Modern humans, scientifically known as Homo sapiens, have existed for approximately 300,000 years. The earliest fossils and archaeological evidence of anatomically modern humans date back to around 300,000 years ago in Africa. But the history of hominids dates back much further, with various hominid species evolving over millions of years.
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How Long Have Humans Existed? Starting from Homo Sapiens
The obvious answer to the question would seem to lie in simply replacing the word human with Homo sapiens. Evolution may not give us a precise clock, but surely it offers us at least some reasonably solid delineation as to the before and after of when we first branched off the evolutionary tree.
Unfortunately, paleontology is an incomplete and ever-shifting science. The picture painted by the scant fossil record has been redrawn multiple times, and doubtless will again – and even the steady-state of that picture at any given time is more muddled than you might expect.
READ MORE: Early Humans
The Dividing Line
The classic “biological species” concept of a species states that animals comprise different species when they can no longer interbreed. When an organism has become so genetically distinct that it can no longer produce hybrids with related populations, it’s a new species.
Chimpanzees are our closest living relatives. But since we’ve evolved too far from each other to interbreed, Homo sapiens and Pan troglodytes are inarguably distinct species.
The Blurred Line
But this definition has some flaws. Such genetic isolation between two species takes millions of years to complete – humans and chimpanzees diverged over six million years ago – and plenty of creatures not considered the same species are still capable of producing offspring.
Various feline hybrids exist, such as ligers created from lions and tigers. Wolves and the domesticated dogs that were bred from them can still create hybrids as well. Horses and donkeys create mules, and research suggests that almost twenty percent of wild bird species may interbreed.
This makes the origin point of a new species less of a bright line and more of a judgment call. There are currently several schools of thought on the precise demarcation of species based on the distinctiveness of key biological characteristics, genetic similarity, and other methodologies. And with a data set as incomplete and unsettled as the fossil record, that process naturally involves significant debate.
The Old and the New
Ostensibly, Homo sapiens first appeared about 300,000 years ago. But these were not humans as we know them today – referred to as archaic Homo sapiens, these early humans had significant physiological differences that marked them as distinct from us.
It is even argued in some quarters that they comprise their own species – or at least a subspecies – bridging modern humans with our ancestor, Homo heidelbergensis. This provisional species – deemed Homo helmei by some paleontologists – possessed a slightly smaller brain and smaller teeth than modern Homo sapiens, as well as a more prominent brow, thicker skull, wider nasal passages, and almost non-existent chin.
Likewise, another possible Homo sapiens subspecies was found at Herto, Ethiopia, and dates from about 160,000 years ago. This “Herto Man,” classified as Homo sapiens idaltu, marks an even closer progression to modern humans, with only slight morphological differences delineating it as a unique subspecies.
The Extended Family
Modern humans didn’t appear until about the time of Herto man, roughly 160,000 years ago. The various archaic Homo Sapiens subspecies tapered out about 100,000 years ago, when the extraordinary run of our more distant relative Homo erectus also ended, leaving only modern Homo sapiens and Homo neanderthalensis (themselves also descendants of H. heidelbergensis) as Earth’s remaining hominids.
So, our initially simple answer is first complicated by whether we consider both archaic as well as modern Homo sapiens to fall under the umbrella of human. If so, then humans existed as far back as 300,000 years in Africa. If not, our history is only a little more than half that – but in another view, it could also be a lot longer.
The fuzziness of species separation doesn’t only apply when one population descends from another. There are other members of the Homo genus, closely related to us, who should almost certainly be included in our definition of human, and some of their histories extend back much further than that of our species.
Our closest relative, as already noted, was Homo neanderthalensis. They split from the same common ancestor, H. heidelbergensis, as H. sapiens did, the only difference being they evolved in Europe while the fossil record suggests H. sapiens initially evolved in East Africa.
Neanderthal man wasn’t a more primitive, failed offshoot. They developed and used clothing and surprisingly sophisticated tools. They mastered fire and have left evidence of at least rudimentary spiritual practices.
Given all this, Neanderthals – morphological differences notwithstanding – would certainly seem to fall under the umbrella of human. It’s even been posited that H. sapiens and H. neanderthalensis, based on evidence of interbreeding in the human genome, actually both represent subspecies of Homo sapiens – though this is based on that classic species concept and has limited acceptance in broader scientific circles.
While anatomically modern humans appeared 160,000 years ago, the Neanderthals came along earlier – about 400,000 years ago, predating even the archaic H. sapiens. So, while outside our direct evolutionary line, Neanderthals could extend the history of humans back at least an extra 100,000 years.
An even more distant, but perhaps more important, relative is Homo erectus. The predecessor of H. heidelbergensis, who split from them some 700,000 years ago, H. erectus is essentially the grandfather of H. sapiens.
H. erectus existed for a staggeringly long period of time – appearing about 1.8 million years ago (though the first half-million years of that are generally classified as a separate species, H. ergaster, exclusive to Africa). And this ancestor endured well into the time of Homo sapiens.
Homo erectus was the first hominid to display the bodily proportions found in modern humans – they had longer legs, shorter arms, and bore other morphological advancements befitting a species that began to walk upright on two legs rather than simply climb trees to survive.
