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Natural selection: constantly testing.

Evolution, commonly defined as changes in gene forms in a population over time, is all about making the grade: testing differences and promoting those that succeed. However, apply evolution to people, and it becomes evident that there's much more to being human than sheer biology. Influential neuroscientist Antonio Damasio offers a parallel when arguing that the interplay between mind and brain makes us human; "the emergence of consciousness" in people, he writes, "opened the way to a life worth living." (1)

Similarly, our ability to make choices means that we need not accept the premises and implications of social Darwinism, the misguided political view, arising from a misunderstanding of evolution, implying that injustices are acceptable because all such differences are natural and even ineluctable. Indeed, the capability to move beyond what some might consider biological determinism is also something uniquely human and further demonstrates how we make the grade as a species.

Laying groundwork

As thoughtful as Charles Darwin was, he never anticipated that his concept would be refrained in this manner. After worrying for some 20 years about the response he might receive, Darwin was pushed to go public with his evolutionary ideas when a letter from Alfred Russel Wallace arrived at his home in June 1858. In his mid-30s, Wallace was a struggling young naturalist who had been sharing his research with Darwin regularly. Wallace's latest note included a draft manuscript outlining his views on evolution. That manuscript sent Darwin, approaching 50, into a state somewhere between panic and depression because what Wallace outlined was remarkably similar to what Darwin had independently postulated.

Darwin feared that his decades-long hesitancy had cost him scientific priority and that Wallace would receive sole credit. (And receiving credit, simply stated, is itself a type of making the grade.) Shrewd colleagues came to Darwin's rescue, creating a plan to preserve his place in the annals of history. They suggested that Wallace's manuscript and excerpts from Darwin's diaries he jointly presented at the July meeting of the Linnean Society of London, England's premier natural history association. Darwin and Wallace agreed, and their works were read into the record most likely by John Joseph Bennett, secretary of the society. Neither Darwin nor Wallace was present, though, the former because he didn't like to speak in public and the latter because lie was in Indonesia collecting specimens. (It's worth mentioning that Wallace had no say in the matter, consenting to the proposal only after the fact since communication with him in out-of-the-way places took months. Also, because Wallace was poor, and in poor health, it would have been easy for the well-off Darwin and his allies simply to have ignored that fateful letter.)

Oddly enough, the reaction at the meeting was virtually nonexistent. Indeed, in his annual report, Linnean Society president Thomas Bell commented on the lack of important innovations of late. "The year which has passed," he concluded, "has not, indeed, been marked by any of those striking discoveries which at once revolutionize, so to speak, the department of science on which they bear." (2) Nonetheless, Darwin's supporters recognized the significance of his work and urged him to move immediately to publish a full treatise on the topic and thus, the following year, one of the classics of the scientific literature, On the Origins of Species, was born.

Most controversial about the book wasn't evolution; indeed, intellectuals across the disciplines (including his own grandfather, the physician and polymath Erasmus Darwin) had been discussing it for centuries.' What caused the biggest problems within science, religion, and politics, then as today, was the mechanism he described so insightfully. Darwin (and Wallace) envisioned the power of natural selection, the process by which organisms' reproductive rates differ due to varying physiological and behavioral characteristics. Over time, this process shapes a species akin to how animal breeders mold various characteristics of their livestock. In fact, natural selection was important enough to find its way into the full title of his great book: On the Origins of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle fir Life.

Natural selection, at its heart, is a shockingly simple idea. (Biologist Thomas Henry Huxley, Darwin's friend and champion, exclaimed after learning the details, "How extremely stupid not to have thought of that!" and, I'd like to think, slapped his forehead.) Natural selection requires three things, elemental criteria that, it turns out, exist in every population. First, there has to be variability across individuals. In other words, individuals can't be identical in every respect. (That's not to say that some individuals, identical human twins for example, can't exist. Rather, all individuals in a population can't be exactly the same.) Second, the variability has to be heritable. In other words, a genetic basis must underlie some of the variability and differences must be able to pass from parent to offspring. Third, the environment in which organisms live and reproduce has to contain a finite amount of critically important resources. In other words, organisms must be limited in their ability to reproduce because some resources are in short supply.

