Key physical and cultural milestones in modern human evolution, including genetic divergence of ethnic groups. Image credit: Nick Longrich / author provided Posted on 10/29/2020 8:24:40 PM PDT by LibWhacker
When did something like us first appear on the planet? It turns out there’s remarkably little agreement on this question. Fossils and DNA suggest people looking like us, anatomically modern Homo sapiens, evolved around 300,000 years ago. Surprisingly, archaeology—tools, artifacts, cave art—suggest that complex technology and cultures, “behavioral modernity,” evolved more recently: 50,000 to 65,000 years ago.
Some scientists interpret this as suggesting the earliest Homo sapiens weren’t entirely modern. Yet the different data tracks different things. Skulls and genes tell us about brains, artifacts about culture. Our brains probably became modern before our cultures.
Key physical and cultural milestones in modern human evolution, including genetic divergence of ethnic groups. Image credit: Nick Longrich / author provided
For 200,000 to 300,000 years after Homo sapiens first appeared, tools and artifacts remained surprisingly simple, little better than Neanderthal technology, and simpler than those of modern hunter-gatherers such as certain indigenous Americans. Starting about 65,000 to 50,000 years ago, more advanced technology started appearing: complex projectile weapons such as bows and spear-throwers, fishhooks, ceramics, sewing needles.
People made representational art—cave paintings of horses, ivory goddesses, lion-headed idols, showing artistic flair and imagination. A bird-bone flute hints at music. Meanwhile, arrival of humans in Australia 65,000 years ago shows we’d mastered seafaring.
The Venus of Brassempouy, 25,000 years old. Image credit: Wikimedia Commons
This sudden flourishing of technology is called the “great leap forward,” supposedly reflecting the evolution of a fully modern human brain. But fossils and DNA suggest that human intelligence became modern far earlier.
Bones of primitive Homo sapiens first appear 300,000 years ago in Africa, with brains as large or larger than ours. They’re followed by anatomically modern Homo sapiens at least 200,000 years ago, and brain shape became essentially modern by at least 100,000 years ago. At this point, humans had braincases similar in size and shape to ours.
Assuming the brain was as modern as the box that held it, our African ancestors theoretically could have discovered relativity, built space telescopes, written novels and love songs. Their bones say they were just as human as we are.
300,000 ya skull, Morocco. Image credit: NHM
Because the fossil record is so patchy, fossils provide only minimum dates. Human DNA suggests even earlier origins for modernity. Comparing genetic differences between DNA in modern people and ancient Africans, it’s estimated that our ancestors lived 260,000 to 350,000 years ago. All living humans descend from those people, suggesting that we inherited the fundamental commonalities of our species, our humanity, from them.
All their descendants—Bantu, Berber, Aztec, Aboriginal, Tamil, San, Han, Maori, Inuit, Irish—share certain peculiar behaviors absent in other great apes. All human cultures form long-term pair bonds between men and women to care for children. We sing and dance. We make art. We preen our hair, adorn our bodies with ornaments, tattoos and makeup.
We craft shelters. We wield fire and complex tools. We form large, multigenerational social groups with dozens to thousands of people. We cooperate to wage war and help each other. We teach, tell stories, trade. We have morals, laws. We contemplate the stars, our place in the cosmos, life’s meaning, what follows death.
The details of our tools, fashions, families, morals and mythologies vary from tribe to tribe and culture to culture, but all living humans show these behaviors. That suggests these behaviors—or at least, the capacity for them—are innate. These shared behaviors unite all people. They’re the human condition, what it means to be human, and they result from shared ancestry.
We inherited our humanity from peoples in southern Africa 300,000 years ago. The alternative—that everyone, everywhere coincidentally became fully human in the same way at the same time, starting 65,000 years ago—isn’t impossible, but a single origin is more likely.
Archaeology and biology may seem to disagree, but they actually tell different parts of the human story. Bones and DNA tell us about brain evolution, our hardware. Tools reflect brainpower, but also culture, our hardware and software.
