Showing posts with label Ice Age. Show all posts
Showing posts with label Ice Age. Show all posts

Monday, July 15, 2019

Wild Free and Happy Sample 19


[Note: This is the nineteenth sample from my rough draft of a far from finished new book, Wild, Free, & Happy.  I don’t plan on reviewing more books for a while.  My blog is home to reviews of 201 books, and you are very welcome to explore them.  The Search field on the right side will find words in the full contents of all rants and reviews, if you are interested in specific authors, titles, or subjects.] 

Climate Shifts?

So, what caused megafauna extinctions?  The two primary suspects in this mystery are hominin hunters and climate change.  After numerous rowdy fistfights at scholarly conferences, the overhunting theory has become the most widely accepted.  Quite a few still believe climate change was a secondary factor, because the swings between hot eras and frosty ones could cause substantial shifts in a habitat’s vegetation.  When tundra became forest, mammoths no longer lived in paradise.  Their numbers likely declined, and their groups could have become more isolated.

When the climate warmed, hippos and monkeys migrated into Europe, joining the woodland rhinos, elephants, boars, and deer.  Tundra became boreal forest, and the cold adapted critters no longer enjoyed optimal conditions.  This could have weakened them, and made them more vulnerable to hungry hominin hunters. 

Then, when temperatures dropped, ice sheets advanced again, and the good old days ended for the warmth loving critters.  Woodlands were displaced by tundra and taiga — good habitat for lemmings, arctic foxes, reindeer, woolly mammoths, and woolly rhinos. 

Peter Ungar discussed research in Greenland, where scientists bored deep into the thick 150,000 year old ice sheet.  In the ice core samples, the annual layers of ice buildup contained details about climate trends.  Patterns could remain stable for thousands of years, and then suddenly change.  The emergence of agriculture and civilization only became possible with the arrival of the current, unusually long warming trend, which began about 11,600 years ago.  It followed a 1,200 year stretch of intense cold.  The transition from intense cold to the modern warm trend occurred during one lifetime.  A lass who was born in an arid tundra would see the land transform into a young forest by the time her hair was gray.

Now, gaze at the globe on your desk.  As Earth makes its annual joyride around the sun, its axis tips.  When the northern hemisphere tips closer to the sun, it’s summer time.  Six months later, summer begins in the southern hemisphere, and winter arrives up north.  The regions close to the equator consistently receive the most solar energy throughout the year, so they are Earth’s warmest — the tropics.  Both the North Pole and the South Pole get the least solar energy, so they are icy year-round. 

On your globe, note that most dry land regions on the planet are north of the equator.  Also, at the top of the world, the northern edges of North America, Europe, and Asia extend into the Arctic Circle.  Consequently, the northern hemisphere has experienced a number of intense glaciation cycles.

The southern hemisphere has far less dry land, and far more ocean area.  The surrounding oceans retain heat, and encourage a more moderate climate.  In the southern hemisphere, the bottom edges of South America, Africa, and Australasia do not come close to the Antarctic Circle.  For these reasons, glaciation events have been less extensive.

The Last Glacial Maximum (LGM) was the frigid peak of the most recent glacial cycle.  Ice sheets began growing about 33,000 years ago.  Glaciation peaked between 26,500 and 19,000 years ago.  Large regions of northern Europe, Asia, and North America were buried under ice sheets up to one mile (1.6 km) thick.  During the LGM, climate conditions were similar across these northern regions.  Glaciers retained so much frozen water that sea levels were 410 feet (125 m) lower than today.  A lass could walk from Ireland to Scandinavia or France without getting her feet wet. 

Bernardo Araujo’s team studied up-to-date climate models for the last 122,500 years.  For 19 regions, they compared the dates when humans arrived, with the dates when megafauna species went extinct.  They found that humans were entering Europe and Central Russia about 45,000 years ago.  In the colonized regions of Eurasia, extinction dates began about 40,000 years ago, and continued until about 10,000 years ago — the longest of the megafauna extinction cycles outside of Africa.

Araujo emphasized that our colonization of Eurasia was a significant turning point in the human colonization of the planet.  It was the first time that our fully tropical species was moving into regions that were colder than the conditions for which evolution had fine-tuned us.  It was far more challenging for humans to survive in snow country.

Fernando Fernandez also found no connection between climate patterns and extinctions.  He wrote that there were essentially two pulses of extinctions in Eurasia.  The first pulse was from 45,000 to 20,000 years ago, across the southern latitudes.  The second pulse was from 14,000 to 9,000 years ago, in the northern latitudes.

In North America, Fernandez reported a much quicker extinction spasm.  It mostly occurred between 13,500 and 11,000 years ago.  Experts still disagree when humans arrived on the continent, suggesting dates ranging from 20,000 to 13,000 years ago.  By the time humans entered North America, they had developed effective tools and strategies for succeeding in snow country, making a faster dispersal possible.  South American extinctions were mostly between 13,000 and 7,800 years ago.

Fernandez presented a list of arguments why climate change was not the primary cause of megafauna extinctions.  Climate swings affected the whole planet, but the extinction spasms occurred at widely different times, in different places — not everywhere at the same time.  The timing of extinctions does not closely correspond to the timing of glacial cycles.  Preceding the megafauna extinction spasms were 31 earlier glacial cycles which wiped out few if any species. 

Extinctions occurred first on continental mainlands, while species on isolated islands in the same region, with the same climate, survived much longer.  When extinctions took place in a region, there is no evidence that plant species were zapped by temperature swings at the same time.  It was the large animals that blinked out (the preferred game of hunters).  Small animals did not vanish in the same era (like they might have during a climate shift).  He did say that glacial cycles could have stressed ecosystems, making some species less resilient.

Baz Edmeades noted that most of Africa lies between the Tropic of Cancer and the Tropic of Capricorn, the equatorial belt.  When there were extinction spasms in the equatorial belt, there was no rise of extinctions in regions where hominins had not yet arrived.  The extinctions were limited to Africa and southern Asia — tropical regions where hominins resided.

OK!  So, based on what I know today, I am convinced that climate change was not the primary cause of megafauna extinctions.  I am also thoroughly convinced that the pattern of extinction spasms was closely related to the early emergence of advanced hominins in Africa, and to the later pattern of world colonization by humans.

