The human mouth does not exist to speak English. I have a mouth because it enables me to eat and breathe. Speech, then, merely came along as a mistake. A commonly held understanding in evolutionary biology suggests that this “mistake” took place at the dawn of the anatomically modern human era, likely some 200,000 years ago. The larynx began to develop in a lower position in the throat compared to other primates, and suddenly it was substantially easier to choke on food. Ironically, this same trait is what many scientists believed begot language, a prized invention unique to us, as now we could produce a wide range of distinctive vowels, leading to feats of intellect and culture previously impossible. Among scientists, this idea is known as laryngeal descent theory (LDT).
In Dec. 2019, however, a research paper in Science Advances tramped all over LDT with several findings, the most pointed of which proposes that the necessary throat shape and motor control has existed for the past 27 million years all along — long before humans branched off from baboons and other Old World monkeys. So, perhaps we aren’t so special.
Cognitive scientist Philip Lieberman of Brown University, the central developer of LDT, rebutted the recent paper’s claims that “monkey vocal tracts are speech-ready” and “the evolution of human speech capabilities required neural change rather than modifications of vocal anatomy.” Whether LDT is correct or not, it was, or still is, the dogma; thus, no one bothered to look deeper into the past until recently.
Despite the controversy, I bet there’s a treasure trove of stories about our evolution in those 27 million years. Think about the evolution of humans and what their daily lives were like. Back then, the reasons for certain traits persisting were clearer. Someone with the polygenetic makeup for longer arms could perhaps throw spears farther, thus was likelier to live to reproductive age than someone who did not have that genetic makeup. Today with modern medicine and civilization, people can live and reproduce happily regardless of whether their genes would be “better suited” to the wilderness. But in the words of the prolific English author H.G. Wells, “Man is the unnatural animal, the rebel child of nature, and more and more does he turn himself against the harsh and fitful hand that reared him.” Have innovation and the understanding of our species halted human evolution altogether, or will it continue with the rest of the animal kingdom? Does it matter? If evolution were to come to a halt, that would limit the potential to develop new organs, but unlike other animals, we don’t need to use specific body parts for their original purposes anyway. In fact, our sense of identity comes from abstracting them.
Consider how the sting of a wasp never really goes away or how tough it is to forget your first kiss. It is fairly well established that the functionality of adaptive memory in the brain is to retain and leverage survival- or reproduction-related experiences to make more advantageous decisions down the line. My memory does not exist to remember Maxwell’s equations or to write creative nonfiction about my lived experiences — yet we have, rather aptly, contorted the ability to our advantage.
Often, though, memories follow a curve of exponential decay until the details fade when the horizontal asymptote is approached, and the absence of memory can affect a life as much as the presence of it does. Suddenly, I am compelled to recall American memoirist Patricia Hampl’s essay “Memory and Imagination.” In it, she said, “What is remembered is what becomes reality.” But it is my impression that, as remarkable as the brain is, the difference between fiction and fact when recalling memories over vast expanses of time may eventually become difficult to discern. Simultaneously, the way that we tell these narratives to ourselves helps us make sense of the world and establish a self-concept. Without stories and memory, there would be no identity. But how, exactly, does memory chronicle events?
In “The Order of Time,” theoretical physicist Carlo Rovell proposes that the past, present and future may not be as they seem. Apparently, some fundamental equations of quantum gravity (e.g., Wheeler–DeWitt) can be written without any reference to time at all. Ever since I read “Seven Brief Lessons on Physics,” I have kept wondering whether time is as physical and real as we make it out to be in our memories. In some ways, time could just be a clever device for our minds to interpret the motion of rigid bodies in this universe. So, when Hampl goes on in the essay to say that “our capacity to move forward as developing beings rests on a healthy relation with the past,” I start to think about how, biologically, memory evolved, and afforded us the ability to organize reality and project into the future. As aforementioned, we need the notion of time — it helps us define stories and courses of action. But narratives are funny in that they can fade into the background or emerge into the foreground whenever they want, altering how we behave and the decisions we make. That altered consciousness is how reality changes, as Hampl put it — and that subjective experience is all that can be perceived by a human being at one time, regardless of what is or is not the physical reality. What lies beyond the Phaneron arguably does not matter.
Contact Matthew Turk at mjturk ‘at’ stanford.edu.