Mutations have greatly benefited mankind
OPINION
AWellington man claims that every mutation reduces the effectiveness of DNA. An evolution denier, he implies that, with ever dwindling DNA, evolution cannot continue or progress.
Mutation is widely misunderstood. Nearly every cell in your body undergoes mutations every day, but the mutations have no effect whatsoever. Geneticists say these mutations are neutral.
We are fortunate in being equipped with very effective molecular repair kits whose job is to proofread the three-billion-word DNA molecule as it makes copies of itself. These kits spot mutations, or DNA spelling mistakes, and correct them.
But not only in people. All plants, animals and microbes mutate. An English geneticist calculates that each one of the bacterium E coli’s 4000 genes in human guts mutate harmlessly 2 billion times a day. Flu viruses perpetually mutate to produce new strains every year, and bacteria are perpetually mutating to produce resistance to antibiotics.
Occasional mutations play havoc and make us colour blind, or into dwarfs, albinos, or haemophiliacs. On the other hand, some mutations have done wonders for humanity.
A mutation in our FOXP2 gene about 50,000 years ago helped give us the power of speech. Gene ASPM mutated in humans 15,000 years ago to increase the size of our brains. About 7500 years ago another mutation happened that enabled us to digest milk for the first time without falling ill.
Mutations sometimes double or quadruple the size of DNA in plants and animals.
Apples and bananas once mutated to have twice as much DNA as their wild ancestors. Tobacco and cotton plants have four times as much DNA as their wild ancestors. In fact, 99 per cent of ferns, 80 per cent of grasses and more than 50 per cent of flowering plants have more DNA than their forbears (a condition known as ‘‘polyploidy’’).
Long ago, mutations more than quadrupled the DNA in fishes’ tadpole-like ancestors. Fish used the extra DNA to make bony skeletons, skulls, jaws and paired fins for the first time. Today a lot of Americans eat polyploid oysters and salmon that are bigger and fatter than their wild forbears.
What about all the mutations that happened after Hiroshima and Nagasaki or Chernobyl? Endless UN checks and surveys of children and grandchildren born to the survivors of the bombs or Chernobyl reveal that mutations are so low they are almost indistinguishable from children in other parts of Japan and Russia. Displacing those people from Chernobyl has done far more psychosocial damage than the radiation.
Although large areas around Chernobyl and Fukushima are now free of radiation, the displaced populations don’t want to return despite several women who refused to move living healthily near Chernobyl.
The trouble is, misplaced fear, trepidation and misunderstandings about radiation and its attendant mutations can lead to vastly expensive and futile undertakings, and misery among thousands of needlessly displaced residents.