Many aspects of our Ancestors’ lives are shrouded in mystery for us all. That cloak of ignorance makes it harder for us to celebrate our Ancestors, and so, so easy for our Ancestors to disappear from our minds, our daily lives, and our spiritualities. One of the many areas of that ignorance is how, and how long ago, human migrated from Asia into North America, becoming the first Native Americans. Now, as Samhain approaches, new evidence shows that Native Americans were very likely here for many thousands of years longer than previously established – solving a mystery I’ve had my whole life!
Blocked by Ice?
As I was growing up, the evidence was clear that Native Americans had been here since at least the retreat of the glaciers around 13,000 years ago, but there was little evidence that they were here much earlier. Plus, before that, glaciers covered Canada (I’ll use current place names for this whole post, though of course these names didn’t exist back then), which would have made it very hard to survive the journey from Alaska to anywhere South of the ice. Imagine trying to travel hundreds of miles over an ice sheet, with only literally stone age technology. What to eat? You’d have to pack all your food with you – there is nothing to eat, and nothing to make a fire with to keep warm, and so on. I’m sure some tried, especially since they didn’t know how far the ice went. Yet, after dozens, then hundreds, of miles of ice, it seems hard to imagine anyone making it.
Also. all that water making up glaciers up to 2 *miles* deep means that millions of cubic miles of Earth’s seawater was locked up in the glaciers, lowering sea levels worldwide. For instance, there are caves elsewhere in the world, which humans lived in and painted, which are now only accessible by diving under water, because at the time all of the caves were above the waves (for instance, check out the Cosquer caves!). This lowering of the sea levels caused the Bering strait, between Alaska and Russia, to be dry ground. This would allow people from Asia to migrate to Alaska, but perhaps not further South (see above). As the glaciers melted starting 13,000 years ago, the resulting rising sea levels closed off the Bering strait (formerly Beringia), but for anyone in Alaska then, ice free areas opened up allowing migration South, to inhabit both North and South America! This fit well with extensive Native American evidence of inhabitation starting from around 13,000 years ago.
Hold on a Minute.
But even thought it was clear that Native Americans had been here since at least 11,000 years ago, Scattered evidence began to appear by the 1900s that some Native Americans may have been here earlier. These included arrowheads called “Clovis points“, the Anzick burial (12,500 years ago), and more. However, many of these (especially any significantly before 13,000 years ago, such as this one suggesting 30,000 years ago) had uncertain dates due to the types of evidence available (for instance, carbon dating needs organic material). So there was a lot of uncertainty that Native Americans had gotten here much before the most recent maximum of the glaciers, the “Last Glacial Maximum”, somewhere around 20,000 years ago. If people had gotten here much before ~ 11,000 years ago, then why wasn’t there clear and abundant evidence? There was clear and abundant evidence after 11,000 years ago, so we know that when there are plenty of people, they leave evidence. Yet, if no people had been here until ~13,000 years ago, why did we keep finding some evidence which might show them here earlier? This was the state of our knowledge, with more (but still ambiguous) data growing through the 1980s, ’90s, and 2000s.
That all just changed. Scientists studying a site in New Mexico just published evidence showing pretty solid radioactive carbon dating of the footprints of human teenagers from between 21,000 and 23,000 years ago! That’s well before the ice! How did they get here? Did Asians cross the Bering strait by boat before the glaciers lowered sea levels and exposed the land? Maybe they went down along the coast, avoiding the ice sheets? The details of the times which the ice retreated and advanced are not simple, and I’ll leave those details to be looked into as you wish. The upshot is that a mystery of whether or not any human was here before 13,000 years ago, which has stood for my entire life is now very likely resolved! Native Americans have likely been here for nearly two dozen thousand years, maybe more!
Yeah, well, those are all just big numbers.
Deep time can be hard to wrap one’s head around. Maybe by comparison to events we know we can better understand what 22,000 years is. The United States Civil War was ~150 years ago, so we’d have to go as far back as the Civil War, then that far back again from there, then again, etc – over 140 times to get back to 22,000 years ago! Or those ancient Egyptian pyramids? The oldest pyramids are around 4,500 years old, so going back to the pyramids, and then to a time before the pyramids as far as the pyramids are ole now, and then do so two more times after that, and that would still not be as old as 22.000 years old!
Perspective using Current Events
Another method I’ve used to try to understand time in general is to scale the time in question to timespans we understand. In this case, we were pretty sure that people have been here for ~12,000 years, and now that appears to be more like 22,000 years. How much of an increase is that? Instead of comparing 12,000 to 22,000 years, how about comparing 12 years to 22 years? 12 years ago is 2009, and 22 years ago is 1999.
In 2009, Barack Obama was president, and the worldwide economy was recovering from the subprime mortgage crisis. You could turn on your TV and watch Grey’s Anatomy, Big Bang Theory, and Survivor (which had already been running for a decade). We had just lost comedian George Carline, gamer Gary Gygax (who invented Dungeons and Dragons), and Author Michael Crichton (who wrote Jurassic Park, the Andromeda Strain, and directed ER).
