In all of taxonomy, the most “wonder-full” species in Kingdom Animalia is man. The planet has been immutably transformed since our arrival, and our future is full of possibilities. If you consider just 3 generations back, it’s astounding what man has wrought. From the days of a primitive telegraph, behold an infinite world of ones and zeroes echoing throughout cyber space. When our homes were once lighted only by candles, observe (from the International Space Station) our atmosphere glows at night from a miasma of harnessed electricity. Our space gadgets are successfully exploring deep space. We have created life! We have not only adapted to change. . . we have shaped it. Scientists say we have evolved. From a time when all simple life was found in the ocean, we split off and became masters of the planet. If indeed our ancestor was once a fish, then we must continue to evolve. That begs the question, what will man be like two centuries from now?
It’s imperious for us to speculate about our future when we can’t even definitively say where we came from.” To seek that answer, we must ask when man actually become man as we know him? The consensus by historians is that our species is about a million years old, so we must go back considerably further than 3 generations. Assuming 20 years represents a generation, 250 generations takes us back to prehistory—the time before writing was invented. Going back another 250 generations would be about when cultivation of crops came on the scene (10,000 years ago). This leaves 49,500 generations of mankind, or 990,000 years, yet to examine! Fact is, more than 99% of man’s story is hidden in prehistory. Clearly, this makes finding the truth difficult.
Taxonomy categorizes modern humans as from the species Homo sapiens (“wise man” in Latin). Ours is the only surviving species of the entire genus Homo. We are the newest and latest model, the current flag bearer. The predominant view is that we are derived from African great apes. . .but this remains a matter of significant debate (Charles Darwin’s On the Origin of Species remained the most commonly banned science book in 2021). In fact, Darwin never claimed man evolved from apes as some of his detractors said he had. Today this view is rooted in circumstantial evidence only. Theoretically of course, there could exist out there the specific extinct common ancestor as the “missing link” between humans and the great apes—but we have yet to find it. Our current investigative dilemma is one of ancient hit-and-miss fossils and the science of genetics—and a huge spread of time without written records. Because our family tree is really more of a family bush, we may never fully identify the chronological series of species leading to Homo sapiens. Bottom line: we don’t know what we don’t know.
Historically, two models have been advanced to make the case for evolution of Homo sapiens. One says that we came from different locations over a long period, and that these populations eventually interbred, leading to the single species we see today. The other maintains we all started in Africa, and then migrated across the world, also eventually interbreeding. The ‘Out of Africa’ model is currently the most widely accepted. Here’s why:
Even today there’s more genetic diversity in Africa than in the rest of the world put together. Modern DNA is found in a part of our cells known as the mitochondria. Our mitochondrial DNA comes solely from our mother because the female egg contains most of it; the male sperm, not so much. So, your
mitochondrial DNA is almost exactly the same as your mother’s and her mother’s. Here’s the deal: the origin of mitochondrial DNA has been genetically traced by evolutionary biologists back to just one African woman who lived between 50,000 and 500,000 years ago! Now, understand she wasn’t the only woman on earth at the time but scientists think an evolutionary “bottleneck” had killed off most of our species, leaving this African female (AKA “Mitochondrial Eve”) as one of the few survivors to pass along her mitochondrial DNA to so many generations. Genetically, the six billion people of today’s world vary only slightly from those earlier Homo sapiens that ventured out of Africa.
There is abundant fossil evidence that we were preceded for millions of years by other hominins. They all have near unpronounceable names like Ardipithecus, Australopithecus, etc., so most of us flesh-and-blood humans today have difficulty identifying with any of them. They all sort of took their place in the evolutionary spotlight during their window of time only to be replaced by newer, more efficient versions. Homo erectus, thought to have lived 1.7 million years ago, gradually migrated into Asia and parts of Europe. There was, however, at least one other species of Homo who lived contemporaneously with some of these other models, and that was Homo neanderthalensis—the Neanderthals. These hairy, thick-browed hunchbacks were brought to life for most of us through modern popular car insurance ads. The Neanderthals roamed western Asia and Europe some 200,000 years ago and are thought to have been outcompeted by Homo sapiens, who arrived from Africa 150,000 years ago. Less is known about another population of early humans living in Asia at the time—the Denosovans—but research shows them to be distantly related to Neanderthals.
What are the odds these species interbred? Do bears poop in the woods?! Nowadays, many of us carry a small fraction of DNA from our archaic Neanderthal and Denisovan ancestors. Interbreeding generally is bad for genetic fitness of a species because it increases susceptibility to disease and illness. This could explain why Neanderthals became extinct. Scientists have found 9 Neanderthal genes in living humans known to be associated with susceptibility to conditions such as type 2 diabetes, lupus and Chron’s disease. It’s also been shown that high-altitude adaptation in Tibetans may be a consequence of an archaic Denisovan DNA sequence in a region of DNA associated with hemoglobin concentration at high altitudes.
Despite the myth, Neanderthals were pretty bright folks: they hunted, fished, and made their own stone tools. They even created cave paintings, decorated their bodies with jewels and paint, and performed burial ceremonies. The Ice Age ended 11,700 years ago and ushered in the New Stone Age (Neolithic
Period)—a time when Homo sapiens really blossomed. We might have continued our life of hunting, savagery and brutishness right through to today, were it not for one thing: language. We lived in populated villages, began farming, domesticated animals, created commerce, money, mathematics, and writing. Aptly, this was considered the beginning of written history, when events could be recorded for future generations. These tremendous changes in human lifestyle are collectively known as the Neolithic Revolution. It would become the first of many momentous revolutions in mankind’s history!
As humans colonized and settled down all over the world, they differentiated themselves into distinct groups called races. This meant differences appeared in skin color, facial features, hair types and body shape. That said, the concept of race has little meaning at the genetic level. Genetically all these
differences are superficial and based only on a small number of genes that affect external features. In other words, there are no significant differences among races, even though culture wars and tribalism run rampant in human society all these many years later. We’re all humans and, despite what MSNBC and Fox News might say, we have more in common than we have differences. Like it or not, we are all genetic cousins of varying degrees.
Where will evolution take us in the future? In the coming two centuries, is it probable we will learn to engineer and manufacture life to our own specifications? Will we be able to create beings that combine organic and inorganic components, like brain-computer interfaces? We already have found ways to move mechanical parts using electric signals from human nerves. Do you think it’s a leap to imagine the
marrying of machine learning and artificial intelligence to create completely inorganic beings? Will the main products of our future economy be bodies, brains, and minds? As we discover more about our reality, will man achieve God-like stature or descend into insignificance, becoming yet another vanishing species, a speck of DNA in the vastness of evolution?
As provocative as this line of questioning might be, the evolutionary journey from past to present has been nothing short of astounding—even if you won’t accept the science. At some divergent point for life in that once abundant global sea, all of us were born of a mother, connected physically by an umbilical cord, just as she was connected to her mother. Back and forth the cord goes, to the origin of our species. Oh, but if we could only acknowledge that cord—because it’s still there, connecting to all who pass through life with us. Behold your family walking by!
By Larry Gfeller