THE HISTORY OF PEOPLE, PART 2

 

I started part one of this series of articles asking, “what does it mean to be human,” but didn’t quite get to answering it. In this installment we’ll be following the journey of our own species, Homo sapiens, from a primitive hunter-gather existence to living in complex civilizations. Inherent in this story though is an examination of what it means to be human. I’ll delve more into this at the end of this post, but spoiler alert, it’s complicated.

Most aspects of early Homo sapiens are highly contentious with competing theories having their expert fanboys defending their positions. With that in mind, here’s my best summary of how our species evolved to the point that we can read articles about our evolution on the internet. Until recently it was believed Homo sapiens came into existence only about 150k to 200k years ago, however recent archeological finds have pushed that date back to over 300k years ago, perhaps as much as 400k. Of course, evolution happens gradually over long periods of time which makes dating the beginning of a species problematic. The individuals that existed 300k plus years ago are considered the same species as us, but they weren’t entirely anatomically modern either.

The first anatomically modern Homo sapiens are believed to have existed between 150k and 200k years ago. In other words, if we had a time machine and could snatch a newborn baby from the first Homo sapiens 350k years ago and another from 175k, the older one would be human but also recognizably different from us while the second one could theoretically could fit into modern society. But here’s the really interesting thing, nothing much changed with the emergence of anatomically modern humans. They continued to live a primitive hunter-gather existence without any noticeable advancements for thousands of years.

Most of the evidence for the beginnings of a sustained advancement of the species seems to indicate that real changes in Humanity started around 50k years ago or possibly a little earlier.  Interestingly about the same time Neanderthals went extinct. There’re a couple things to keep in mind here; the first being the last ice age began roughly 100k years ago and lasted up to about 12k years ago. The beginning of the ice age also seems to correspond with the spread of Homo sapiens out of Africa. 

You might be thinking that Africa seems like the perfect place to wait out an ice age since it remained relatively warm. However, it seems that the ice age changed weather patterns and the lower sea levels caused by increasing glaciers meant the globe became increasingly arid. Dryer conditions in Africa likely forced Homo sapiens out of their native Africa in search of better prospects elsewhere. The fossil records reveal that by at least 90k years ago our ancestors were on the move north into Asia and later Europe.

I think it’s hard to overestimate the effect on humanity of this forced movement north, right into the frozen tundra of the ice age. For over 100k years humans had been doing fine in Africa, but the drastic change of environment brought on by ice age and the migration north forced these people to find new ways to adapt and survive. Success was far from assured and Homo sapiens nearly went extinct, perhaps getting down to a few thousand, or maybe even a few hundred individuals.

It was also during this time that Humans first came into contact with Neanderthals. This contact has been the subject of much speculation. Until recently the interaction between the two species was minimized, however advancements in DNA technology has shown there was inter-species mating. Most non-African people have between 1 and 3 percent Neanderthal DNA in their bodies. Despite this there are some experts who continue to argue that humans and Neanderthals were incapable of breeding and among other experts there is great disagreement on the frequency and circumstances of these inter-species hook-ups. 

It’s even within the realm of possibility that these first Homo sapiens to venture north learned technics for survival from the Neanderthals who were native to this region, not unlike the Pilgrims and the Native Americans of the 1600s New England. It’s also possible that like those Native Americans, their initial generosity was rewarded by later being overrun by the newcomers in the struggle over limited resources. Regardless of how it happened, these early migrants to the north learned the skills necessary to survive and eventually thrive in their new frozen environment.

Another factor to consider is the development of advance language skills which seems to have been well established by 50k years ago. This is one of the areas with the most intense academic debate, largely because of the inherent difficulty in proving when spoken language began from archeological evidence. It’s likely that by 200k years ago that humans had the physiological ability to talk, possibly much earlier than that. In fact, some scientists believe the ability to talk dates back to earlier members of the Homo genus, which is of course, yet another area of much debate. 

It’s almost certain that early humans could communicate through gestures and primitive vocal sounds, but at what point did this advance to a complex structured language capable communicating a wide range of ideas, it’s hard to say but it seems likely it was somewhere between 100k and 50k years ago, although some would argue it was earlier.

At first the gap between when the ability to talk and the development of language might seem odd. However, if you’ve ever been around babies, you know language doesn’t just come naturally to people, it takes years of exposure to language before children approach anything near fluency. The length of the gap between when human gained the physical ability to talk and the development of complex language is unknown but it seems likely it was 10s or perhaps 100s of thousands of years. This is speculation, but it seems likely to me that advanced language skills probably date back to around 50k years ago, corresponding with the general rise in human culture and technology that we see happening at that time.