I remain befuddled by one mystery.  During the North America extinction spasm, most of the megafauna species that survived were not indigenous. They were immigrants from the Old World, like moose, bison, caribou, elk, deer, grizzly bears, black bears.  Indigenous megafauna got hammered.  Super-speedy pronghorn antelope were among the few to escape extinction.  The implication here is that the Old World megafauna immigrants had arrived at about the same time as the Siberian hunters, and these foreigners were fully aware that humans were dangerous murderers — run!  I was not able to find information confirming that “about the same time” is true.

William Stolzenberg presented a different twist.  He shared a fascinating story about Joel Berger.  Early in the twenty-first century, when Berger was working near the Teton Range of Wyoming, wolves from Yellowstone began wandering back into the region.  They had been absent for 50 years, victims of a predator eradication project.  For 50 years, moose and elk had not been bothered by serious predators.  Berger freaked out.  He tried scaring the moose with wolf calls and scents.  No response.  They had completely forgotten their natural fear of wolves.  So, the wolves casually walked past the clueless moose mothers, and hauled away their calves.  Eventually moose learned that wolves were dangerous.

Global Serengeti

Baz Edmeades grew up in South Africa, where he enjoyed observing the remnants of African megafauna at Kruger National Park.  His deep interest in archaeology and evolution led him to read Björn Kurtén’s book on Pleistocene Europe.  He was shocked to discover that 15,000 years ago, hyenas, leopards, and lions roamed Europe, and they closely resembled the animals he watched in Africa.  Woolly rhinos and mammoths had cousins at Kruger.  Not that long ago, large animals were incredibly abundant.  Grassland regions of Europe were once a wildlife wonderland, like Africa’s Serengeti.

North and South America also had Serengeti-like grassland regions.  Dan Flores wrote that the Great Plains used to be home to many species of large mammals, none of which had evolved adaptations for living near packs of aggressive bloodthirsty tropical primates with spears, dogs, and fire.  Many blinked out.  Five hundred years ago, when European colonists began arriving in great numbers, with highly advanced technology, life on the American Serengeti got blindsided with astonishing speed and efficiency.

Today, many documentaries and nature programs present images of the African megafauna that still survive in protected areas, like the Serengeti.  These images of lions, zebras, giraffes, and baboons inspire astonishment among the wretched mobs trapped in sprawling, grungy, concrete landfills like New York City or London.  But, compared to the Serengeti of 2 million years ago, the twenty-first century Serengeti is much diminished.

Two million years ago, all the other continents were also astonishing Serengetis.  Earth was one big wonderful celebration of abundant life.  The critters of every ecosystem had coevolved with each other, resulting in functional relationships between the eaters and the eaten.  Loose cannon critters were not yet molesting the sacred dance.  Today, of course, a hurricane of swarming tropical primates has reduced Planet Serengeti to Planet Train Wreck.

It’s heartbreaking to comprehend that this staggering tragedy was driven by the innocent unintended consequences of thousands of years of gradually accumulating more and more clever innovations.  Today, the rate of extinctions is in the stratosphere.  Innovation and technology have given us the ability to thoroughly obliterate healthy ecosystems faster than ever before.  We call this “progress,” one of our god words.  Another one is “growth.”

In North America, when humans arrived, there were at least nine species of big cats, and seven species of elephants.  The biodiversity was incredible — beavers as big as bears, two-ton buffaloes, armadillos the size of VW Beetles

Mammoths emerged in South Africa about five million years ago.  By 2.6 million years ago, they had spread across Eurasia and North America.  Around 190,000 years ago, all mammoths in Europe had evolved the woolly look.  Until 14,000 years ago, mammoth country ranged from Western Europe to Siberia to New England to Mexico.  The last mammoths survived until about 3,700 years ago, on Wrangel Island, off the coast of Siberia.

Aurochs once ranged from England to Korea, and south to India and North Africa.  Rhinos once ranged from Africa to Europe to Sumatra.  Leopard country spanned from southern Africa to England, to Java.  Short-faced hyenas were as big as lions, and their addresses included India, China, Transvaal, and Europe.  And on and on….

Tim Flannery mentioned Neanderthals, who had significantly larger brains than humans.  They were long-time residents of Eurasia that had coevolved with the other large animals.  For hundreds of thousands of years, they coexisted with mammoths, straight-tusked woodland elephants, and two species of woodland rhinoceros.  Scholars tend to regard Neanderthals as dullards.  Ecological stability is not a sign of pathological intelligence.

Mother Africa

Around 5 million years ago, the climate in Africa was getting cooler and dryer, forest area was being displaced by expanding savannah.  The ancestors of hominins learned ways to survive in the changing conditions.  Our hominin ancestors were bipedal at least 3.6 million years ago.  Somewhere around 2.5 million years ago, the climate in Africa once again entered a cooler and dryer pattern. 

By this time, our hominin ancestors were getting better adapted to savannah living.  They were bigger and smarter, using stone tools.  They may have been cooking with domesticated fire, but we’ll never know when the first fire was kindled.  As previously mentioned, hominin evolution was influenced by having the ability to regularly dine on cooked food, which significantly tweaked the design of our teeth and digestive tracts.  This implies that domesticated fire appeared early in the game.

The series of megafauna extinctions that occurred during the hominin era began in Mother Africa.  Lars Werdelin, an expert on ancient carnivores, wrote that beginning around 2 million years ago, large carnivore species began to gradually decline.  Hominins were becoming regular hunters, and they were eating more meat.  Carnivore extinctions accelerated around 1.5 million years ago.  Coincidentally, Homo erectus emerged around 1.5 million years ago.   Erectus was the first advanced hominin, having a brain larger than average for its body size.  This era corresponds to the oldest known evidence of domesticated fire.  Today, only two percent of the original African large carnivore species still survive.

Werdelin assumed that hominins were not deliberately hunting large carnivores, which would have been insanely dangerous.  The extinctions were likely due to a decline in herbivores — the prey that carnivores depended on.  Was climate change reducing the forage that herbivores required for survival?  Small carnivores were not in decline, which would have been the case if ecosystems were being walloped by a climate shift.  Werdelin believes that hominins had become successful competitors for the traditional carnivores, both of whom were eager to dine on the same prey. 

