Saturday, December 10, 2016

Eastern Killifish Evolve to Handle More Pollution

Killifish of Eastern America have been found surviving pollution levels thousands of times over the typical tolerance levels, compared to a fee decades ago. Significant evolutionary changes have occurred in the killifish in only about half a century to allow them to tolerate such polluted conditions. The time frame of 50 years is impressive, since many people tend to think evolution takes millions of years. In fact this extremely rapid change is only possible when a species has immense diversity. Organisms that lack diversity can cope only with gradual, slow paced changes.
The increased trend in pollution, as well as the growing availability of genomic sequencing, there has been more ecological studies that employ these methods to find exact mutations leading to the successful mutations in question. This killifish exhibits alterations in the genome affect the AHR pathway which is related to the immune system and oestrogen signalling. Usually, this pathway is triggered by natural toxins, but the pollution can also trigger responses in young killifish leading to detrimental effects and death in young killifish. The mutation helps make this pathway more selective to avoid being active in young fish.

Links:
https://www.newscientist.com/article/2115635-fish-rapidly-adapt-to-pollution-thousands-of-times-lethal-levels/ 
http://science.sciencemag.org/content/354/6317/1305  

1 comment:

  1. It is quite impressive how the killfish have evolved in a short amount of time in order to survive such harsh conditions of pollution. Talk about "survival of the fittest" in action. With constant rise in pollution globally, it's a concerning issue to think about in terms preserving and saving wildlife from pollution. Of course, our work might be a little bit easier if all organisms can adapt and evolve quickly like the killfish have in order to survive.

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