By comparison – in 1999, Bill Clinton was president, was impeached (acquitted by the Senate) over the Monica Lewinsky scandal, and the Columbine mass murder and the hate crime murder of Matthew Shepard (for being gay) had just happened. On TV, one could watch The Dating Game, Home Improvement, MST 3000, Baywatch, Candid Camera, Star Trek (DSN), and Bozo the Clown (!). The inventor of usable vinyl (in 1926) was still alive (Waldo Semon, who was alive in the 1800s), and Civil War widows from both the Union and Confederacy were still alive. Oh, and today’s popular rapper Lil Nas X had not even been born yet!
What was life like for these Native American teenagers who walked along a muddy bank so many thousands of years ago? Where they playing and joking? Or were they seriously concerned over their next action in the middle of a deadly crisis? Or simply living another day, perhaps foraging for food? Were some of them falling in love, or fostering anger towards another in their group? We can’t know much of that – but at least now we can know that these were a group of human teenagers, probably with many of the same concerns as teenagers today – and we know that this was about 22,000 years ago. These teens knew nothing about atoms, nor antibiotics (indeed, that bacteria and viruses existed), nor of interest rates, horsepower, climate change, giraffes, inflation, cell phones, google, television, mortgages, of the planets as different worlds, or even the Earth as a spherical planet going around the sun (and not the other way around). But they knew joy, fear, dark starry night skies, stories told around the fire, achievement, jealousy, and love. We don’t even know for sure if any of these footprints were made by our literal Ancestors (though of course for those with Native American Ancestry it’s quite possible). These teens may all have died, or that group not mingled with others in the coming millennia. DNA evidence appears to show that the genome of today’s Native Americans split from Asians around 14 to 16,000 years ago, but that doesn’t mean that none of these teens are among the Ancestors of those of us with Native American Ancestors, because such studies only look at certain parts of the genome, and because, out of our millions of Ancestors, many (most!) leave us with zero DNA after dozens of generations. In fact, even for those of us with non-Native heritage, most of us cannot be completely sure we don’t have any Native American Ancestors, unless we know that all 8 of our great great grandparents were born elsewhere (and even then it’s still possible).
I also find it interesting that these people were all barefoot. Maybe shoes simply weren’t worn by anyone yet (the oldest shoes we have found in the world happen to come from relatively close Oregon to this site in New Mexico) but those shoes are from ~10,000 years later! Maybe only the adults had shoes. Maybe they had shoes but had taken them off to play in the mud?
Maybe my joy at this increase in our knowledge also shows me how much we still don’t know. It’s wonderful to learn, and still also wonderful to wonder. I personally feel a freedom in being able to be content to openly not know what I don’t know – and I feel little urge to make up stuff to pretend to fill the gaps in our knowledge. Like anything else we learn, there is still the possibility that new evidence will overturn anything we know (though that’s not an excuse to deny things we have good evidence for, as that excuse is often used today).
Starstuff, Contemplating by Jon Cleland Host
We are assemblages of ancient atoms forged in stars – atoms organized by history to the point of consciousness, now able to contemplate this sacred Universe of which we are a tiny, but wondrous, part.
Dr. Jon Cleland Host is a scientist who earned his PhD in materials science at Northwestern University & has conducted research at Hemlock Semiconductor and Dow Corning since 1997. He holds eight patents and has authored over three dozen internal scientific papers and eleven papers for peer-reviewed scientific journals, including the journal Nature. He has taught classes on biology, math, chemistry, physics and general science at Delta College and Saginaw Valley State University. Jon grew up near Pontiac, and has been building a reality-based spirituality for over 30 years, first as a Catholic and now as a Unitarian Universalist, including collaborating with Michael Dowd and Connie Barlow to spread the awe and wonder of the Great Story of our Universe (see www.thegreatstory.org, and the blog at evolutionarytimes.org). Jon and his wife have four sons, whom they embrace within a Universe-centered, Pagan, family spirituality. He currently moderates the yahoo group Naturalistic Paganism.
Heather is a parent and a scientist raising her four children to explore the world through scientific understanding and with spiritual appreciation of the Universe. She has a Master of Science degree in Physics from Michigan State University, a Bachelor of Science degree in Aerospace Engineering from the University of Michigan, and a Bachelor of the Arts degree in English Literature, also from the University of Michigan. She teaches physics as an adjunct instructor at Delta College, runs the Math Mania program at a local elementary school, has worked at Dow Corning as an engineer and at NASA as an intern, and she has led science outreach workshops for K-12 students through joint programs between NASA and the University of Michigan. She is a naturalistic non-theist, whose faith has been shaped by her childhood within the Episcopal Church, her adult membership in the Unitarian Universalist church, and through Buddhist meditation. She has a passion for bringing science and spirituality to everyone in a fun way, both for her own family and for the wider community of the Earth. She is a co-author with Jon Cleland-Host of Elemental Birthdays: How to Bring Science into Every Party.