[Note: This is the fifteenth 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.]
Smashing
Limits
Fearless prey was a lucky but temporary windfall jackpot for
migrating hominins. Another major asset
was our ability to digest a highly diverse diet of plant and animal
substances. Because we aren’t fussy
eaters, we can survive changing conditions better than many other species. This advantage was greatly expanded by our
unique ability to cook foods. We can
nourish ourselves in chilly Greenland, steamy Amazon rainforests, and the
scorching Sahara. In recent times,
humans have also become the top carnivore in marine ecosystems, despite the
fact that we don’t even live in the water.
Over the span of millions of years, animal species of all
types and sizes evolved time-proven anti-predator strategies for self-defense —
flying, fleeing, swimming, climbing trees, diving into burrows, injecting
venom, counterattack, camouflage, and so on.
These ancient strategies worked fairly well, but not every time. Predators needed sustenance too. Ideally, predators and prey lived in relative
balance. This encouraged wild ecosystems
to maintain a state of long term sustainability. Perfect!
It discouraged population explosions that can become ecological
hurricanes. Hooray!
When musk oxen were attacked by wolves, the group backed up
together into a circle, butt to butt, with their horns facing outward, and
patiently waited for the hungry predators to give up and have a good cry. When raccoons, squirrels, or bear cubs were
attacked by predators, they zipped up the nearest tree and giggled at the
frustrated killers. These excellent
time-proven strategies failed when heavily armed hominins arrived with their
deadly projectiles.
For many grassland herbivores, speed was an essential
predator defense strategy. Pronghorn
antelopes can run for more than 20 miles (32 km). They can flee at speeds up to 70 miles per
hour (112 km/h), for up to two miles (3.2 km).
Pronghorns originally evolved high speed flight to outrun hungry cats —
species that went extinct maybe 12,000 years ago. Today, wolves and coyotes are way too
slow. Sadly, ranchers have installed
some fencing on the prairie, and pronghorns can’t leap fences. The fence prevents escape, the animals pile
up, and enable mass kills.
When bison are attacked by natural predators, grazing stops,
and running begins — the whole herd following the leader. Slower animals, like calves, the elderly, and
the sick or injured become the main course at lunch time. This strategy worked well for millions of
years until Neanderthals and humans organized communal hunts, and chose
locations where fleeing herds could be guided into traps or off cliffs. In this situation, follow the leader escapes
could be disastrous.
For eons, sea birds, sea turtles, and marine mammals found
security by living on islands. This
advantage was diminished by the invention of canoes, kayaks, harpoons, and so
on. Many of these island animals lived
in a way that made them highly vulnerable when hungry aliens washed up on
shore. Many had a hard time fleeing or
hiding.
Critters that found security in camouflage or concealment
became far more vulnerable when hominin hunters set fire to the grass. Excellent camouflage lost its advantage when
enslaved dogs joined the hunt. Their
powerful sense of smell enabled them to quickly find prey that were difficult
to see. Critters that evolved the
ability to make high speed escapes became more vulnerable when hunters began
riding enslaved horses. When hunters
used both horses and dogs, game was far less likely to survive.
Evolving to jumbo size was another very effective
anti-predator strategy. Big, strong,
healthy, mature elephants, rhinos, and hippos had little reason to fear wild
carnivores. Size mattered. Predators preferred to kill their youngsters,
because they were less dangerous, and easier to kill. Jumbo size species have far lower rates of
reproduction. Wee critters, like mice,
bunnies, and insects, are popular items on the menus of many animals. Consequently, they reproduce like champions.
Unfortunately, when hominins adapted spear technology, jumbo
size became a serious handicap.
Elephants were big, slow, easy to find, and had lots of meat. Hunting large game was energy efficient. Killing a mammoth required far fewer hours
and calories than killing a thousand bunnies.
Around the world, 50,000 years ago, the land rumbled under the feet of
countless megafauna, every continent a Serengeti.
Stephen Wroe summed it all up. Over millions of years, many animals
developed anti-predator strategies that were good enough to keep their species
in existence. Tragically, the arrival of
tropical primates armed with specialized high-tech hunting technology radically
altered the rules of predation. Advanced
kill power, combined with fearless prey, sparked a revolutionary shift. In the new paradigm, animals had to move
beyond traditional anti-predator strategies, and strive to develop new and
different anti-predator strategies that were hominin-specific. Species unable to make this transition were
more likely to blink out.
