Evolving Humanism in Light of Genetic Ambiguities

Darwin’s conceptualization of the tree of life (which developed into the phylogenetic trees biologists use today) often seems to present evolution as smooth lines and transitioning branches that trace the clear lineages of our planet’s diverse species. However, the course of evolution is rarely so straightforward. Perhaps nowhere else do we find such startling ambiguities than in the changes undergone by our own species to bring us to our current, modern iteration of Homo sapiens. For instance, at one point in time we were just one of many Homo species, though the others have since died off. But new DNA evidence suggests that some of the other Homo species may live on in modern humans.

A recent article published in the journal Nature reports that humans interbred with Neanderthals 100,000 years ago—much earlier than previously thought. Scientists have known for many years that Homo sapiens and Neanderthals (Homo neanderthalensis) interbred and produced viable offspring. After sequencing the Neanderthal genome, scientists discovered that 1-4 percent of Neanderthal DNA is still present in modern, non-African humans. While this amount of DNA is small and researchers still don’t know the full effects, if any, it may have on our present day lives, scientists do suspect that it may have evolutionary benefits, such as stronger immune systems, as well as potentially negative consequences, such as a propensity for depression or type 2 diabetes. These findings shed light on both strengths and maladies of modern humans, and they also present fascinating revelations about our history.

This discovery that humans had intermingled with Neanderthals 50,000 years earlier than previously believed also indicates that Homo sapiens traveled out of Africa 35,000 years earlier than formerly thought. Yahoo News quoted Sergi Castellano, co-leader of the Nature study, as saying, “It is the first genetic evidence of modern humans outside Africa.” Scientists suspect that instead of one mass migration out of Africa, these humans likely traveled out of Africa earlier and that another group of humans left much later. This information has potentially profound implications for our understanding of how human beings came to dominate every continent on the planet, as well as how we evolved as we spread across the globe.

The information that humans and Neanderthals interbred also raises philosophical questions like, “What is a human? What does it mean to be human?” Scientifically, one might assume that modern humans are their genetics—we are the genes that make us uniquely Homo sapiens. After all, each species has its own special genetic code that differentiates it from all other species on the planet. Hypothetically, it sounds like a simple and easy distinction to make, much like how our phylogenetic tree diagrams seem to demarcate clear borders between species’ evolution. However, if the evidence suggests our genetic codes consist of what was once thought to be a separate species, then the lines between what is human and nonhuman may start to seem blurry. Evolution, rather than clearly delineating one species from another, actually demonstrates that the boundaries between where one species ends and another begins are not so clear.

So what does this information mean for humanism? The humanist worldview is rooted in a framework that places the greater good of humanity, not dogmas passed down from a deity, as central to our understanding of ethics. What happens when our concept of “humanity” is challenged? Some humanists embrace the ambiguity of humanity and describe how our technological advancements are blurring the lines between what is human and what is machine. This view, often referred to as transhumanism, foresees a future in which technology so radically changes us that we become something more than we currently are. Other humanists, however, are wary of these changes and point out that technological advancement is not inherently good unless we as a society employ technology for positive, progressive ends.

Other philosophers like feminist Donna Haraway have advocated for a posthumanist or “cyborg” view of humanity that breaks down oppositions that our culture has traditionally made between human/animal and human/machine. Arguing that evolution and technological advancement have broken down the once clear-cut idea of “human,” the posthumanist view promotes a fluid and ambiguous concept of identity that doesn’t depend on the essentialist conception of “human.” Posthumanism also describes how the concept of “human,” which defines itself just as much by what it is not—it is not animal, it is not machine—has been used to deny full humanity to marginalized groups, including women, LGBTQ individuals, and people of color.

Many humanists would likely respond that while Enlightenment humanism was too myopic in defining “humanity” by its own white, heterosexual, male, property-owning biases, the humanist movement has since evolved beyond those preconceptions. The humanist movement has been at the forefront of movements for equality and justice, from supporting anti-racism to rallying for marriage equality and reproductive rights. While humanism is based on a concept of humanity, our definitions of what humanity includes are constantly evolving. Much like the fuzziness of the tree of life, in which species’ categories must always be questioned and reclassified in light of new scientific evidence and debate, humanism is constantly rethinking its principles to better understand its own ethics and ideas.

The religious right, which bases its morality on rigid absolutes including its understanding of humans as divinely created in the image of God, sees humanism’s flexibility as a fault. However, adapting to new evidence and being willing to ask questions and always seek new answers is humanism’s greatest strength. Humanists see our understanding of knowledge and even of ourselves as a species as a constant process that must change in light of new evidence. Rather than fearing the ambiguities of our evolution, both biologically and philosophically, we embrace them as opportunities to better understand our world and our place in it.