No evolution in pollution: killifish survivors are ‘losers’ | 2/13/2019 | David Catchpoole
Click For Photo:

Creation 39(4):12–13, October 2017

When researchers compared the genomes of pollution-tolerant killifish and killifish in nearby unpolluted waters, they found a key difference.4 The pollution-tolerant fish had a common set of mutations. Further analysis showed that in mutant fish, many of those mutations help to deactivate, or turn off, the aryl hydrocarbon receptor signalling pathway. This molecular pathway is responsible for a lot of the abnormal development and larval lethality in normal killifish when polluting contaminants are present. So because the mutated genes turn off that biochemical pathway, mutant killifish can safely live in what would otherwise be toxic waters.

Researchers - Set - Mutations - Living - Waters

The researchers also discovered that the set of mutations could be found in some of the killifish living in unpolluted waters. However, they say that the fact it was rare there probably indicates these mutations don’t provide any survival advantage for fish when toxins are absent.

However, there is nothing ‘evolutionary’ in what the researchers observed and documented, in the sense of any evidence of mutation-derived increase in genetic information as microbe-to-man evolution requires. The killifish mutations were already present in the clean-water populations, ready for natural selection to act upon when the environment turned toxic. (Natural selection can only act upon existing genetic information, it can never generate new genes, therefore natural selection is not evolution, despite what the bait-and-switch tactics5 of some textbooks imply.) The mutations did not gain any new function but rather lost function (the turning off of the aforementioned metabolic pathway). So the killifish survivors in polluted waters were actually ‘losers’.

Individuals - Researchers - Populations - Areas - Diversity

And not just as individuals. The researchers were concerned to see that killifish populations in contaminated areas had lost genetic diversity, compared to the original populations in clean water. As National Geographic put it, “In adapting to their new environment, the pollution-tolerant fish lost a little...
(Excerpt) Read more at:
Wake Up To Breaking News!
The beatings will continue until moral improves.
Sign In or Register to comment.

Welcome to Long Room!

Where The World Finds Its News!