Put all of this together and you end up with evolution. Some organisms will be better able than others to utilize limited resources (like food, water, shelter, or hiding places from predators) and, thus, be more likely to survive and reproduce. For instance, bacteria can now live comfortably on nylon as a source of food, a synthetic product not in existence until the early 20th century. And the gene for coat color has mutated in some deer mice; the fur of the rodents in the Nebraskan Sand-hills is sandy-colored to make them harder to spot on the grasslands while their woodland relatives are dark brown to protect them in the forest. Because offspring share some parental genes, progenitors pass along traits that lead to their progeny's success; these are the genetic tools to enable the next generation to make the grade. Natural selection is just that basic yet just that profound. Success breeds success and those individuals best able to reproduce will leave more offspring than others. In the natural world, organisms are constantly being tested. Those found wanting will reproduce less frequently and less successfully and their genes will slowly decrease in frequency in the population. Anything an organism can do to maximize its efficiency at turning resources into offspring will be favored. David Barash, an evolutionary psychologist at University of Washington, described the situation both succinctly and poetically: "Evolution is a stern task-mistress, constantly sifting and sorting through alternatives to find the most efficient and fitness enhancing way to accomplish the various tasks of living." (4)

Overcoming resistance

But natural selection wasn't immediately accepted. Scientists such as Sir Richard Owen, the great paleontologist and the first to use the word dinosaur, who had no problem conceiving of a world in which evolution occurred, refused to believe that natural selection could create the diversity of life we see before us. Further, the transfer of natural selection from a potent biological force to a dangerous political ideology began in the 1870s when sociologist and philosopher Herbert Spencer coined the term survival of the fittest as a synonym for natural selection. Although quickly gaining entry into everyday vernacular, survival of the fittest is somewhat misleading because reproduction rather than survival is the key in assessing long-term success. (Survival is only important because the dead can't reproduce!) Survival of the fittest soon morphed into social Darwinism, an equally troubling notion because it oddly assumes that what is biologically natural must always be morally appropriate. Indeed, a wide array of problematic causes used social Darwinism as a warped platform, from eugenics (e.g., sterilizing the mentally handicapped) to libertarianism (e.g., refusing to fund social programs because they help the poor or, as some crassly express it, less fit, survive).

Theologians including Charles Hodge, head of the Princeton Theological Seminary from 1851 to '78, were upset because natural selection apparently removed the need for God to play an active role in creating species or shaping various traits. Biological forces alone could now be seen to account for the variability in the world; thus, it was unnecessary to turn to a higher authority as a direct explanation for the diversity of life. And many looking to build a more just society, like Anglican Bishop Samuel Wilberforce--such an antagonist of Darwin's that he publically debated Huxley, who called himself Darwin's bulldog, to a packed house of hundreds in 1860--were appalled at what they saw as the political implications of natural selection. In essence, they quickly noted and were repelled by the possible consequences of moving Darwin's ideas into the social arena since doing so turned the objective into the subjective, adding an agenda to what should be neutral.

Scientists had good reason to be skeptical. Genes, the unit of heredity that allows natural selection to operate, weren't even defined until 1909 when Danish botanist Wilhelm Johannsen devised the term--decades after Darwin's death in 1882--and until that point it was difficult, perhaps impossible, to operationalize Darwin's theory. It wasn't until the first part of the 20th century that the main pieces of modern evolutionary theory came together in what was to be known as the "modern evolutionary synthesis." At that point enough was known to allow scientists to link natural selection, the new field of genetics, and mutation theory in a way that explained biological patterns across a wide array of species and, via the growing fossil record, the huge expanse of geological time. Evolutionary theory, with natural selection as one of its most important mechanisms, became fully accepted in the scientific community. (And outside it. For example, in 2009, University of Cambridge's Fitzwilliam Museum and the Yale Center for British Art both presented the exhibit "Endless Forms: Charles Darwin, Natural Science and the Visual Arts," which explored the impact Darwin's ideas had on artistic creation.5) Evolutionary theory itself, in a manner of speaking, made the grade.

As scientists came on board, religious leaders followed, recognizing both that empirical knowledge didn't challenge their faith and that leading a devout life didn't mean they had to refute scientific breakthroughs. For instance, many devout individuals such as Charles Kingsley, Church of England minister, professor and author, accommodated evolution by recognizing that God may well have used it as a mechanism for creation. Although the controversy between evolution and creationism still rages in the United States (6) (and simmers in other portions of the world), (7) the majority of Christians around the globe accept modern science and evolutionary theory (as do members of most religions, but the most vocal creationists have typically been Christian). (8) Said another way, science and religion ask different questions and use different methodologies in their search for answers. Thus, they are being graded on different grounds and need not compete with one another.