Baz Edmeades noted that the African continent was loaded with megafauna 1.8 million years ago, but many were gone by 1.4 million years ago.  In the good old days, Africa had nine species of big cats (three today), up to nine species of elephants (one today), and at least four types of hippos (one today).  There were giant antelopes, giant hyenas, giant pigs, giant monkeys, giant baboons, and many others — all gone.  Over the course of many thousands of years, the consequences of hunting just a bit too hard accumulated. 

Some species that disappeared in Africa continued to survive on other continents.  Edmeades emphasized that during the African wave of extinctions, there were no corresponding extinction blips in Siberia, Europe, Australia, or the Americas.  In these other regions, most megafauna species thrived for another million years.  A jury would not convict climate change for the extinctions in Africa.

Monday, April 15, 2019

The Smart Neanderthal



Clive Finlayson is especially fascinated by two things, Neanderthals and birds.  Since 1989, he has been excavating caves in Gibraltar, on the north shore of the Mediterranean, where Neanderthals lived from 127,000 to 32,000 years ago.  Gibraltar is the place where the last Neanderthals tearfully bid farewell to this magnificent planet.  Later, after they were gone, Homo sapiens lived in these caves, beginning maybe 30,000 years ago.  There is no evidence of them being in living contact at the Gibraltar site.

For decades, many scholars have adopted the belief that we Homo sapiens were superior to Neanderthals.  They imagine that when humans invaded Neanderthal territory, the inferior species was helplessly overwhelmed and exterminated.  This belief is known as the replacement model, which assumed that we could never meet other humans without wiping them out.  History is loaded with replacement stories.

Beliefs are based on assumptions, which are sometimes daffy balderdash.  Over time, beliefs that pass from one generation to the next can mutate into illusions that are perceived to be certain truths.  Human supremacists really annoy Finlayson, and he has written three books to spank them — Neanderthals and Modern Humans (2004), The Humans Who Went Extinct (2009), and The Smart Neanderthal (2019).  The new book is an enjoyable, well written mystery story, in which the brainy hero (Finlayson) confronts the dodgy beliefs held by many mainstream scholars.

It’s not surprising that folks who have spent more than 30 years studying Neanderthals actually accumulate a lot of experiences and insights.  They learn things that scholars in faraway college towns never do.  The myth of progress is only a few centuries old, and it perceives that all previous generations were inferior — especially our prehistoric relatives.  The human supremacists in academia have generated a list of advanced characteristics that Neanderthals lack.  In his new book, Finlayson examines this list, item by item, and presents evidence to the contrary.  He concludes that humans and Neanderthals were equally intelligent, but not equally lucky in the survival lottery.

Of all the prehistoric hominins, we know Neanderthals best, because we have discovered a number of sites where they lived in Eurasia.  In caves, evidence of days past is far less likely to be blown or washed away, and more likely to be preserved and found.  Over time, layers of stuff build up, with newer ones covering the old.  Scientists assign dates to each layer, and document the artifacts found.

What makes the book especially interesting is that he uses his love of birds to support a number of his arguments.  The caves at Gibraltar contain the remains of 160 species of birds.  The region was once a wonderland for the winged ones, but not now.  “Their world has been destroyed by civilized man in a few centuries.”

Human supremacists assert that dimwitted Neanderthals were incapable of catching speedy prey, like birds or hares.  So Finlayson visited Spain, and watched an old gent attract 300 large vultures by putting out some carrion.  They surrounded him, and happily took food from his hand.  Another time, he went to an island off the coast of Scotland, where it was the breeding season for 150,000 gannets.  None took flight as he strolled through them, instead they pecked his legs bloody.

Some birds respond to danger by flying away.  Others, like the stone curlews, have natural coloration that provides excellent camouflage.  When danger appears, they freeze, and become nearly invisible to predators.  They only take flight if the intruder makes a sudden movement.  Finlayson has calmly walked right past frozen curlews, and could have easily snatched them.  Sometimes speedy hares will freeze in the presence of danger, allowing their camouflage to render them invisible.  Finlayson has walked very close to frozen hares.

The 300,000+ year saga of Neanderthals was an era of roller coaster climate shifts.  Most of their time on Earth was colder than average.  Some climate shifts happened suddenly and sharply.  Children were sometimes born in a steppe habitat which, decades earlier, had been woodland when their grandparents lived there. 

Between the Arctic, and the Mediterranean, there were several climate zones — ice, tundra, steppe, and woodland.  When the climate plunged into frigid periods, glaciers and ice sheets expanded in the north, which compressed the zones to the south.  There were times when the ice sheet extended from Scandinavia to northern Germany, and covered most of the British Isles.  At times, large areas of France were tundra.  The Mediterranean Sea, a large body of warm water, moderated the climate of southern Europe, so the temperature swings were less intense in Gibraltar, and wild foods remained abundant.

One indicator of climate shifts is the types of bones found at various time periods in the layers of cave crud.  The layers associated with Neanderthals usually indicated warm, moist, woodland or forest.  Woodland conditions were identified by the bones of aurochs, red deer, boar, cave bear, leopard, giant deer, and temperate rhinoceros. 

It’s important to understand that the more recent sites, which are associated with humans, often indicate steppe-tundra conditions, when the land was cold, dry, open, and treeless.  Steppe-tundra conditions were identified by the bones of woolly mammoth, woolly rhinoceros, horse, musk ox, ibex, moose, Artic fox, and reindeer.

The human supremacists regularly ridicule Neanderthals for displaying little innovation.  For 300,000+ years, their primary weapon was the thrusting spear.  Obviously, a stable and functional way of life was glaring evidence of low intelligence!  But Neanderthals were woodland creatures who excelled at ambush hunting.  For them, a thrusting spear was the perfect tool.  For humans, who lived in steppe-tundra habitat, it was the opposite of excellent, because a wide open landscape had no trees or brush to conceal their presence.  Their weapon was the javelin.

The latest technology is giving archaeologists the ability to extract more information from the stuff they dig up.  For example, plant pollen.  Long ago, hyenas ravenously devoured carcasses, including their intestines, which contained pollen from the surrounding vegetation.  Fossilized hyena turds (coprolites) have preserved this pollen, allowing scientists to discover the mix of plants in the ecosystem during different time windows.  This indicated current climate conditions.