So, after 100k plus years with a relative lack of human cultural progress, pushed on by the challenges of ice age, we start seeing much more recognizable modern human behavior by at least by 50k years ago. Advances in tools, clothing, language, art, and development of rituals and belief systems are all evidence of this trend. This is also the period we see humans expanding into more and more parts of the world. By 35 to 40k years ago modern humans had spread to Australia and Northeast Asia, only the Americas remained unpopulated by Homo sapiens.

Despite all these advances, the first civilizations were still in the future. These people typically lived in relatively small groups of 20 to 30 individuals and survived as hunter-gathers, often following herds during seasonal migrations. This nomadic lifestyle prevented the formation of permanent cities and structures, although they likely returned to familiar areas each season. Humans continued to make advancements in technology and culture throughout this era, but their basic lifestyle remained centered around nomadic hunting and gathering through the end of the Ice Age, roughly 10,000 B.C.  When the earth started to warm at the end of the Ice Age its ability to support a much larger population of humans blossomed leading to the agricultural revolution, the first cities and eventually the first human civilizations.

I’ve followed the evolution of early primates from when they first stood upright and stepped out on the African savannahs roughly seven million years ago up to about 10,000 years ago on the cusp of the first human civilizations. However, I still haven’t answered the question I started the first article in this series with, “what does it mean to be human?” At what point were we human beings, and not just a smarter than average chimpanzee? As I have eluded to before, it’s not a simple question, and scientists, philosophers and others have landed on different answers. 

Complicating this even further is the fact that several of the criteria people have used in the past for defining humanity have come under increasing scrutiny as we continue to increase our scientific understanding of the world. The ability to communicate with language, to consider the past and future, to make logical decisions, to have unique personalities and others attributes have been proven to exists in non-primate animals that most wouldn’t consider to be human, even if they possess intelligence.

Some have recognized the humanity of those first primates to stand upright, but for most they are too far removed from us to be considered humans. More commonly the first primates to be classified by the genus Homo are referred to humans but this still seems a bit of a stretch given the first creatures of this group were still under 5 feet tall and only had brains two-thirds the size of modern humans. I think at this point we can start using the term human like primates, but they weren’t fully human yet. However, beginning around 700,000 years ago we start seeing several species of primates that were both physically and intellectually the equal of our own species. I think at this point you can’t really make a meaningful distinction between them and us, and therefore we should start considering them to be the earliest human beings.

That’s not the final word however because others have concluded that the term “human being” and Homo sapien are interchangeable and therefore wouldn’t include Neanderthals or Homo heidelbergensis as being human. Others have viewed the primitive lifestyles of early Homo sapiens and decided that even though they were anatomically human, that it wasn’t until they mastered spoken language and began creating art around 50,000 years ago that they became human. Of course, there have also always been people that viewed certain groups of people as less than human, such as various groups of indigenous people, slaves or ethnic minorities.

However you view this question, most agree that by 10,000 years ago that Homo sapiens were the only fully human creatures on the planet. Up until that point the impact of humans on the planet hadn’t been that remarkedly different from other animals. But with the convergence of advances in human technology and the end of the last ice age, the planet was about to be transformed in ways never before seen. The rise of human of civilization will be the next article in this series.

NOTE: I originally planned to pick a realistic representation of Stone Age people to accompany this article, however I couldn’t find one. Every painting I found of early Homo sapiens depicted white people; however, in recent years we’ve discovered that white skin is a recent phenomenon. The first Homo sapiens to move into Europe from Africa had dark skin and it’s now believed that continued to be the case throughout the Ice Age. It was only 8 to 10,000 years ago, after people started migrating further north after the glaciers receded from central Europe, that the genetic evidence indicates lighter skin started to develop. In the northern latitudes white skin was an advantage because it absorbs more sun allowing the body to produce more vitamin D, which is essential to life. 

In southern latitudes there was plenty of sun and darker skin provide a measure of protection against excessive amounts of sun. It should also be noted that humans didn’t have the ability to digest diary products until about 4 to 5,000 years ago, so the sun was the primary source of vitamin D. Arguably the poster from the film One Million Years B.C. gets the time frame about right. Homo Sapiens didn’t exist one million years ago but other members of the genus Homo, such as Homo erectus, definitely did. Finally, these early humans were not battling it out with the dinosaurs which went extinct about 65 million years ago. They did co-exist with Mammoths, 10’ tall orangutans, saber-toothed cats, Dire Wolves, and lizards and crocodiles in excess of 20 feet long, which is still pretty cool.