Those who refuse to accept evolutionary theory on religious grounds tend to raise three objections. First, they assert that evolution can't be scientifically correct because it contradicts scriptural teaching. For example, some interpret Genesis to mean that the universe is only approximately 6,000 years old, but all scientific evidence available points to 13.75 billion years. Second, they contend that natural selection is not a strong enough mechanism to function in the way science claims it does because of their belief that genetic mutations cannot yield positive results for organisms. However, mathematical modeling of the spread of mutations throughout populations, coupled with laboratory and field experiments that track gene flow, have put this criticism to rest for the scientific community. Third, they posit that if natural selection is accepted as an important biological force, then there's an obligation to have a perverse view of human nature because the inevitable upshot of evolution leads to the Holocaust and other situations where morality is trumped by power. (9) (One reason why William Jennings Bryan, a three-time Democratic candidate for the U.S. presidency and a populist working tirelessly for the downtrodden, detested evolution was because he "feared that Darwinism encouraged the exploitation of labor by justifying selfish competition and discouraging reform." (10) This antipathy for natural selection prompted him to agree to serve as lead attorney for the state of Tennessee in its prosecution of John Scopes for teaching human evolution in a Dayton public high school in 1925, facing off against famed criminal attorney Clarence Darrow in the "monkey trial.") But this is a philosophical rather than a biological viewpoint. Biology led to the development of our brains--and to consciousness and self-awareness. We were thus able to construct human societies that permit us to move beyond some biological imperatives. Just because we are part of the animal kingdom does not mean that we have to act in the same manner as other members of that kingdom; we can exercise choice to create a social network not observed in other species. From undertaking philanthropic acts to creating a system of morals and punishing transgressors, we are distinct among other of the world's life forms. We humans make the grade with our heads and our bodies.

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Developing perspective

Perhaps the world's best-known popularizer of evolution, biologist Richard Dawkins, made this point when he said, "No self-respecting person would want to live in a society that operates according to Darwinian laws. I am a passionate Darwinist, when it involves explaining the development of life. However, I am a passionate anti-Darwinist when it involves the kind of society in which we want to live. A Darwinian state would be a Fascist state." (11) Barash came to a similar conclusion that it is inappropriate to think we can derive ethical lessons from evolution: "The harsh reality is that evolution by natural selection is a marvelous thing to learn about, but a terrible one to learn from." (12) Philosopher Daniel Dennett is even more graphic and terse when he called social Darwinism "an odious misapplication of Darwinian thinking in defense of political doctrines that range from callous to heinous." (13)

Science writer Sam Kean summed up the larger picture succinctly when he noted, "What happens in nature is a poor guide for making decisions anyway. One of the biggest boners in ethical philosophy is the naturalistic fallacy, which equates nature with 'what's right,' and uses 'what's natural' to justify or excuse prejudice. We human beings are humane in part because we can look beyond our biology." (14)

Natural selection is the quintessential way in which nature challenges individuals. Make the grade, pass the test, leave offspring carrying your genes. Fail and your descendants never even have the chance to try. Darwin shaped this incredible-and incredibly simple--idea more than 150 years ago. And it still serves us humans well--when applied to a scientific context. But it remains just as meaningless today as it was 150 years ago when misused in a political context.

Michael Zimmerman, Academic Vice President and Provost at The Evergreen State College, is a biologist by training who specializes in plant-animal interactions, particularly those associated with pollination, and in science literacy in general and the evolution-creationism controversy in particular. His publications on these topics include Science, Nonscience, and Nonsense: Approaching Environmental Literacy (The Johns Hopkins University Press, 1995), a blog for The Huffington Post, and op-ed pieces and book reviews for numerous magazines and newspapers. Zimmerman is the founder and executive director of The Clergy Letter Project (www.theclergyletterproject.org), which promotes the teaching of evolution and argues that religion and science are compatible. He is represented by the Ovation Agency, Inc.: Speakers on Issues that Matter (www.ovationagency.com). Zimmerman earned a bachelor's degree in geography from University of Chicago and a doctorate in ecology from Washington University in St. Louis. He earlier held administrative positions at the arts and sciences schools at Butler University, University of Wisconsin Oshkosh, and Oberlin College. Email him at zimmermm@evergreen.edu.

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Author:Zimmerman, Michael
Publication:Phi Kappa Phi Forum
Geographic Code:1USA
Date:Sep 22, 2012
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