May 2, 2019 — In comic books, falling into a vat of toxic chemicals can give you super powers. The same is sort of true for one species of fish – with help from a superhero relative.
The 15-centimetre-long Gulf killifish (Fundulus grandis) lives in estuaries around the Gulf of Mexico, some of which are heavily polluted. They survive levels of toxic halogenated and polycyclic aromatic hydrocarbons (HAHs and PAHs) that cause lethal deformities in other animals. The killifish in these regions have evolved resistance in less than 60 years.
To discover how they did it, Elias Oziolor of Baylor University in Texas and colleagues compared the genomes of the toughest fish with those from less polluted areas. They found that many of the genetic variants conferring resistance come from a related species, the Atlantic killifish or mummichog (Fundus heteroclitus) – an astonishingly tough fish that has evolved resistance to many pollutants.