Evolution is a hotly debated topic in the United States—particularly the South which is often, though perhaps unfairly, characterized as a region of ignorant sharecroppers who cling to religion instead of reason, faith instead of empiricism. Evolution is so controversial not because of the lack of evidence in support, but because this evidence is seemingly in direct contradiction to the creation story found in in the Bible. According to The Bible, God spoke “let there be light” and there was light. Afterwards he created the heavens and the Earth and all of the creatures who inhabit it, taking a seventh final day to rest. In common conversation, evolution is often coupled with the theory of the Big Bang—a cosmic implosion resulting in scattering of matter yielding the universe. Evolution is actually not concerned with theories of origins of the universe, but many religious practitioners (not just Christians by the way) take umbridge to the notion that evolution created Man instead of some divine creator. However, the debate is more complicated than a simple disagreement over semantics—it’s cultural too.
I have lived the entirety of my short 23 years of life in Alabama. I was raised in a southern Baptist church, and I still identify very much as a Christian. I graduated from the #1 High School in America (as ranked by Newsweek), yet my science teachers refused to teach evolution. I remained skeptical of evolution until my sophomore year of college. So when I say that I am in a unique position to offer insight on the issue of acceptance of evolution in the United States, you will agree.
In the following discussion, I would like to provide 1) a definition of what Evolution is and what it is not, 2) some insight into why the issue is so hotly debated, and 3) possible solutions for bridging the culture chasm between acceptance and refutation of the Theory of Evolution.
First and foremost, the concept of evolution is too often misconstrued as some sort of hocus pocus dreamed up by scientists in order to propagate some sort of New World Order secularist utopia. Evolution is not witchcraft, however, and the meaning of the word is actually quite boring. The word evolution simply means “a change in the frequency of specific genes over time.” This change has no direction—as in to a “better” or “worse” state; but we often use the term (whether accurately or not) to connote a metamorphosis from a less-sophisticated to a more complex state of being or function. Evolution is often associated with the writings of Charles Darwin on his voyage to the Galapagos Islands off the coast of Ecuador; however other scholars, such as Lamarck and Linnaeus, offer significant critiques and expansions upon his model.
Contemporary understanding of evolution supposes that there are four driving forces behind evolution: mutation, natural selection, gene flow, genetic drift.
Mutation is a common-enough concept in public understanding thanks to children’s T.V.
shows and comics such as “X-Men,” and “Teenage Mutant Ninja Turtles.” In the latter, a radioactive ooze seeps into the sewers and transforms four turtles and a rat into anthropomorphic crime-fighters. The former is a little more grounded in pseudo-science, however. Individuals are born with a mutated gene or gene granting them super-powers. In actuality, mutation is simply a copying error in the genetic code. Mutation only becomes evolution when it is inherited. For example, a particular type of butterfly could be born red 99.99% of the time. This is due to a specific genetic string of amino acids related to color outcome. Mutation occurs when one of these amino acids is coded incorrectly, resulting in a different color (phenotype) butterfly. Assuming the butterfly lives to reproduce, its offspring will have a chance to inherit the different color as well—depending on whether or not it is a dominant or recessive trait.
Natural selection is when one trait is particularly favorable in a given environment, causing it to be “selected” for over traits. These traits can be behavioral or phenotypic (appearance)—or both. A classic example within anthropology and evolutionary biology is the peppered moth example from London during the Industrial Revolution. Originally, the peppered moth population was predominately white in color with little black specks dotting their wings. There were, however, some predominately black colored moths too.
The white moths outnumbered the black moths due to their ability to blend into the
background of light colored and lichen-covered trees. This effectively camouflaged the white moths from predators such as birds. However, as a result from increased industrialization pollution soon killed off the lichen and turned the trees black from soot. Now, the black moths were more competitive in the environment and the black colored moth phenotype was naturally selected to continue in the gene pool. The main point of natural selection and fitness is that advantageous traits that lead to successful reproduction and birth of offspring are the ones which will continue to circulate in the gene pool.