Finlayson dismisses the notion that Neanderthals were driven to extinction by humans, and wonders if they may have resisted human expansion.  He believes that an increasingly cold climate was shrinking their traditional woodland habitat, and fragmenting their population.  After surviving numerous eras of cold, the latest one pushed them a bit too hard — bad luck drove them extinct.

One point Finlayson doesn’t mention is that Neanderthals emerged 300,000+ years ago in Eurasia, where they evolved in a temperate climate.  Their bodies were stockier to give them better cold tolerance.  Humans emerged in Africa maybe 300,000 years ago.  They evolved in a tropical climate, where they developed better tolerance of heat, and became skilled at grassland hunting. 

When humans wandered into the grasslands of Eastern Europe 36,000 years ago (the “European Serengeti”), their tropical bodies were not fine-tuned for freezing weather.  At this point, their choices were to either to turn around and return to home sweet home, or innovate like crazy and struggle to survive in a hostile climate where large game was abundant.

The human supremacists shout that the humans were simply too smart to fail.  They claim that a miracle occurred 50,000 years ago, when genetic mutations caused human intelligence to skyrocket.  This was called the Great Leap Forward, or the Cognitive Revolution.  Finlayson says “Bullshit!”  Genetic research has found zero evidence of this.

What genetic research has found is clear evidence that Neanderthals and non-African humans interbred.  East Asians have 2.3 to 2.6 percent Neanderthal DNA, and Western Eurasians have 1.8 to 2.5 percent.  Markers of these hot romances are as old as 100,000 years ago, and as recent as 37,000 years.  Today, humans of various ancestries carry different segments of Neanderthal DNA.  Thus, up to 20 percent of the Neanderthal genome might still exist, scattered throughout the vast human herd.

Supremacists assert that only humans were brilliant enough to dine on marine life.  Oddly, the Neanderthals at Gibraltar ate mollusks, seals, dolphins, herbivorous mammals, tortoises, and birds.  But, but, but… only humans were smart enough to paint caves and make ornaments.  Recent research is raising doubts (someone was apparently painting caves 64,800 years ago).  Indeed, humans likely learned many tricks from the Neanderthals. 

To make claims of cognitive superiority based on the artifacts of material culture is silly.  The writing tools I used in 1970 were extremely crude compared to the laptop I’m using now.  Has my brain become far more powerful?  Compared to my grandparents, is my brain actually better?

Uncomfortable doubts are growing, with regard to the ultimate value of intelligence.  Neanderthals lived for 300,000+ years, in a manner that had the appearance of genuine sustainability.  They have not been associated with megafauna extinctions.  Following the human colonization of Europe, there was a wave of megafauna extinctions, which occurred between 30,000 to 12,000 years ago. 

Since then, aggressive cultures of our godlike species have blindsided every ecosystem on Earth.  The supremacists leap to their feet, clapping, cheering, and celebrating the wonders of perpetual growth and progress.  Big Mama Nature laughs and laughs, as she prepares some potent surprises to rubbish our illusions of grandiosity.  Soon she’ll be serving us an all-you-can-eat banquet of humble pie.

Finlayson, Clive, The Smart Neanderthal, Oxford University Press, Oxford, 2019.

Thursday, February 14, 2019

Wild Free and Happy Sample 09


[Note: This is the ninth sample from my rough draft of a far from finished new book, Wild, Free, & Happy.  I don’t plan on reviewing more books for a while.  My blog is home to reviews of 199 books, and you are very welcome to explore them.  The Search field on the right side will find words in the full contents of all rants and reviews, if you are interested in specific authors, titles, or subjects.] 

The Dance of Hominin Evolution

Experts have endless lively disputes about many aspects of hominin evolution.  There were many predecessors to Homo sapiens, but an accurate lineage of the hominin family tree does not exist, and probably never will.  The physical evidence discovered so far is extremely incomplete.  It’s like a million piece jigsaw puzzle where more than 99 percent of the pieces are missing, and most of these have disintegrated over time.

Evolution does not resemble automobile assembly plants, where production of 2018 models completely ends on a fixed date, and the process of building new and improved 2019 models begins.  The transition from one species to the next is a blurry process that can take hundreds of thousands of years, and isolated groups of the same species can evolve in significantly different ways. 

In addition to arguments over the branches of the family tree, the dates assigned to specific events are also controversial and inconsistent.  Technology for dating specimens has advanced over the years, and different technologies often produce very different dates for the same bone or artifact.  Also, ongoing field work continues to make new discoveries.  So, did Homo sapiens emerge 190,000 years ago, or 300,000?  Did they arrive in Europe 50,000 years ago or 36,000?  And so on.  Numbers are slippery.

If we step back a bit, and disregard numeric dates, there is general agreement on a number of big picture trends.  Homo erectus is much older than Neanderthal, and both are older than Homo sapiens.  Homo sapiens evolved in Africa, and Neanderthals did not.  Erectus and Neanderthals are not associated with megafauna extinctions, but our species certainly is.  For the purposes of this book, the trajectory of trends is important — event A preceded event B.  All numeric dates presented here are controversial.

Although the Earth Crisis has roots much older than Homo sapiens, our species is playing a starring role in this catastrophic tragedy.  For this reason, the following chapters will primarily focus on humans, and the emergence and expansion of some highly destructive cultures.  But first, a few comments on two notable cousins.

Erectus and Neanderthal

Homo erectus emerged maybe 1.9 million years ago, and eventually spread across some of the warmer regions of Africa, Asia, and Europe.  They may have been an early ancestor of modern humans.  Erectus hunted, gathered, and used stone tools.  They were the first hominins to evolve a larger than average brain, and they may have been the first to domesticate fire.  Erectus maybe walked off the stage somewhere between 200,000 and 50,000 years ago.  Their long era of existence does not correspond to extinction spasms or serious ecological injuries.  Erectus apparently lived on Earth much longer than Neanderthals did.

Neanderthals probably evolved north of the Mediterranean, not in Africa.  Their remains have been found in Siberia, the Middle East, and Europe.  The earliest discoveries date to maybe 350,000 years ago.  We share up to 99.9 percent of our DNA with them.  Because they lived in non-tropical regions, they evolved thick bodies with large bones that provided greater strength and better cold tolerance.  Elizabeth Kolbert noted that modern humans have up to four percent Neanderthal DNA. 

