Evolving Understanding of Evolution

By SAM URETSKY

According to the Washington Post, now Vice President Mike Pence, speaking before Congress on July 11, 2002, said “Charles Darwin never thought of evolution as anything other than a theory. He hoped that someday it would be proven by the fossil record but did not live to see that, nor have we … And now that we have recognized evolution as a theory, I would simply and humbly ask, can we teach it as such and can we also consider teaching other theories of the origin of species?”

Politicians of both parties have tried to deny evolution, or at the least found excuses for claiming ignorance, usually “I’m not a scientist,” but evolution is too well documented, not simply by fossil records but in ongoing biologic observation, to be denied. Mutation, migration (gene flow), genetic drift, and natural and artificial selection are recognized methods of change. Mutation and natural selection are generally understood concepts, although Marvel comics’ X-Men may have confused many people’s understanding of mutation.

The University of California at Berkeley maintains a valuable web site dedicated to evolution, which defines gene flow as “The movement of genes between populations. This may happen through the migration of organisms or the movement of gametes (such as pollen blown to a new location).”

Genetic drift is largely due to chance, where some genes reproduce themselves more quickly than others, while others may reproduce more slowly and fall out of a population. What is relevant is that evolution is an ongoing process. Usually a new species remains alive if the change provides a survival advantage, and that creates a problem that we’re seeing increasingly today.

A species is most likely to evolve if it has a short reproductive period. Bacteria, which have a rapid reproduction rate, have evolved to become resistant to antibiotics. According to the Centers for Disease Control and Prevention (CDC), “Each year in the United States, at least 2 million people become infected with bacteria that are resistant to antibiotics and at least 23,000 people die each year as a direct result of these infections.” While there are efforts to develop new antibiotics, the current focus is on education and prevention of infection.

In September 2010 the journal Microbiology and Molecular Biology News published a review article, “Origins and Evolution of Antibiotic Resistance.” The authors wrote: “Antibiotics have always been considered one of the wonder discoveries of the 20th century. This is true, but the real wonder is the rise of antibiotic resistance in hospitals, communities, and the environment concomitant with their use. The extraordinary genetic capacities of microbes have benefitted from man’s overuse of antibiotics to exploit every source of resistance genes and every means of horizontal gene transmission to develop multiple mechanisms of resistance for each and every antibiotic introduced into practice clinically, agriculturally, or otherwise.”

Bacteria evolved as a result of antibiotics; plants evolved as a result of herbicides. This has been a particular focus of the Union of Concerned Scientists, which has published a series of reports, “Monsanto’s RoundupReady and Bt technologies lead to resistant weeds and insects that can make farming harder and reduce sustainability.”

Simply, genetically modified crops were commercially adopted more rapidly than any other agricultural technology. The Harvard blog, “Science in the News,” had a discussion of the role of Monsanto’s RoundupReady system. The crops themselves were modified to be resistant to Monsanto’s Roundup brand herbicide. Then, farmers could plant Roundup-ready crops, spray the area with Roundup and kill the weeds while the crops were unaffected. It was an excellent system with benefits that reduced soil runoff and herbicide toxicity – until resistant weeds evolved.

Similarly, Monsanto developed Bt crops that produced their own pesticides. By the concept of survival of the fittest, the insect pests that were most tolerant of these crops survived and reproduced with each generation growing increasingly resistant. Today there are 500 species of insects with some degree of herbicide resistance. The two best known are the Corn Rootworm found in the United States and the Pink Bollworm seen in India since 2009.

Michigan State University explains how pesticide resistance develops: “Repeated use of the same class of pesticides to control a pest can cause undesirable changes in the gene pool of a pest leading to another form of artificial selection, pesticide resistance. When a pesticide is first used, a small proportion of the pest population may survive exposure to the material due to their distinct genetic makeup. These individuals pass along the genes for resistance to the next generation.” Scientists, from universities, government, and even Monsanto, are glad to share the information on how to avoid unwanted evolution.

But Pew Research reported that a minority of Americans fully accept evolution through natural selection. Over six in ten US adults (62%) say humans have evolved over time. But only a little more than half of those who believe in evolution express the belief that humans and other living things evolved solely due to natural processes. A Pew report issued in honor of Darwin Day stated “A quarter of US adults (25%) say evolution was guided by a supreme being. The same survey found that 34% of Americans reject evolution entirely, saying humans and other living things have existed in their present form since the beginning of time.”

Politicians don’t believe in evolution. What more is there to know?

Sam Uretsky is a writer and pharmacist living in New York. Email sdu01@outlook.com.

From The Progressive Populist, July 1-15, 2017

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