Lone Survivors

A million years ago, our Homo erectus ancestors consisted of maybe 20,000 breeding individuals, according to wizards who speculate on the hidden secrets of DNA.  This is similar to the current population of chimpanzees or gorillas.  The ancestors lived in scattered pockets of Africa, at a time when Earth was a paradise of abundant life.  From these ancient roots, a number of hominid species evolved, but only Homo sapiens still survives, at seven-point-something billion and growing.  The chimps and gorillas continue to live in a manner similar to their ancestors of a million years ago.  What happened to us?

Chris Stringer is one of the venerable grandfathers in the study of human evolution.  He’s read the papers, attended the conferences, examined the skulls, and had a ringside seat at the noisy catfights.  This field of knowledge is far from finished.  New specimens continue to be found, and new technology provides deeper insights.  Stringer’s book, Lone Survivors, discusses some primary issues, and the scholarly disputes surrounding them, as they stood in 2012.  He does a pretty good job of providing an overview to a huge and complex subject, but readers with little background are advised to wear life preservers.

I learned a lot about Neanderthals.  They survived 400,000 years on a climate change roller coaster.  They hung out with hippos in warm forests near Rome, and they chased wooly mammoths on frigid treeless tundras.  They had short, stocky bodies that were good for preserving heat, but which required more calories.  Males and females were about the same size, suggesting little division of labor, everyone joined in the hunt. 

The Neanderthal diet majored in the flesh of large game.  Readers who have hunted hippos with wooden thrusting spears know that his is very dangerous.  One site in Croatia contained the remains of 75 Neanderthals, and none were older than 35.  In their clans, there were probably many orphans and few grandparents.  The scarcity of elders, and the small size of their groups, sharply restricted the flow of cultural information from one generation to the next, and from clan to clan.

Some say that Neanderthals lacked shoes and close-fitting clothing.  When Darwin visited chilly Tierra del Fuego, at the bottom of South America, he was shocked to see natives wearing little or no clothing and sleeping naked in the open.  Stringer noted that modern Europeans seem to be poorly adapted to the cold, physiologically.

Cro-Magnons were the Homo sapiens that moved into Europe maybe 45,000 years ago.  European Neanderthals disappeared around 30,000 years ago.  Neanderthals went extinct in the Middle East, Siberia, Gibraltar, and Britain at different times, probably for different reasons.  This was an era of frequent climate zigzags.  When temperatures plummeted, habitable territories shrank, and fewer folks could be fed.

Cro-Magnons apparently had footwear and warm, fitted clothing.  They had better tools for hunting, so their diet was more diverse and dependable.  They were able to extract more nutrients from an ecosystem, so they could survive in places where Neanderthals could not.  They lived in larger groups, and more of them survived to middle age or old age, so more cultural information could be passed to the young.

Large populations are better at preserving cultural knowledge, acquiring new information from outsiders, and generating innovations.  More busy minds interact, exchange ideas, compete, and imagine cool ways for living even farther out of balance.  Witness the city of Los Angeles, where 14 million animals with hunter-gatherer DNA are temporarily able to survive because of a highly complex system of innovative technology.  Note that this innovation has no relationship to foresight or wisdom.  Time is running out on Los Angeles.

On the other hand, less innovation occurs in smaller simpler groups, and that’s often a blessing.  Innovators can be dangerous loose cannons, introducing risky new ideas that result in horrid unintended consequences — like cell phones, automobiles, or agriculture.  Nothing is more precious than a stable, sustainable, time-proven way of living, where the secret to success is simply imitating your ancestors, conforming to the norm, and enjoying life, like the chimps and gorillas do.

When the planet heated up 14,000 years ago, rising sea levels submerged the land link between Australia and Tasmania, terminating the exchange of people, ideas, and gadgets.  Tasmania’s traditional way of life was also squeezed as the warmer climate spurred the expansion of heavy forest.  The natives experienced a cultural meltdown.  “Tasmanians appear to have led an increasingly simplified life, forgoing apparently valuable skills and technologies, such as bone and hafted tools, nets and spears used to catch fish and small game, spear throwers and boomerangs, and anything but the simplest of skin clothing.”

Will climate change have a similar effect on industrial civilization in the coming decades?  Will it slash food production, sharply reduce population, eliminate travel between regions, pull the plug on modern technology, and erase lots of obsolete and unsustainable cultural information?  Could collapse have a silver lining?