Erectus, on average, had 1,000 cc brains.  Neanderthals were the brainiest hominins, at 1,600 cc.  Sapiens averages a modest 1,350 cc.  Could our smaller brains be the result of having access to cutting edge new technology (javelins, harpoons, bows and arrows, etc.)? 

Kathleen McAuliffe reported on research finding that human brains have shrunk about 10 percent in the last 20,000 years.  The Homo sapiens with the biggest brains lived in Europe 20,000 to 30,000 years ago.  They were the Cro-Magnons, who had to overcome the many new challenges of surviving in snowy ecosystems, while fending off hungry cave lions, cave hyenas, and saber-tooth cats.  The shrinking brain trend has been found in China, Europe, Africa, and even Australia, which remained Stone Age until 1788.  Why?  Perplexed experts propose some theories, but they don’t know for sure. 

One study found that brains get smaller as population density increases.  Tim Flannery suggests that modern consumers live like cattle on a feedlot, all our needs conveniently provided.  We no longer have the skills or knowledge to survive in the wild.  Thirty species of animals have been domesticated, and for every one of them their brain volume was 10 to 15 percent smaller than their wild ancestors.  Some think that humans domesticated themselves.

Anyway, the trademark Neanderthal weapon was a heavy thrusting lance.  Hunters had to slowly, silently, and very skillfully approach the prey undetected, then suddenly charge the animal, firmly gripping the spear with both hands, and ram it deep into its flesh.  Readers who have hunted hippos with wooden thrusting spears know that this can be very dangerous.  One site in Croatia contained the remains of 75 Neanderthals, and none were older than 35.  Many of their bones had healed fractures, suggesting painful accidents or encounters with fierce animals.  Dying of old age was unlikely.

The climate of the Neanderthal era was like a roller coaster.  In Europe, they were pounded by an era of extreme cold maybe 70,000 years ago.  From maybe 50,000 to 30,000 years ago, the climate was a spastic freak show.  Clive Finlayson noted that the climate often flip-flopped between warm periods and intensely frigid.  Radical shifts could arrive suddenly, and last hundreds or thousands of years, all across Eurasia.  Youngsters might grow up in a chilly steppe ecosystem that used to be a comfortable forest in the days of their grandparents.

Would Neanderthals have become the modern global primate if Homo sapiens had blinked out in Africa?  I sometimes wonder if real estate was a significant limiting factor.  Caves were luxurious addresses during glacial centuries, compared to hide-covered teepees or huts.  The primo caves were south (sun) facing, and ideally overlooked the seasonal migration routes of animal herds.  But there was a limited number of caves, and many were not vacant.  Neanderthals were always welcome dinner guests when they stumbled into caverns inhabited by hungry, jumbo-sized cave lions, cave hyenas, and cave bears.

In warmer and wetter periods, glaciers retreated, and tundra transformed into forest and grassland, habitat for critters like red deer, horses, and moose.  In colder and drier periods, glaciers advanced, forest retreated, and tundra returned, as did mammoths, woolly rhinos, and reindeer.  Neanderthals listened to their growling tummies, and went where the meat was.  They migrated northward in warmer eras, and retreated south when blast freezers returned.  The last Neanderthals died on the sunny shores of the Mediterranean, in Gibraltar, maybe 40,000 to 28,000 years ago.  This was definitely after the arrival of humans in Western Europe, and before the spasm of megafauna extinctions on the continent.

Our human supremacist culture routinely preaches that Neanderthals were pathetic dullards.  During their long vacation in Europe, maybe 270,000 years, Neanderthal technology didn’t change much.  From the supremacist perspective, Neanderthals’ 350,000 year era of stable, low impact, ecological sustainability was indisputable proof of low intelligence. 

Elizabeth Kolbert absolutely disagreed.  Neanderthals lived in Europe for a very long time while affecting their ecosystem no more than any other large mammals.  Flannery noted that, for hundreds of thousands of years, Neanderthals coexisted with straight-tusked elephants, mammoths, and woodland rhinos — without driving them extinct.  If humans had never wandered in from the Middle East, Europe might still be a wild, free, and happy celebration of Neanderthals, Irish elk, saber-tooth cats, straight tusk elephants, and aurochs.  What’s wrong with that?

Everything!  The supremacists leap to their feet, jump up and down, spitting, shouting, smashing bottles.  Humans are blessed by incredible intelligence, brilliant innovation, complex hunting weapons, sophisticated language skills, artistic creativity, decorative ornaments, and the powerful ability to invent totally irrational beliefs, accept them as absolute truth, and exterminate large numbers of nonbelievers.  Ancient mystical stories invented by Homo sapiens proudly assert that Homo sapiens is the absolute Crown of Creation, and the rest of the family of life was provided for our sustenance, amusement, and assorted perversions.

OK.  Stop right here.  Reread the list of human blessings in the previous paragraph.  For the most part, these are not characteristics of species that managed to live sustainably for more than a million years, like the chimps, baboons, lions, horses, and on and on — “ordinary animals” in other words.  In the big picture, it’s not irrational to conclude that the unusual intelligence we have acquired is powerful, dangerously irrational and destructive, and has become the primary threat to our continued existence.

For 150+ years, it has been a normal and respectable tradition for scholars and theologians to line up and urinate on the stupid Neanderthals.  European intellectuals were quite sure that the Garden of Eden was located rather close to London.  They were stunned and bewildered by the growing evidence that the ancestors of all hominins trace back to Mother Africa.  All Homo sapiens living 50,000 years ago had beautiful dark skins.   Oh my God!  It can’t be true!  Horror!

In 2014, Paola Villa and Wil Roebroeks reexamined the traditional beliefs in Neanderthal inferiority, to see if the latest archaeological research still supported them.  They did not find compelling data.  They also pointed out that the traditional beliefs of human superiority in language, symbolic communication, cognitive abilities, and abstract thinking were impossible to prove via archaeological data.  These were the biased opinions of supremacist imaginations.  Science is not required to be rational, and very often isn’t.

