hundredth of a percent in fitness is sufficient to select between winners and losers in evolution.

Related Natural Selection Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Bias And Perception
How does bias distort our thinking, our listening, our beliefs... and even our search results? How can we fight it? This hour, TED speakers explore ideas about the unconscious biases that shape us. Guests include writer and broadcaster Yassmin Abdel-Magied, climatologist J. Marshall Shepherd, journalist Andreas Ekström, and experimental psychologist Tony Salvador.
Now Playing: Science for the People

#513 Dinosaur Tails
This week: dinosaurs! We're discussing dinosaur tails, bipedalism, paleontology public outreach, dinosaur MOOCs, and other neat dinosaur related things with Dr. Scott Persons from the University of Alberta, who is also the author of the book "Dinosaurs of the Alberta Badlands".