Climate change can derail any culture, and drive species to extinction.  It can also produce beneficial conditions, like the unusually favorable climate of the last 10,000 years.  Natural selection rewards species that can adapt to change, and it deletes those that fail.  There is another important variable that is often overlooked — genetic drift — mutations that happen all the time when slight boo-boos occur during cell division.  These tiny defects can provide a barrel of surprises.

We are repeatedly taught that humans are nature’s flawless masterpiece, the glorious conclusion of three billion years of evolution.  But, if Big Mama Nature had experienced slightly different moods over the eons, we might be Neanderthals or Denisovans today (or maybe slime mold).  Climate change and genetic drift are purely random.  The fact that Homo sapiens is the lone survivor among the hominid species is not absolute proof of superiority, but it does indicate a temporary streak of good luck.

Homo heidelbergensis was an ancestor that lived 500,000 years ago.  They had brains ranging in size from 1100 to 1400 cc (modern brains average 1350 cc).  The average Neanderthal brain was 1600 cc — much bigger than ours.  Stringer noted that our brains today are ten percent smaller than our Homo sapiens ancestors of 20,000 years ago.  Is there a message here?

Without words, chimps and gorillas can express contentment, affection, irritation, excitement.  But without complex language, they are more trapped within themselves.  Language took us “into new and shared worlds that were unknown to our ancestors.”  We can talk about the here and now, the past, the future, abstract concepts, feelings, imaginary worlds, and so on.

Later, innovative geniuses invented the use of symbols.  Now we can convert words into patterns of squiggly lines, for example: “computer.”  Writing enables us to communicate with folks in faraway places.  I can read words written by Julius Caesar, and so might the generations yet-to-be-born, in theory.  Industrial civilization cannot exist without symbols — numbers, graphs, pictures, status symbols.  Progress abounds with powerful and dangerous juju.

Stringer is a mild mannered humanist.  And so, he portrays the human journey as one of admirable advancement (the chimps fall down laughing).  On the last page, he confesses a profound doubt.  “Sometimes the difference between failure and success in evolution is a narrow one, and we are certainly on a knife edge now as we confront an overpopulated planet and the prospect of global climate change on a scale that humans have never faced before.  Let’s hope our species is up to the challenge.” 

Stringer, Chris, Lone Survivors: How We Came to Be the Only Humans on Earth, Times Books, New York, 2012.

Cro-Magnon

Once upon a time, long, long ago, musicians Stephen Stills and Judy Collins enjoyed a romance.  Then, Judy sailed away and broke his heart.  Stephen wrote Suite: Judy Blue Eyes, which I recently heard again.  One line made my head spin: “Don’t let the past remind us of what we are not now.”  Why not?  Remembering the past sounds like an excellent idea.  What we are not now is wild and free human beings — normal & authentic.

I just finished Brian Fagan’s book, Cro-Magnon, which describes an important segment of my family history.  The happy news is that there have been three studies of the mitochondrial DNA of modern Europeans, and their genes are primarily indigenous.  The invading farmers from the Fertile Crescent did not exterminate the natives.  The genes of the eastern immigrants are somewhere between 15% and 28% of the modern European DNA. 

It staggers the imagination to contemplate the astonishing wildness, beauty, and vitality of Ice Age Europe.  It’s heartbreaking — and illuminating — when these grand memories remind us of what we are not now.  After reading the book, I feel a much stronger connection to the ancient cave paintings.  Those artists were my ancestors, and their images belong in the family album.  My people once lived in lands inhabited by wooly mammoths, aurochs, bison, and vast herds of reindeer.  They lived beside streams that thundered during salmon runs.  This gave me a sense of homecoming, a powerful remembering.

Fagan does a nice job of describing the world of the Ice Age, and the wild swings of the climate — growing glaciers & melting glaciers.  When the climate warmed, the hunters and their game moved north, and when frigid times returned, they moved south.  The hunters followed the meat, and the meat followed the grass.

“There were at least fifteen to twenty short-term events when temperatures were up to 44.5 degrees Fahrenheit (7 degrees Celsius) warmer than during the intervening colder intervals.”  The climate could swing from pleasant to freezing over the course of a lifetime.  Siberia was once a tropical forest, the Sahara once had lakes and grasslands, and there was a time when you could walk from France to England.

The sad news is that the hunting tribes of Europe became farmers.  This may have been similar to the spread of corn from Mexico to the tribes of the north — an amazing innovation that bit us on the ass, and cast wicked shadows on the unborn generations.  Fagan helped me to better understand the transition to agriculture, in which ongoing innovation in hunting technology played a leading role.