Sustainability Doesn’t Suck

Anyway, Neanderthals demonstrated that bipedal primates with huge brains can live sustainably for several hundred thousand years, in extremely challenging conditions, without agriculture, metal making, animal enslavement, fish mining, deforestation, or writing.  In fact, stability is not a problem or flaw.  Stability sounds like a fun and healthy alternative to mindless perpetual growth, fanatical eco-destruction, and devastating hurricanes of irrational illusions.

Clive Finlayson reminded us that no animal species can foretell the future.  When life is comfortable, and the ecosystem is not being ravaged, the safe and intelligent option is to be conservative, and remain on the well-worn time-proven path.  But when the <bleep> hits the fan, and traditions totally fail, innovation might be a less dangerous option.  The path of innovation is risky, often leading to unintended consequences and bloody surprises.  In worst case scenarios, innovation can backfire spectacularly, as 7+ billion people are now painfully discovering.  Yikes!

Chris Stringer reminded us that the myth of progress is a new idea.  The notion of utopia-bound continuous improvement is a bit over 200 years old.  Civilization was imagined to be an upward spiral. 

But in earlier civilizations, mobs of loonies were furiously mowing down ancient forests, triggering landslides, flash floods, and harbors choked with silt.  Each new generation inherited an ecosystem that was obviously in worse condition.  The passage of time was seen as a downward spiral of decay and decline, an inevitable one-way descent into social and ecological Armageddon. 

Hesiod, an ancient Greek thinker, described the glorious days of his venerable ancestors as the Golden Age, when men were pure and lived like gods.  It was followed by a descent into the Silver Age, the Copper Age, the Bronze Age, and finally the Iron Age, when men were violent, foul-mouthed, and fascinated by every form of evil.

Stringer noted that the wizards of modern society are possessed by an overwhelming and irrational blind faith in progress and perpetual growth.  We are far more advanced than Neanderthals, and they were better than Erectus.  You and I are lucky to enjoy the amazing pinnacle of billions of years of evolution.  Stringer does not see this as proof of divine destiny.  He believes that the fact that Neanderthals blinked out, and we didn’t, was largely a result of chance.  We survivors were assisted by the good fortune of being in the right place at the right time.

For example, about 70,000 to 75,000 years ago, the Mount Toba super volcano erupted on the island of Sumatra, spreading enormous amounts of ash.  In some regions of India, up to 19 feet (6 m) of ash accumulated.  Much incoming sunlight was blocked, and global temperatures may have dropped by 3° to 5°C for several years.  Others imagine an intense thousand year instant ice age.  Still others suspect far less global impact.  One theory, presented by geneticists, asserts that the human population plunged to 5,000 to 10,000 individuals — implying that we nearly went extinct.  Others point out that there is no evidence of extinction spasms among mammals at this time.  It’s not easy being an expert on days long past.

Anyway, Stringer suggests that if a similar eruption had happened closer to Africa, instead of Sumatra, it could have been game over for our species, but maybe not Neanderthals, who resided north of Africa.  Or, today might look very different if the rollercoaster of ice ages had occurred in a slightly different pattern over the last 200,000 years.  The outcome could have easily been quite different.  Chance is powerful juju.  Stringer is not a member of the progress cult.  He believes that our long-term future is entirely unpredictable.   I agree.

Sunday, June 4, 2017

Hunting Strategies in Central Europe



Hunter-gatherer cultures differed widely in their dependence on technology.  The persistence hunters of the Kalahari used almost none, while those inhabiting cold regions required huge survival toolboxes — weatherproof shelters, warm hearths, fur clothing, canoes, specialized weaponry, food storage.  In the far north, hunting clans also required dozens of large sled dogs, and feeding them required killing many additional wild animals, all year long.  The utterly simple Kalahari way of life was practiced by our hominid ancestors for two or three million years.  These tropical primates had coevolved with their tropical ecosystem, and elegantly danced to the beat of the land, a vital key for their long-term success.

I was curious to learn more about the hunting cultures of my prehistoric ancestors in snowy Europe, so I plowed through a pile of scholarly books, papers, and websites.  The Stránská skála site near Brno, Czech Republic looked promising.  It held the remains of bison, horses, mammoths, elk, rhinos, bears, and giant deer.  I came across Hunting Strategies in Central Europe During the Last Glacial Maximum, by Dixie West.  Most of the book focused on stone tools and bone fragments found at Stránská skála and another site.  I didn’t find what I was looking for, but the info I found was important for better understanding this chapter of the human saga.

The Last Glacial Maximum (LGM) was the frigid peak of the last ice age, which occurred between 20,000 to 15,000 years ago.  Glaciers retained so much water that sea levels were 410 feet (125 m) lower than today.  A lass could walk from Ireland to Scandinavia or France without getting her feet wet (MAP).  During the LGM, climate became cooler and more arid, which had a serious impact on vegetation, and the animals that depended on it.  Many species that had survived a number of earlier ice ages began to go extinct.  Climate was an important actor in this drama.  Notably, highly skilled human hunters, with state of the art technology, were now well-established residents of Europa.

Once upon a time, mammoth country ranged from Western Europe to Alaska, New England, and Mexico.  Mammoths needed to stay close to water.  Because they were huge, and moved slowly, they couldn’t utilize sparse scattered patches of vegetation, or food too distant from water sources.  Difficult terrain was also off limits for the huge critters.  Each day, an adult needed to eat 440 to 660 pounds (200 – 300 kg) of moist feed, preferably grass.  A horse could get by on 22 pounds (10 kg) per day.

Frozen mammoths have been found, and their guts contained larch, birch, willow, sedge, mosses, and grasses.  They were able to digest both low fiber fresh grasses and high fiber wood, and quickly convert them into mammoth poop.  As the climate became cooler and more arid, their food supply diminished.  European mammoths were stressed by 24,000 years ago.  As the harsh climate intensified, the slow-moving animals had to migrate to warmer regions, which were already occupied by other large herbivores.

In a dryer climate, vegetation became more fibrous, or went dormant.  Seasonal bottlenecks in the food supply for grazing animals increased.  Bison, aurochs (cattle), sheep, and goats digest their preferred food slowly, and a diet higher in fiber would have been a threat to survival, in the driest periods.  They joined the mammoths in drifting toward greener pastures.

