Those elusive beneficial mutations

September 9, 2021 by No Comments

Naturalists claim that evolution is driven by beneficial mutations. Is that a plausible explanation for the diversity found in nature? We’ll see.

Induced mutations

Thomas Morgan and Herman Muller, leading geneticists, carried out a lengthy study of fruit flies (drosophila) looking for traces of evolution. But generation after generation, flies that didn’t cooperate refused to evolve. They eventually solved the problem, or at least they thought they had. They subjected a pure strain of fruit flies to chemical and radiation treatments. The result was mutilated flies. The flies developed yellow, brown, or purple eyes; or bulging, flat, or dented eyes. Some flies had no eyes.

Other anomalies appeared. The flies came with fine or coarse hair, or with curly or tousled hair. On the other hand, some were bald. Some flies did not have antennae. The variation in their wing patterns was striking. Some wings were wide, others were truncated. From time to time, the wings were so small that the fly could not fly. There were large flies, small flies, active flies, and lazy flies. The list of rarities goes on.

These mutilations were hailed as a success. Many naturalists claimed that the matter was resolved once and for all. Mutation is the driving force behind evolution.

Everyone agrees that mutations occur in nature. And these geneticists demonstrated that by means of chemicals and radiation, man could induce mutations. But to say that mutations result in new life forms is an entirely different matter. The fruit fly experiments certainly don’t prove it.

Consider the facts. Most of the induced mutations killed the subjects. Some died immediately; others had a shorter life expectancy. If the fly survived, it was often sterile or its young were too weak to survive. Mutations that were not harmful were neutral at best and produced only trivial results. Neither of the mutations could honestly be called beneficial.

These experiments went on for 17 years. What did they really show? Little more than we already knew. That is, all living things reproduce according to their own species. Regardless of how those fruit flies have been treated or abused, the only thing they are going to produce is other fruit flies. It doesn’t seem to matter how many generations are observed.

Considering a new generation of fruit flies mature in less than two weeks, the geneticists in the “fly” room studied more than 442 generations of fruit flies in 17 years. They did everything they could think of to make them evolve into something else. They did not.

Here’s a question for you: do you think those scientists would have abandoned their 17-year project if they still had any hope of designing a new species? No, I don’t think they would either. Perhaps the most important lesson to be learned from the fruit fly experiment is the remarkable stability of this species.

Another question: if positive or beneficial mutations are the driving force behind evolution, why couldn’t the “fly” room present a single unequivocal positive mutation in 17 years and 442 generations of experiments?

Natural mutations

What do we know about the genetic mutations that affect humans? According to Reader’s Digest, ABCs of the Human Body, scientists have identified 1,800 diseases transmitted by faulty genes. They claim that of all babies born alive today, an estimated 0.7 percent suffer from a genetic defect inherited from the parents.

But those are the ones who live. Other genetic disorders cause spontaneous abortions. They are dead on arrival and few records and, for the most part, no records are kept.

In the face of 1,800 known genetic disabilities, plus an unknown number of fatal birth defects, what can we put on the bright side of the human mutation ledger? Not much. Believe it or not, the best example geneticists can find is sickle cell anemia. That, we know, is a genetic error that, without medical treatment, often leads to death.

That doesn’t sound very beneficial, does it? But in a way it is.

Sickle cell anemia is found in those parts of Asia and Africa where a severe form of parasite malaria was and largely remains endemic. Those individuals with a chromosome, either from the father or the mother, who are carriers of sickle cell disease are immune to both malaria and sickle cell disorder.

On the other hand, those who receive two copies of the sickle cell trait, one from each parent, usually die prematurely from anemia. As you can see, it is a mixed blessing.

Skin pigmentation is occasionally cited as an example of a beneficial mutation. Most authorities do not agree. They believe that the original population had a variety of genes that allowed for a wide range of pigmentation. The intense sunlight from the equator favored those with greater pigmentation. The less intense sunlight in the northern regions favored those with less pigmentation.

If that’s the case, then we can attribute the pairing of the various populations to natural selection, however mutations have nothing to do with that.

Neither sickle cell anemia nor skin pigmentation turns out to be a credible example of beneficial mutations. The harmful effects of mutations are obvious, but where are the positives?

The World Almanac tells us that the world’s population numbered around 200 million people in 1 AD. By 1650 that figure rose to 500 million; 200 years later, that number doubled (1850: one billion); it doubled again in 1930 (2 billion); it doubled again in 1975 (4 billion); and in 2000 it reached the level of 6 billion people.

From 4,000 a. When the Sumerians began to keep records called pictograms on clay records to this day, we have had approximately 6,000 years of recorded history. Several billion people have populated the world during this period. It is interesting to note that, throughout all this time and with all these generations, not a single example of an unqualified beneficial mutation has emerged in humanity.

If we broaden our scope to include plants and animals, nature has not provided us with any obvious permanent positive mutation there either. We did not find observations of one species mutating into another. And we found no eyewitness accounts of any plant or animal developing a new organ, internal or external.

We are told that the roughly two million species of life slowly evolved into their current complex configurations through a series of thousands, perhaps millions of genetic errors.

All those positive mutations that propelled single-celled organisms into redwoods, elephants, and whales occurred sometime in the misty dawn before man’s watch began. Since humans arrived on the scene to record the achievements of evolution, it has done little more than make some minor and superficial adjustments to some species.

The vast majority have not changed at all.

Naturalists have a simple answer to this criticism. “Six thousand years is too short a time to see the progress of evolution.” Maybe. But that sounds hollow. If beneficial mistakes are really the creative force that has made every living thing what it is, then it is reasonable to expect some simple examples to emerge somewhere in six thousand years, two million species, and incalculable opportunities in the form of people. animals and plants.

But none have surfaced. Evolution must have been on vacation for the last six thousand years.

Question to consider: Could it be that positive mutations have not been observed because they simply do not occur?

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