Technological crutches enabled our ancestors to become direct
competitors with wolves, big cats, and other carnivores. Wherever hominins expanded, they had the
ability to destabilize long running ecosystem relationships. Crutches also made us less vulnerable to
man-eating predators. Spears enabled our
ancestors to better repel the predators that could help keep hominin
populations stable and healthy. This
rubbished the laws of nature. Imagine
rabbits inventing tools that allowed them to kill foxes — soon there might be
seven billion bunnies staring at cell phones (gasp!).
Colonizing
Snow Country
Obviously, tropical primates evolved to survive in tropical
ecosystems, which were warm all year round.
By and by, some hominins migrated out of tropical regions, and into
temperate ecosystems, which had four seasons, including snow.
When tropical primates began wandering into regions with
frigid winters they were confronted with new and serious challenges to
survival. They were presented with a
painful warning similar to modern highway signs: Wrong Way! Do Not Enter!
But, instead of cautiously turning around, and going back to more
comfortable lands, some proceeded deeper into the domain of the frost giants,
and discovered many super-cool new ways to die prematurely. The game rules radically changed. Warm clothing, protective shelter, new tools,
and food storage boosted the odds for survival.
Outsmarting
Evolution
A bedrock theme in this book is that the ecosystems which
move through the millennia guided by genetic evolution tend to make transitions
in a fairly graceful manner. Ungraceful
ecosystem transitions are far more common when the hominin residents naively
develop a never-ending abusive relationship with the super-sticky tar baby of
cultural evolution and technological innovation.
Japanese snow monkeys slowly and smoothly adapted to a
temperate climate via genetic evolution.
Humans emerged maybe 300,000 years ago, when the hominin drama was
already heavily dependent on cultural evolution (fire, weapons, stone tools,
etc.). Our homeland in Mother Africa had
a tropical climate, and genetic evolution had provided our species with better
heat tolerance. Human genes have not
made extensive changes in 300,000 years.
We remain able to live happily in tropical lands, but still can’t
survive in snow country without a load of prosthetic technology.
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 downward from 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 for the remaining Neanderthals.
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. The ideal weapon for
woodland ambush hunting was the thrusting spear, and it remained the perfect
tool for 400,000+ years.
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. In steppe-tundra habitat, the wide open
landscape had no trees or brush for hunters to hide in. So, their preferred weapon was the javelin,
which could kill from a distance.
When humans wandered into the steppe grasslands of Eastern
Europe 36,000 years ago (the “European Serengeti”), their tropical bodies were
not fine-tuned for freezing weather, nor had they evolved the clever trick of
hibernation. Moving into a winter
wonderland was something like colonizing Mars.
At this point, their choices were: (1) give up and freeze to death, (2)
turn around and return to home sweet home, or (3) innovate like crazy and
struggle to survive in a hostile climate where large game was abundant.
Health
Advantages
Aside from stuff like frostbite, winter hunger, and
respiratory issues from smoke filled shelters, there may have been significant
health benefits to colonizing temperate ecosystems. Our African homeland was tropical, with a
climate that ranged from warm to hot year round. Tropical ecosystems have the highest
biodiversity of plant and animal species, including the entire spectrum from
elephants to microbes. The colder the
ecosystem, the lower the biodiversity, because many species have not evolved
the ability to survive months of intense cold.
Pathogenic tropical parasites include malaria,
schistosomiasis, and sleeping sickness.
Some regions in Africa are uninhabitable due to the high risk of
sleeping sickness. Tropical viral
diseases include yellow fever, and three hemorrhagic fevers: Ebola, Marburg,
and Lassa. A warm climate is also home
to more species of disease transmitting insects, many of which have poor cold
tolerance.
The tropics are home to numerous other species of monkeys and
apes, with whom humans are more likely to swap diseases. For example, AIDS is caused by the HIV virus,
which is probably a mutation of the SIV virus that is carried harmlessly by
chimps. Today, chimps, gorillas, and
humans are dying from Ebola. It is
likely that tropical diseases had far less impact 50,000 years ago, long before
deforestation, bushmeat hunting, agriculture, herding, irrigation, high
mobility, and explosive population growth.
A later chapter will devote more attention to disease.