Just as you can upgrade your old computer’s operating system, culture can evolve even if intelligence doesn’t. Humans in ancient times lacked smartphones and spaceflight, but we know from studying philosophers such as Buddha and Aristotle that they were just as clever. Our brains didn’t change, our culture did.
That creates a puzzle. If Pleistocene hunter-gatherers were as smart as us, why did culture remain so primitive for so long? Why did we need hundreds of millennia to invent bows, sewing needles, boats? And what changed? Probably several things.
First, we journeyed out of Africa, occupying more of the planet. There were then simply more humans to invent, increasing the odds of a prehistoric Steve Jobs or Leonardo da Vinci. We also faced new environments in the Middle East, the Arctic, India, Indonesia, with unique climates, foods and dangers, including other human species. Survival demanded innovation.
Many of these new lands were far more habitable than the Kalahari or the Congo. Climates were milder, but Homo sapiens also left behind African diseases and parasites. That let tribes grow larger, and larger tribes meant more heads to innovate and remember ideas, more manpower, and better ability to specialize. Population drove innovation.
Beijing from space. Image credit: NASA
This triggered feedback cycles. As new technologies appeared and spread—better weapons, clothing, shelters—human numbers could increase further, accelerating cultural evolution again.
Numbers drove culture, culture increased numbers, accelerating cultural evolution, on and on, ultimately pushing human populations to outstrip their ecosystems, devastating the megafauna and forcing the evolution of farming. Finally, agriculture caused an explosive population increase, culminating in civilizations of millions of people. Now, cultural evolution kicked into hyperdrive.
Artifacts reflect culture, and cultural complexity is an emergent property. That is, it’s not just individual-level intelligence that makes cultures sophisticated, but interactions between individuals in groups, and between groups. Like networking millions of processors to make a supercomputer, we increased cultural complexity by increasing the number of people and the links between them.
So our societies and world evolved rapidly in the past 300,000 years, while our brains evolved slowly. We expanded our numbers to almost eight billion, spread across the globe, reshaped the planet. We did it not by adapting our brains but by changing our cultures. And much of the difference between our ancient, simple hunter-gatherer societies and modern societies just reflects the fact that there are lots more of us and more connections between us.
when God created us, that’s when
Does this mean there’s hope for liberals, given enough millennia?
Not sure you ever did or will posting crap like this
when God breathed life into man’s body
There is an interesting theory that postulates that very early man gained eventual intelligence though eating magic mushrooms. During the hunting and gathering, very early man sort of micro-dosed on these mushrooms and began to expand the neural (is that a word) activity until they became us...
Makes about as much sense as anything else.
One other and totally unrelated fact I learned a few years back...is that our fore-fathers here in American were wacked most of the time drinking apple jack because no one trusted the water...So the Revolutionary war, consitution and most of the early part of our country’s history was conducted by a bunch of drunks...Ha! Makes sense.
Because I doubt it. We've had ancestors as smart as (or in the case of Democrats, smarter than) us for a really, really long time.
I don’t know when I’ve seen so many assumptions in one place as I just read in that article.
When God breathed His spirit into Adam
The theory of evolution is what happens when you string together facts with mere speculation.
Credit for IQs above 80 is owed to the fierce competition with the Neanderthals. Killing them off was essentially an IQ test of increasing difficulty. No peace treaty was ever possible with them so it was kill or be killed. Africans did not participate in this 20,000 year war, which is reflected in modern genetics.
You question my humanity? I’m not sure how any Christian could say or even think something like that.
Man, how I would like to jump into a time machine and go back and watch it in person!
.
LOL, must’ve been a very frustrating 42,000 years!! Or they used nets!
The Heavenly Father created all souls... and it is the devil that has spent the past 10,000 years plus, creating division amongst the races .. WHY? Because it ‘sells’, some just love to promote their high IQs... and solve nothing. Why the Netherthals population views themselves above the rest ... but are they really viewed that way in the sight of the Creator ... we will find out.
That leaves the Democrats out of the developmental pool.
For as long as I can remember, anyway.
The curse are the naysayers, the politicians of time who stand in the way of mankind improving.
Look at who we have today running things!!
Neanderthals were assimilated not killed off in some fanciful war.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
