Evolution Unites Us All

Protesters in New Mexico

In 2017, New Mexicans crowded into a public hearing to speak up for scientific literacy, and the state Department of Education listened. Citizens criticized the department’s plan to drop climate change, the age of the Earth, and evolution from the science standards. In response to backlash, the DOE dropped its plan to edit the standards. Instead it will follow the Next Generation Science Standards in full, as developed by a consortium of states and organizations, such as the National Science Teachers Association. This news is a welcome change in a world that has increasingly rejected evolution science. Recently, governments from Turkey to Florida have been undermining children’s education in evolution. Our kids deserve a scientific understanding of who we are and where we came from. Evolution is more than just the bedrock of biology. Humans evolved from earlier life forms, and a scientific understanding of that fact promotes self-understanding and justice. From biology, we learn that each of us is born unique, that we are related to all life on Earth, and that we are connected to each other.

The theory of evolution tells us that humans can never fit neatly into categories. Natural selection works because the organisms in a population always vary among themselves. Today we need this lesson especially in the realm of gender diversity. Human brains prefer simple binary thinking, so it’s common for people to consider “male” and “female” to be all there is to say about gender. Obviously, we see more diversity than that, and biology tells us why. Biology is messy. The concepts of “male” and “female” are handy shortcuts, but the messy truth is that all sorts of different developmental processes contribute to that dichotomy, and human populations exhibit variety in all those processes. Generating adult male and female humans requires many steps. The fetuses’ genitals develop, their brains masculinize or feminize, the infants experience life either revved up on testosterone or not, children develop gender identities, and they develop sexual attraction. Finally, puberty hits and hormones activate the hormone-sensitive brain structures that were laid down during fetal development. Humans differ from each other in all those biological processes, most commonly in terms of sexual attraction. If all this built-in gender variety isn’t enough, the brain evolved for behavioral flexibility, so of course humans express more variety than found in our genes and hormones. Opponents of gender diversity treat is as if it were a violation of an ultimate, binary division, but evolution says that variety is our birthright.

Paradoxically, while the theory of evolution affirms that we are each unique, it also tells us how much we have in common with the rest of the living world. Traditionalists say that humans are essentially separate from animals, but evolution says we are in fact animals. When I was working on Grandmother Fish, Eric Meikle of the National Center for Science Education impressed on me that the core message of evolution is, “We are all related.” We need this lesson today because scientists say that we are driving our planet into its sixth global extinction. Sixty-six million years ago, an asteroid wrecked the planet, but today the villains are climate change and habitat destruction. The theory of evolution tells us that the species we wipe out are our flesh and blood. The polar bears and all other living things are literally our distant cousins. Furthermore, just as all living things are one family, all humanity is one human race, as Darwin himself recognized. In fact, the entire Homo sapiens population today is just one closely related branch of the human race, which until recently included the Neanderthals, Denisovans, and more. Evolution science says that those of us on humanity’s one remaining branch are more alike than different.

Evolution tells us that we are related to all people not only by our shared DNA but also by our shared social instincts. Zoologists call a species like us “obligatorily social.” In everyday terms, we need each other. If you think that hell is other people, anyone in solitary confinement can tell you the opposite. For the human animal, sociality comes built in. Our natural habitat is not the savanna but the tribe. Our smile, for example, is an instinctive sign of happiness, and it functions only in a group. Our eyes also have white scleras so one human can see where the other is looking. Other primates have dark scleras so that competitors can’t track their gazes, but we humans are born to work together. According to social psychologists such as Jonathan Haidt, caring for others is a moral imperative that our ancestors evolved long ago. Today when politics is so divisive, maybe the theory of evolution can remind us of the value we all place on the primeval drive to care for each other.

Evolution says we are all unique, all related, and all bound up in each other’s destinies. Let’s take that to heart. Opponents of evolutionary theory are undermining the scientific understanding of human origins, gender diversity, and human nature. In this time of cultural conflict, let’s speak up for science like the people of New Mexico did in 2017. Let’s honor our connections—to our neighbors, to all humanity, and to the entire living world.