Similarly, reindeer had a limited ability to digest cellulose, but they were able to survive because they could quickly travel long distances each day, selectively dining at smaller patches of the most nutritious food.  Another plus was their ability to digest forages that other species could not, like lichens.

Horses were also lucky, because they could thrive on a high fiber, low protein diet.  They had to spend more time grazing on lower quality food, consume larger amounts of it, and expand the size of the territory they grazed.

The LGM made life more challenging for hunters.  Game animals declined in numbers and variety, so more time was spent searching for them.  The lads preferred to take larger animals that provided generous amounts of meat, body fat, marrow, and bone grease.  Fat was very important.  When a carcass provided little fat, more meat had to be consumed to acquire necessary nutrients.  West noted, “If fat is totally absent in the diet, very lean meat should be avoided as it takes a higher metabolism to digest purely lean meat, and predators, including humans, can readily lose weight on a lean meat diet.”

At the kill site, animals were often dismembered, making it easier to haul them back to camp.  They hauled away the prime stuff, and left behind low quality stuff for scavengers to enjoy and recycle.  Marrow was prized, and reindeer bones contained a lot of it.  Horses were twice the size of reindeer, but the deer had 13 times more marrow.  Horses provided lots of protein, but had minimal body fat or marrow.  It wasn’t worth the effort to haul away horse bones and break them apart at camp.

There were two types of horse groups, harems and bachelor herds.  The dominant stallion protected his harem of mares, and the young colts.  Colts were prime targets for predators, but stallions were big, strong, and aggressive — kicking, biting, and stomping all threats.  When hunters attacked a harem, the stallion had to be killed first.  Hunters were less likely to die when attacking bachelors, but less likely to get meat, because bachelors rapidly dispersed in every direction.

For ambush hunting, waterholes were a prime location.  Hunters waited, concealed in blinds.  As the LGM squeezed plant communities, horse herds were forced to scatter more for grazing, making them harder for hunters to find.  During fall and spring migrations, herds could swell to thousands of animals.  They were fattest in the late autumn.  Hunters could kill many by driving them into box canyons, ravines, stone corrals, and other traps.

Reindeer also gathered in large herds for seasonal migrations.  Autumn was the prime season for hunting.  Reindeer were much easier to kill, but these smaller animals provided less protein.  Hunters consumed their meat, blood, fat, marrow, and the milk of (killed) lactating cows.  West adds, “Modern caribou hunters provide evidence that ancient humans could have relied on partially digested gut contents and feces of reindeer to fulfill nutritional requirements.”  Yum!

Antlers were used to make tools.  They could be eaten while in summer velvet.  Fat was burned for light.  After the hunt, hides were prepared for tanning, and meat was butchered for drying or smoking.  Bones were broken to get marrow, and then crushed and boiled to extract the bone grease.  Containers were made from hides, bladders, and guts.  Cordage was made from tendons and sinews.  Hides were used to make blankets, boots, and clothing.

Caribou are close relatives of reindeer.  Each year, 24 hides were needed to maintain a caribou hunter’s wardrobe.  At least 20 hides were needed to make a tent.  Boiled hides were famine food.  From time to time, when adequate vegetation became scarce, the routes of seasonal migrations might change suddenly without warning.  It only took a few weeks for a hunting group to die from starvation.

For me, the moral of this story is that life is vastly easier when tropical primates remain in their tropical motherland, and live as their ancestors had for several million years, relying on a few very simple tools.  Migrating into non-tropical ecosystems, like Europe, demanded serious technological innovation, a dark juju that proceeds slowly at first, gradually accelerates, and then explodes.  Innovation is highly contagious, demonically addictive, and phenomenally destructive in its advanced stages.  Old-fashioned cultures that wisely nurtured voluntary restraint and simple lifestyles were helpless deer in the headlights of runaway innovation, forcing them to leap aboard the Oblivion Express or die.

In her book, The Old Way, Elizabeth Marshall Thomas reported that the traditional Kalahari way of life is over.  Clever lads discovered that enslaved dogs made tracking and hunting much easier.  Later they got enslaved horses, eliminating the need for long distance running.  Then they got guns, which were far deadlier than bows and arrows.  Progress never sleeps.  Guess what happened to the game.  Only a few elders still remember the art of tracking, a million years of time-proven knowledge.

Year after year, we’ve been zooming past countless red warning signs.  Wrong way!  Do not enter!  The path of human-centered thinking is approaching its clearly marked dead end.  Beliefs, spells, and madness got us into this mess — not genes.  Devastating epidemics of status fever are spread via stupid ideas.  Sane ideas are an effective cure.  Imagine that.

West, Dixie, Hunting Strategies in Central Europe During the Last Glacial Maximum, British Archaeological Reports, Oxford, 1997.

Thomas, Elizabeth Marshall, The Old Way: A Story of the First People, Farrar Straus Giroux, New York, 2006.

Woolly mammoth image above (source).

Sunday, September 4, 2016

The Call of Distant Mammoths




I’ve long been interested in the megafauna extinctions of Pleistocene North America.  A number of books endorse Paul Martin’s “Pleistocene Overkill Hypothesis,” which asserts that the early humans on the continent were “super predators” who launched a blitzkrieg of overhunting.  Hunting began in northwest Canada, and spread south and east like a wild fire.  Within 2,000 years, at least 33 genera (50 species) of large mammals went extinct — many more than in the preceding three million years.  At first contact, large animals who had never before seen odd-looking humans, did not sense danger.

In other locations, when humans first arrived, extinctions followed — for example, Australia, New Zealand, Madagascar, and Caribbean islands.  Hunting, and hunting alone, was the cause, said Martin.  His ideas really pissed off Native Americans, like Vine Deloria, because overkill implied that Indians were as foolish as Euro Americans.

Deloria blasted the hypothesis, pointing to the fantastic number of bones found in northern Siberia — mammoths, mastodons, rhinos, horses, bison.  Chinese have been hauling away mammoth tusks since medieval times, and this ivory is still being mined today; a high-quality tusk can fetch over $40,000.  The white keys on grandma’s piano might be mammoth ivory.