Whether a Neanderthal would get a second glance on the street if you decked them out with a modern suit and haircut is debatable. There’s no doubt that H. erectus would – yet looking at reconstructions of them, one is struck by the similarities to ourselves, and the label human seems a natural and instinctive fit – and that pushes the start of humankind back almost two million years.
Mind vs. Body
But perhaps when we ask when humans began, we’re not strictly speaking of anatomy or taxonomy. That, as we’ve just established, is a slippery slope of blurred lines, best guesses, and conflicting opinions.
Perhaps what we really mean is “When did humanity begin”? That is when did something recognizable as human culture, as the mental development of human beings as more than animals – even clever animals – truly begin?
When did we become self-aware? When did we start to think?
The oldest recognizable civilization that’s been documented is that of Mesopotamia, which predated that of Ancient Egypt by some 500 years with the rise of the Sumerians about 3500 B.C.E. The written word, in the form of cuneiform, originated from this culture and dates back as far as 4000 B.C.E.
But while Sumer marks the earliest “complete” culture on record, it’s worth taking a moment to realize just how many blank pages that leaves in the journal of humanity. The culture of Ancient Egypt ran for some 2500 years (or 3000, if Ptolemaic Egypt is included) – yet even going by the most conservative start for “humans,” that of the rise of modern H. sapiens about 160 thousand years ago, over fifty Egyptian civilizations could be placed end-to-end between that origin point and the beginnings of culture in Mesopotamia.
And there are tantalizing landmarks in the midst of history that suggest there’s much to find in that supposedly empty space. While we may never be able to fully uncover whatever pre-Mesopotamian cultures may have existed, these clues confirm for us that there is much more to our history than we know.
Chinese Neolithic cultures in the area of the Yellow and Yangtze Rivers were living in settled communities, domesticating animals and producing painted pottery and carved jade as far back as 7000 BCE. The cultures collectively known as the Mound Builders were developing earthworks and engaging in trade in North America as early as 3000 BCE.
The UK’s Stonehenge was also constructed about 3000 BCE, though the site shows evidence of earlier construction going back 5000 years earlier. And Warren Field in Aberdeenshire, Scotland has a lunar calendar that dates from 8000 BCE.
But the most intriguing of these earlier remnants may be the complex known as Göbekli Tepe. Located in southeastern Turkey, the site consisted of more than 20 stone enclosures featuring intricately carved pillars and stylized sculptures. And it all dates from a staggering 9000 BCE – more than twice as old as the pyramids of Egypt and built by a culture about which we know nothing.
The Measure of a Man
We will likely never know when the first settlement was built, when the basic rules of math were discovered for the first time, or when we first replaced gathering with farming and hunting with herding. The first languages – perhaps even writing earlier than cuneiform, if any existed – are likely lost to time.
Without those blatant markers, how can we settle on a fixed point as the beginning of human civilization, and – in this philosophical sense – the beginning of humans? Well, we can examine a few very basic milestones found in paleoanthropology to help us find what we can call our societal starting point, the origin of our identity as human beings.
The beginnings of mental development show up in tool use, of course. The use of stone (and bone) hammers, scrapers, and even weapons could be said to mark the start of that journey. By that metric, the beginnings of humanity go all the way back to Homo habilis, who was crafting and using sharpened stone tools referred to today as Oldowan tools some 2.6 million years ago.
READ MORE: The Ancient Weapons of Old Civilizations
But tool use isn’t unique to humans. A number of animal species today, from our relatives among the great apes to sea otters and a number of bird species, have been documented using simple, improvised tools – and passing down the knowledge of using them to their offspring. And while these tools are in most cases less sophisticated than even those of H. habilis, they demonstrate that such problem-solving isn’t a unique feature of humanity.
We could also consider evidence of spiritual practice, however simple, as the sign of this ascendance. Certainly, both early Homo sapiens and Neanderthals left evidence of such practices in both burials and cave paintings, though little solid evidence has survived of either ceremonies or funereal practices among earlier hominids.
Again, however, such things are not exclusive to humans. Elephants, famously, seem to engage in funeral practices, as do chimpanzees. Even some bird species, notably crows, seem to engage in ritual behaviors when it comes to death.
There is, however, one trait utterly unique to humans, at least so far – we control fire. There are select species that take advantage of fire – deer that head to burned areas to dine on the new green growth that springs up, for example. There are even (unconfirmed) anecdotal accounts of black kites, a type of Australian raptor, carrying burning sticks from wildfires and dropping them in a new location in order to start additional fires to flush out potential prey.
Only humans can create fire, however. There is no better symbol for learning to master and shape one’s own environment, and this may finally give us our bright line to denote when pre-human became human.
Homo sapiens mastered fire, as did their cousins the Neanderthals. So did their predecessor H. heidelbergensis. But the first human ancestors we truly know to have created and used fire, some 1.5 million years ago, were Homo erectus.
How Long Have Humans Existed? The Starting Line
So it is, then – in anatomy, in tool use, and in the mastery of fire (and in consequence, at least beginning to no longer be at the mercy of nature), Homo erectus stands out as the first hominid to check all the boxes of what we would call human. Long before the first cities, the first written language, the first crops, H. erectus took the first fumbling steps to rise above a purely reactive, bestial existence and begin growing into something greater.
Our written history may only extend back a matter of millennia. Our most ancient great works may have been made in only the last fraction of our time on Earth, but humans, in every way that matters have existed for almost two million years.