Evolution is still the best explanation

Feb. 12 marked the 200th birthday of Charles Darwin, the father of evolution, perhaps the greatest idea in the history of science. The concept that all forms of life share a common ancestor is the central and unifying tenet for all of the life sciences. Initially controversial even among the leading scientists of his day, by the end of Darwin’s life, evolution gained the general consensus of the scientific community. But now, even after recent advances in molecular biology have confirmed much of the hard genetic evidence for evolution, Darwin’s idea is still met with resistance in the U.S., accepted by fewer than half of all Americans. Most of the dissent is not purely religious, but partially the result of a fundamental misunderstanding of evolution. First, let’s debunk some common misconceptions: “There is a lack of enough transitional fossils intermediate between ancestral and evolved forms to support evolution.” There is a substantial number of transitional fossils: Archaeopteryx, a dinosaur-bird intermediate is a classic example. Between the modern horse and Hyracotherium over 50 million years ago, there are over a dozen different transitional fossils. But for the “gaps” in the fossil record, evolution has an explanation. Punctuated equilibrium explains that most speciation events occur extremely rapidly over a short period of time and that species do not change considerably after divergence. In fact, speciation has occurred in as few as 15 generations. “While microevolution, changes in the gene pool of a population, has been directly observed, macroevolution, or speciation, has not.” First of all, speciation has been directly observed at least several dozen times in the last hundred years in bacteria, plants and animals. Second, biologists do not consider microevolution and macroevolution to have separate mechanisms for speciation; the mechanisms that create changes in the genetic makeup of a population (microevolution) are the same ones that create speciation (macroevolution). “Evolution is just a theory, not a fact. It has not been proven.” In the layman’s sense, a theory is a doubtful or unproven statement. However, in science, a theory is a hypothesis that has undergone scrutiny and the tests of time and evidence. Alongside general relativity and the law of gravitation, evolution is one of the most established and well-supported theories in science. This year alone, there have already been over 200,000 scientific articles citing the word “evolution.” Over the past two centuries, a substantial body of evidence encompassing diverse elements from anatomical to genetic and molecular evidence has suggested nothing short of “descent with modification.” But even in the common sense of the word “fact,” some scientists have taken it one step further: the National Academy of Science argues that “scientists can also use fact to mean something that has been tested or observed so many times that there is no longer a compelling reason to keep testing or looking for examples. The occurrence of evolution in this sense is fact. Scientists no longer question whether descent with modification occurred because the evidence is so strong.” Nevertheless, regardless of whether one accepts evolution, there is no denying that it is the best scientific explanation of the diversity of life on earth. But then the question arises–why shouldn’t students learn about “alternative hypotheses” and practice “critical thinking” in evaluating scientific evidence? It is true that there is a tiny minority of biologists and earth scientists (less than two-tenths of a percent, according to Newsweek) who still support creationism. However, the scientific support and evidence for creationism is so scarce that teaching it would be not much different from treating alchemy as an “alternative theory” to modern bonding theory. One of the largest databases of research articles, PubMed contains over 17 million articles from reputable journals since 1950. To date, there has not been a single peer-reviewed article that opposes evolution. The purpose of science class, at least in our secular system, is to provide the best, most established explanation. Evolution is clearly that explanation. “Creation science,” the National Academy of Sciences declared, “is in fact not science and should not be presented as such…the claims of creation science lack empirical support and cannot be meaningfully tested.” Luckily, the courts agree: in Edwards v. Aguillard (1987), the Supreme Court ruled that teaching creation science in schools was unconstitutional since it has a “preeminent religious purpose.” More recently disguised as the secular “intelligent design,” creationism has once more been shot down: a federal court ruled in Kitzmiller v. Dover Area School District (2005) that intelligent design was not science and could not “uncouple itself from its creationist, and thus religious, antecedents.” Nevertheless, this hasn’t stopped creationists from adopting yet another guise. Just last June, Louisiana Gov. Bobby Jindal signed the Louisiana Science Education Act, a law that will require “critical thinking” on topics such as “biological evolution, the chemical origins of life, global warming, and human cloning”–topics that just happen to have significant religious opposition to the general scientific consensus. It will be the responsibility of us, as citizens of free religion and thought, to further scientific literacy, fight for the most accurate education, and keep religious ideology out of the public classroom. Nothing short of that would be a suitable honor for Darwin.