These bones were not the result of a blitzkrieg.  Mastodons had been living in Siberia for 400,000 years, and woolly mammoths for 250,000 years.  The frigid climate helped to preserve their remains.  In central Russia, more than 70 mammoth bone huts have been found.  One hut had 385 bones, and weighed 20 tons.

I just read The Call of Distant Mammoths by paleontologist Peter Ward, and learned a lot about extinction and evolution.  I’ve often wondered how hairy lads, on foot, with wooden spears, were able to exterminate every horse in all of North America within 2,000 years.  Bison were also residents of the open plains, able to sprint up to 35 miles per hour, and they did not go extinct — and horses could run even faster.

Ward introduces us to the climate change hypothesis.  During the two million year Ice Age (the Pleistocene), there were at least 18 glaciation cycles.  Until the last cycle, the megafauna had mostly survived.  The last one began 18,000 years ago, and it was the most intense of all.  It ended 12,000 years ago.  The ice pack melted, forest advanced, and habitats rapidly changed.  The mammoth tundra fragmented and shrank, which split the herbivore population into isolated groups.

Ward also studied the extinction of dinosaurs.  They roamed the Earth for 160 million years, and then disappeared.  Ward was an early advocate of the notion that the dinosaur mass extinction was sudden, caused by an asteroid strike near Chicxulub, Mexico.  Some say it resulted in a decade of near-freezing temperatures on a planet that was largely tropical.

Throughout the dinosaur era, small mammals also existed — insect eating night creatures.  The extinction of dinosaurs eliminated large animals, and made the age of mammals possible.  If not for the asteroid, humans and elephants would have never evolved.  Mammoth country once ranged from France to Siberia to New York.

Our primate ancestors evolved in the trees.  Their tropical homeland was eventually chilled by an era of glaciation.  It thinned the rainforest, and expanded savannahs, which encouraged the evolution of large mammals, including our hominid ancestors.  Thus, you and I are the children of climate change and asteroids.

Evolution is a process that creates and deletes species.  New species can only emerge when a group becomes isolated, evolves unique traits, and eventually becomes unable to interbreed with their old kin.  Homo sapiens come in many sizes, shapes, and colors, but all belong to the same species, because we can all interbreed.  Ward expects white skinned people to disappear in a few thousand years, because of their increasing vulnerability to skin cancer.

Our cultural myths tell us that humans are continuously getting smarter.  Ward believes that the brains of modern humans are essentially the same as the first Homo sapiens in Africa, 125,000 to 200,000 years ago (but we’ve learned lots of stuff since then).  Once a new species emerges, it changes little thereafter.  Humans are the last species of the hominids, and this has risks.  A gene pool has better odds for long-term survival when it diversifies into multiple species, as the ants have.

Another way for critters to avoid extinction is to become generalists, like humans, rats, and cockroaches, who have adapted to many different ecosystems around the world.  Today, humans live everywhere.  There is no place a group could remain isolated for millennia.  So, there is little chance for a new hominid species to emerge.

Evolution is random, like tossing dice.  The process is influenced by ongoing environmental change, natural selection, and genetic drift (chance genetic changes).  Evolution has no foresight; it can’t anticipate coming changes.  It’s not always progressive.  Greenland ice core data tells us that there have been times when global temperature changed up to 18°F in a few decades.  Many gene pools that work well in one set of conditions will fail to adapt to sudden shifts.

The golden rule of evolution is adapt or die.  Ward doesn’t discuss cultural evolution, which is a million times faster than genetic evolution, and has catapulted humankind onto extremely thin ice, by overloading our tropical primate brains with way too many half-smart ideas.  We are, by far, the world champion resource parasites.  We are hurling countless species into the abyss in our insane impossible quest for perpetual economic growth.

In an extremely quirky twist, Ward celebrates human supremacy at causing mass extinction.  “We are the comet now.  And not only have we won the game of evolution; we control the rules of the game,” he wrote.  “And to this winner, in my view, goes an even greater prize: species immortality.  It is my opinion that no matter where on the board we humans land and no matter what card we draw, we cannot be knocked into extinction.”  Who could disagree?

The book was written 20 years ago, when resource limits and climate change were still dumb ideas among the lunatic fringe — rational people.  Ward is employed in academia, which remains a militant hotbed of radicalized human supremacists.

OK, back to the megafauna.  Doubts are growing about the overkill hypothesis.  Martin claimed a sudden 2,000-year rampage wiped out the megafauna, but this was based on data generated by obsolete dating technology.  Improved dating does not confirm sudden extinction.  Martin claimed the extinctions fanned out in a wave, beginning in Alberta — so kill sites far from there should be more recent.  They aren’t.  We have only discovered a dozen sites where human artifacts are found with mammoth remains.

Dan Fisher has studied of mammoth tusks in Michigan and Ohio.  Tusks have annual rings inside, like tree trunks.  Rings are thin in hungry years.  In female tusks, rings mark each pregnancy, providing a birth rate.  If climate change had killed the mammoths, the rings would indicate malnutrition, but Fisher found that the last mammoths were “fat, fit, and well fed.”

Ward suspects that the mammoths were the victims of hunting.  Unlike bunnies, mammoths were slow to mature, and had low reproduction rates.  If hunters had regularly taken just two percent of the animals each year, the extinction process would have taken 400 years — too slow for each generation of hunters to notice.  Hunting alone could have wiped them out.  Ward thinks that if there had been no hunting, mammoths would probably have survived the warming climate.

In the 1990s, editors adamantly insisted that manuscripts like Ward’s include brilliant solutions and happy endings, because bummer books didn’t sell.  So, his mammoth book ends with a happy visit to the year 3001.  Population was well below its peak of 11 billion.  The U.S. grain belt was a desert.  African survivors were healthy vegetarians with solar panels and pedal-powered transport.  The rainforest was long gone, replaced with endless fields of GMO crops.  Wildlife and livestock had been eliminated by starving hordes.  Happily, the human species survived — hooray!

Compulsory happy endings meant that vital knowledge was deliberately withheld from an entire generation, who are now teachers, reporters, and leaders.  Even today, a “don’t frighten the children” strategy remains common among educators, and young minds are still being infected with a carcinogenic worldview.  Bummer!

Ward, Peter D., The Call of Distant Mammoths, Copernicus, New York, 1997.