Located in Newark, the Diamond Alkali Superfund Site shows evidence of an astonishing evolutionary feat. The Environmental Protection Agency (EPA) alerts us of the dangers that exist at this former chemical manufacturing plant; remnants of “Agent Orange” and DDT plague the area. The animals inhabiting the surrounding waters have taken up these chemicals and remarkably have survived. A recently published study states that the Atlantic killifish has been able to overcome the toxic waters by adapting at an incredible rate due to the nucleotide diversity of the species. The fish have developed without a harmful pathway that can be triggered by polychlorinated biphenyls. Since this pathway cannot be activated, the adults and their embryos are able to survive PCBs levels thousands of times higher than fish that have the pathway — evolution at its finest.
The Mummichog, as it’s frequently referred to, is a common fish found around the Lower Passaic River and Newark Bay areas. And since the late 1990s, researches have found evidence of the species becoming tolerant to the polluted water of the Lower Passaic Superfund site and other locations along the Atlantic.
Over the course of a few decades, independent populations of the fish have developed similar genetic adaptations. The key point made by the study, through the genomic analysis of 384 killifish, was that evolution does not necessarily have to occur at a single, particular place to be repeated. From these findings, researchers are able to have concrete examples of how animals can respond effectively to the rate of change taking place in the environment.
The Anthropocene has been characterized by unprecedented transformation. I will continue to wonder how species will respond to the ever-evolving world, if we are even capable of doing so. Researchers studying the Atlantic killifish are curious about the same thing. They next ask the question, “What will happen to the population when waters finally become clean?” It is evident, however, a species like the killifish is poised to take on whatever trouble comes its way.