At root, human evolutionary theory consists of two propositions: (1) that the human species is descended from other similar species and (2) that natural selection has been the primary agency of biological adaptation. Pretty much everything else is subject to some degree of contestation. To conclude this chapter, let us call attention to some of the major corrections we would like to apply to popular misunderstandings of human micro- and macroevolution.
- There is no separation of culture from science, or facts from values, in human evolution.
As we have seen, the scientific study of who we are and where we come from is not biology. It is a branch of anthropology that overlaps in crucial ways with biology, and yet it also traffics in the world of politics, cultures, moral codes, and histories. This is not to say that other sciences can necessarily be free of culture but simply that it is easier to be objective about boron than about your ancestors. Narratives about ancestors are invariably sacred stories, and biological anthropologists incur an unusual responsibility in being the scientific custodians of our ancestors’ stories-writing and validating their stories, shepherding them through history.
- Equality is not identity.
The great geneticist Theodosius Dobzhansky emphasized the distinction between equality (a political state) and identity (a biological state). Sameness/difference is unrelated to equal/unequal, under our system of government. No matter what kind of person you are, you are entitled to equality. Consequently all discussions of race or sex are irrelevant to questions of rights: All citizens are entitled to equal rights. The difficulty is how to guarantee that all receive them, which is a political issue, because obviously there is a great deal of inequality in America. Patterns of social inequality are not grounded in human biological variation. It has become a moral challenge for the nation and for science to better understand this fact, particularly as critiques of equality are too often accompanied by pseudo-biological arguments.
- All humans are equally close to apes, despite the attempt of some people to question the essential humanity of certain populations by suggesting that some people are more apelike than others.
The suggestion that some groups of humans are more naturally apelike than others is a recurrent slander of the modern age. Apelike is obviously a synonym for subhuman; and the symbolic association of apes with African peoples is actually a pre-Darwinian slur, from centuries before evolutionary theory was developed. All humans are equally distantly related from the chimpanzee, but some humans, especially people of color, have been symbolically dehumanized throughout modern history by associating them with apes. Consequently, such a comparison is no longer considered funny.
- Competition can take many forms other than overt aggression.
Some biologists use Darwinism as a way of rationalizing war, arguing that even though war sucks, it is the very competition among political entities that leads to social advances in human history. But even Darwin knew that it wasn’t necessarily the case, and it remains a problematic moral position. Darwin’s intellectual inspiration here was actually the Scottish economist Adam Smith, whose 1776 book The Wealth of Nations is the foundation of modern capitalism. Smith argued that people simply acting in their own best interests in competition with one another would naturally form complex thriving economic systems, which would function to the mutual prosperity of all, as if guided by an “invisible hand.” The competition was neither cutthroat nor physical. Today we recognize competition as potentially occurring in many ways and between several different kinds of things, from DNA segments to cultural artifacts. Physical aggression is one way humans have interacted competitively, but there is nothing particularly Darwinian in the attempt to identify merit in war. A conscientious scientist is more interested in ways to avert it.
- There is no “person of the future.”
We do the great bulk of our adapting culturally, although our gene pool is continually being tweaked by diseases and demographic trends. But of course we cannot predict future environments for our descendants to adapt to, culturally or naturally. The idea that our species is simply a way station for the next great step in evolution betrays teleological thinking about history—that is, the idea that history is preset and that there is a path down which we are proceeding. But there is no path; there is only the present and possible solutions to the problems of the present. Consequently, there is no way to know what a “person of the future” might look like. No lateral toes? Maybe. No wisdom teeth? Maybe. A brain the size of a basketball? Not without radically restructuring the maternal anatomy and the birth process. Perhaps with the colonization of other planets, our own species will undergo novel forms of selection and a great deal of founder effect or genetic drift. But their products are inherently unpredictable.
- Evolution is more like a tree than like an escalator.
Darwin thought of evolution as producing separate branches, like those of a tree, with the tips representing living species. But the word evolution implies to many people an unfolding, a development along a path—this is what the word meant initially to Darwin, who avoided it in the first edition of The Origin of Species. Teleological theories of evolution have indeed been proposed from time to time, but if we see evolution as divergence rather than improvement, then we reject teleology. When creationists ask, “If we evolved from monkeys, then why are there still monkeys?” they are imagining evolution as a teleological process. The pre-Darwinian evolutionist Lamarck imagined that in the face of extinction a species could survive by changing into something a little higher up on the Great Chain of Being. In such a world, monkeys might constantly be evolving into people, but that is not a branching, Darwinian world. Rather, we would say that our monkey ancestor diverged and eventually became an ape-like creature but did so without necessarily exterminating monkeys in the process. Interestingly, genomics is now revealing that speciation is commonly less complete than we used to imagine, and ostensibly discrete branches sometimes come together. This might call for a new metaphor to describe human evolution, such as the roots of a tree, rather than its branches.
- Bible scholarship does not conflict with science.
Contemporary scholars recognize that the Bible is a collection of traditional stories and tales, culled from a larger set of writings from various times and places and later collected into a single volume. They have meant, and continue to mean, different things to different communities. For many centuries, scholars have studied what the texts mean, assuming that the Bible’s meanings are neither obvious nor literal but relevant to the lives of worshippers in any specific time and place and denomination. Consequently, there can be no “true meaning” of the Bible, only the most useful and appropriate meaning for the particular community. Biblical literalism is a very recent phenomenon, independent of the centuries-old humanistic traditions of biblical scholarship, and it demands a very selective and arbitrary approach to the texts chosen to be taken literally. The creationist today thus rejects not merely modern scientific scholarship but modern biblical scholarship as well. Nevertheless, many Jewish, Catholic, and Protestant scholars, as well as scholars from other religious traditions in the modern age, are actively engaged in understanding what it means to lead a fulfilled life in a post-Darwinian world.
Now that you’ve finished this chapter on evolution, you are equipped to go into the post-Darwinian world armed with an understanding of the true intentions of Darwin’s work, and where his findings part from past and current racist misinterpretations of his theories. You understand that politics is often inseparable from biology, no matter the best intentions toward objectivity of the scientist.
Review Questions
- How is the study of your ancestors biopolitical, not just biological? Does that make it less scientific or differently scientific?
- What was gained by reducing organisms to genotypes and species to gene pools? What is gained by reintroducing bodies and species into evolutionary studies?
- The molecular biologist François Jacob argued that evolution is more like a tinkerer than like an engineer. In what ways do we seem like precisely engineered machinery, and in what ways do we seem like jerry-rigged or improvised contraptions?
