Did we observe Evolution when killfish were able to start living in polluted waters?
“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’.
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 bit of their genetic capital: They became slightly less diverse.”1”
Read more here: https://creation.com/pollution-killifish