All hominids have African ancestors.  Some of them migrated to Asia, where Neanderthals first walked onto the stage.  Some Neanderthals moved to Europe maybe 300,000 years ago, where they hung out in cool temperate forests.  Their primary weapon was a heavy thrusting spear with a sharp fire-hardened tip.  These were great for killing large slow-moving animals. 

Fagan believes that the Neanderthals were luckless dullards, because they displayed almost no innovative cleverness over vast spans of time.  They were simple and stable, and their dance on this planet may have been far longer than ours will turn out to be — and they didn’t destroy paradise.  What dreary bores!

“Cro-Magnon” refers only to the Homo sapiens clans that inhabited Europe, but our species originally emerged in Africa, maybe 170,000 years ago.  Around 45,000 years ago, some moved into Europe, and within 5,000 years, they lightly inhabited much of the continent.  Cro-Magnons left us the gorgeous painted caves, magic peepholes into fairyland.  Neanderthals went extinct about 30,000 years ago, for unknown reasons.

The trademark weapon of Cro-Magnons was the lightweight throwing spear, tipped with stone or antler.  It was excellent for hunting on open land, and it could kill from a distance.  It made it easier to kill a wider variety of prey, like deer and reindeer.  Thus, there was more meat on the table, more bambinos in the nursery, and more spear-chuckers running around the bloody countryside.  Even during warm eras, European summers were short, and plant foods were limited, so meat was the core source of nourishment.  Homo sapiens have been purebred hunters since day one in Africa.

Later, the bow and arrow arrived.  Bows may have been used 18,000 years ago, based on circumstantial evidence, but the oldest bow found so far was from 10,800 BC.  The bow was a diabolically powerful weapon.  It could be fired from any angle, and quickly reloaded.  It could kill critters large and small from a long distance.  It was great for forest hunting.  Nets, traps, and barbed fish spears also came into use.  Rabbits, birds, and rodents now appeared on the menu — more meat, bambinos, and hunters — and less and less wildlife.  Our consumption of plant foods and shellfish increased.

Around 12,900 years ago, the Younger Dryas period brought frigid weather back again, for a thousand years.  It brought severe droughts to the Near East, and the humans adapted by harvesting and planting grass seeds.  And the rest, as they say, is history.  The combination of excess cleverness, deficient family planning, and climate change put us on a bullet train to global catastrophe.

“Within a surprisingly few generations, the people of the Near East and southeastern Turkey were entirely dependent on farming.  When wetter conditions returned at the end of the Younger Dryas, the new economies spread like wildfire across Anatolia and into southeast Europe, where they were well established before eight thousand years ago.”

What we know about human evolution and Ice Age Europe is quite fragmentary.  Time, glaciers, and civilization have taken a big toll on the meager evidence.  The timeline is full of holes, the dates are controversial, the theories are controversial, and the research continues.  Fagan’s book also has some holes, which can be filled by a visit to Wikipedia.

Annoyingly, he inserted a number of ideas unsupported by hard evidence, based on speculation.  For example, Neanderthals probably didn’t have complex language because they persisted in living in a simple manner.  Their primitive brains may have lacked the neural circuits necessary for feverish innovation and pathological ecocide. 

Fagan is the captain of the Homo sapiens cheerleading squad.  He gushes with praise for our unbelievably clever species.  “Effective technology, an acute self-awareness, and an intimate relationship with the environment made the Cro-Magnon personality practically invincible.”  In frigid regions of Europe, they “adapted effortlessly to the ever-colder conditions.”

I’m glad that I read this book, because I learned a lot from it, and I will not forget it.  The entire era of civilization has existed during an unusually long period of warm and stable weather.  Our food production system is fine-tuned for this climate, and it’s going to have tremendous problems as the planet gets hotter and hotter.  Fagan helps us remember the scary roller coaster of climate history, and how it mercilessly hammers the unlucky, over and over again, big brains and all.

Given the fact that we’re currently beating the stuffing out Big Mama Nature, the gushing praise for human intelligence and innovation emits a noxious cloud of stinky funk.  Where is the line between brilliant innovation and idiotic self-destruction?  Are they the same?  Is it possible that simple and stable do not mean stupid?  These questions should not be swept under the rug.  We really, really need to remember what we are not now.  We need to discover the long lost treasure.

The next book on my voyage is The Humans Who Went Extinct, by Clive Finlayson, who is far more sympathetic to our Neanderthal relatives.  Sounds interesting.  Stay tuned.

Fagan, Brian, Cro-Magnon – How the Ice Age Gave Birth to the First Modern Humans, Bloomsbury Press, New York, 2010.