Natural Selection: Constantly Testing

Article excerpt

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. …