The term survival of the fittest gets thrown around too often in discussions of evolution. This phrase does not mean that the strongest or toughest organism will necessarily survive. Some situations and environments actually select for a more docile behavioral strategy, for example. Evolution is primarily concerned with successful procreation of offspring and transfer of inheritable traits. Boiling the concept down even further (because it’s that important!)…
Traits such as ability to attract mates, collect food, and care for offspring all vary in terms of effectiveness. Organisms that possess the more advantageous traits (such as big bright feathers to attract mates, or long beaks to dig into holes in trees to gather grubs) have an increased chance to attract a mate and successfully birth healthy offspring. These offspring have increased chances at carrying the same traits (big feathers, long beaks, etc.) which will in turn provide increased chances for reproduction. Eventually, the majority of the population will possess the traits as those who did not originally will have fewer offspring living to the age of reproduction. Natural selection decreases variation within populations (because the best traits will be the most common).
That was long, but the concept is important to comprehend moving forward in the discussion…
Genetic drift affects the genetic makeup of a population, too, but unlike natural selection it is completely RANDOM. In each generation, some lucky individuals will simply leave behind more offspring (and genes) than other individuals leading to an increase in certain allele frequencies despite fitness for a particular environment or niche. One example could be a natural disaster wiping out parts of a forest. Some organisms will die taking their genes with them, while other organisms of the same species will live to repopulate the species with their own genes.
Gene flow refers to the migration of genes between populations. One example is wind blowing pollen from one region to another. Gene flow increases genetic variation WITHIN populations (because it brings in new genes), and decreases genetic variation BETWEEN populations (because it makes populations more genetically alike).
Those are the four forces of evolution. Refer to this last section as needed.
One talking point among so-called “Creationist” (I hate that term by the way, rather pejorative–instead, let’s call adherents to this school of thought simply anti-evolutionists) is that we cannot observe the transformation (evolution) from one species to another. This is usually grounded in the incorrect assertion that man evolved from “monkeys.” There are so many things wrong such a statement that analyzing it would be too much of a digression.
Micro evolution refers to the varying frequency of certain genotypes, very small changes in alleles over time which may, sometimes, lead to speciation—or the genesis of a new reproductively isolated species, or macro evolution (one species into a different species). Let us be absolutely clear, that this transformation occurs over hundreds of thousands—even millions!—of years. Speciation does not occur in one generation, or two, or even 10. It is a slow, gradual process which usually has many branches—i.e. it is not unilinear.
For example (and perhaps someone can critique the following as I am not as familiar with the subtleties of primate evolution as I would like to be), many anti-evolutionists refute that man and ape are related. According to the Bible, man has dominion over animal and the two are necessarily separate since the creation of Earth. In actuality, man and ape (and monkey) are very closely related and we have several fossils as evidence. Man and ape/monkey branched off from one another several millions of years ago (we will discuss the time-scale of the Earth later) into several different branches including hominids (Australopithecus, Neanderthalensis, and homo, for example), apes, and Old World and New World monkeys. Anti-evolutionists are all too correct in saying that man did not evolve from monkeys. The evolution of hominoids was not unilinear (i.e. one species begat another which begat another), it was multilinear.
Actually, perhaps multilinear is incorrect too. Rather, the line fractured off into several different directions. Image a crack in a piece of class, its lines radiate outward and give birth to new lines over time. It is not my intention to delve to deeply into hominid evolution in this post, so I will sum up the important facts.
1) Speciation occurs over long periods of time.
2) Man and apes/monkeys are closely related-genetically.
3) The evolution of man was not linear; rather there were several diverging paths. Some species survived and others did not. Homo sapiens is the most recent hominid.
4) Yes, there are gaps in the evolution of mankind, but we understand more and more about the hominid line each year. We could delve into a discussion of lumping versus splitting, but I will save that for another post.
I welcome a colleague to provide a more in-depth discussion of hominid evolution with specific emphasis on the split of man and ape/monkey. Until then here are two great websites that provide interactive multi-media explanations: Smithsonian and Becoming Human
Now I will provide an overview of the main points of this post (TL; DR). These are the bare basics we need to establish before moving ahead in the discussion of the politics of evolution in America.
1) Some people’s conceptions of evolution differ.
2) Science defines evolution as a change over time, and anti-evolutionists usually connote evolution with the direct transition from “monkeys” such as chimpanzees (which are actually apes!) to man (Homo sapiens).
3) There are four forces of evolution: Mutation, Natural Selection, Genetic Drift, and Gene Flow.
4) Man and ape/monkey are genetically related, and the genetic lines fractured several millions of years ago in to many different directions. Some of the paths lead to extinction, some to further evolution.
The next post will argue that positions on the Theory of Evolution are not simply differences in opinion or science versus faith—they are deeply rooted in politics and culture.