Fish has adapted quickly to lethal levels of pollution

According to a study led by the University of California, a fish has adapted and is thriving despite lethal level of pollution.

Many species cannot adapt to  the enviromental changes, but one of them seems thriving on it.
Atlantic killifish living in four polluted East Coast inlet is incredibly resilient.
This fish have adapted to ridiculous levels of  toxic industrial pollutants that would normally kill other fish.

The killifish is up to 8,000 times more resistant to this level of pollution than other fish,
the study says. While the fish is not commercially valuable, it is an important food for
other species and an environmental indicator.

Genetic diversity speeds evolution

What makes Atlantic killifish so tough and adaptable? Extremely high levels of genetic variation,
higher than any other species measured so far. The more genetic diversity, the faster they can evolve.
That’s the reason why insects and weeds can quickly adapt and evolve to resist pesticides,
and why pathogens can evolve quickly to resist drugs created to destroy them.

Though, not all species are so adaptable.

“Some people will see this as a positive and think, ‘Hey, species can evolve in response to what we’re doing to the environment!’
” said lead author Andrew Whitehead, associate professor in the UC Davis Department of Environmental Toxicology.
“Unfortunately, most species we care about preserving probably can’t adapt to these rapid changes because they don’t have the high levels of genetic variation that allow them to evolve quickly.”

Evolution a pollution solution? Not for most of us

I n the study,  scientists sequenced complete genomes of  400 Atlantic killifish from polluted and also non-polluted areas
at New Bedford Harbor in Massachusetts; Newark Bay, New Jersey; Connecticut’s Bridgeport area; and Virginia’s Elizabeth River.
The sites have been polluted since the 1950s and 1960s by  many industrial pollutants.

The team’s genetic analysis suggests that the Atlantic killifish’s genetic diversity make them unusually well
adapted, because they can learn to survive in radically altered habitats. At the genetic level, the studied populations evolved
in very similar ways, which suggests that these fish already carried the genetic variation that allowed them to adapt
before the sites were polluted, and  that there may be only a few evolutionary solutions to pollution.

The study lays the groundwork for future research that could explore which genes converse tolerance of specific chemicals.
Such work could help better explain how genetic differences among humans and other species may contribute to differences
sensitivities to environmental chemicals and pollutants.

“This study shows that different populations of Atlantic killifish exposed to toxic pollution evolve tolerance
to that pollution through changes in one molecular pathway,” said George Gilchrist, program director in the National
Science Foundation’s Division of Environmental Biology, which funded the study along with the National Institute of
Environmental Health Sciences. “This pathway may play a similar role in many animals exposed to pollutants,
because of slightly different adaptations in response to different toxicants.”


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