Megafauna is an important, fascinating, unforgettable,
one-of-a-kind book. It primarily focuses
on prehistoric megafauna extinctions around the world, and how they
happened. Baz Edmeades (“ed-meedz”) has
been working on this book for 20+ years, and it is impressively thorough. His grandfather was a professor who found a
unique human-like skull that was about 259,000 years old.
Megafauna are mammals weighing more than 100 pounds (46
kg). Hominins are primates that walk on
two legs, like you and I. Hominins have been
around for several million years. Humans
have been around for 250,000 to 400,000 years, depending on who you ask.
During the last two or three million years, lots of megafauna
species, all around the world, have moved off the stage forever. Why? A
heated debate has been buzzing for 50+ years.
Was it an asteroid strike? No
evidence. Were they zapped by
diseases? No evidence. Was it climate change? It probably strained some regional
situations. Was it human activities? The evidence strongly supports this. In 1966, Paul Martin presented his megafauna
overkill theory (humans did it), which ignited big controversy in
academia. Edmeades became friends with
Paul Martin, and learned a lot from him.
Hominins originated in Mother Africa, where there used to be
at least nine species of big cats (three today), nine types of elephants (one
today), and four hippos (one today).
There were giant antelopes, giant hyenas, giant pigs, giant monkeys, and
giant baboons — all gone. Extinction
spasms especially surged as humans wandered out of Africa, and gradually
colonized the planet. They migrated
across Southern Asia, to Australia, then Eurasia, and finally the Americas.
Paul Martin coined the misleading term “blitzkrieg overkill,”
which angered quite a few folks. As
humans colonized new regions, the megafauna declined in number, in a process
that could take a thousand years or more, multiple generations. It was not a high-speed massacre. These hunters were Stone Age people, using
simple tools. Many of the large game
they hunted had low reproductive rates, which made them extremely vulnerable to
extinction.
There is a clear pattern that when hunters migrated into
continental land masses, stuff went extinct — except on uninhabited
(human-free) offshore islands of the Mediterranean, Caribbean, and
elsewhere. On these islands, extinctions
didn’t begin until humans eventually stepped ashore, sometimes thousands of
years later. Understand that offshore
islands have a climate quite similar to the nearby mainland. Climate was not a factor here. Many of the megafauna species that blinked
out had survived multiple ice ages over the passage of several million years.
In 2015, I stumbled across early sections of the Edmeades
book online, and they blindsided me. I
never understood how incredibly alive this planet once was, and how tragically
damaged it now is. None of my teachers
ever explained this, because they never learned it. Our cultural myths celebrate the upward
spiral of humankind’s brilliant achievements.
We live in a technological wonderland, not an ecological graveyard. Life has never been better, and the best is
yet to come.
The ancestors of hominins were originally tree dwellers. Our closest living relatives are chimps, with
whom we share 98.8 percent of our DNA.
Long ago, when the climate changed, and forests shrank, our ancestors
were forced to survive as ground dwellers, a lifestyle for which evolution had
not prepared them.
Over the course of several billion years, evolution has been
a remarkable force that guided the journey of the family of life. When frigid eras arrived, critters evolved
fur coats. When foxes became faster,
evolution selected for faster bunnies.
It was a balancing act. Foxes
needed bunnies, and bunnies needed foxes.
The family of life was continuously fine-tuned at the speed of
evolution, an extremely slow process.
Alterations could take many thousands of years.
Over millions of years, evolution provided giant tortoises
with large bodies, invincible lion-proof shells, and long lifespans. In the blink of an eye, these advantages were
rubbished when hominins moved into the neighborhood, and began killing 200-year-old tortoises with big rocks. This
hunting method was not fine-tuned by evolution.
It was a sudden innovation that popped into the mind of a hungry hominin
— and it worked! Invincible tortoises
were immediately transformed into helpless sitting ducks that didn’t have a
bright future. Evolution was yanked out
of the driver’s seat. Ancient rules no
longer mattered.
Hominin cleverness changed the world. It made it far easier to grab essential
resources, grow in numbers, and avoid becoming cat food. Cleverness had the long term impact of an
asteroid strike. Cleverness enabled hominins
to domesticate fire, plants, and animals.
We colonized the planet, developed industrial civilization, zapped the
forests, polluted everything, and destabilized the climate.
Many folks in the human herd suffer from a blind faith that
the miraculous power of cleverness can easily overcome all challenges. Their vision is to keep our maximum impact
way of life on life support, as long as possible, and hope for the best. Edmeades presents no solutions, but this is a
story that was important to tell. He
laments that cleverness “has given our species the power to transform the
biosphere so profoundly that no other organism on this planet may get the
opportunity of evolving it again.”
His book does an excellent job of discussing the megafauna
extinctions in an understandable way, with up-to-date information. Its bitter medicine, and good medicine. Many misperceive evolution to be a divine
competition, in which species fight relentlessly to reach the top of the
hierarchy, seeking to wear the Dominant Animal crown. This pyramid-climbing quest for domination is
the engine of civilization. By the end
of the book, you understand that evolution is more about adapting to changing conditions
in a way that is as smooth and balanced as possible.
Evolution has been the great friend of the family of
life. The Dominant Animal game has been
its grim reaper. While the wild
megafauna are now sharply diminished, human-caused extinctions of many other
species continue at an accelerating rate.
Cleverness never sleeps. I’ve
spent 69 years in a roaring hurricane of devastating cleverness. Edmeades book reminded me that this planet
was once a healthy and amazing living paradise.
Some of my genes have their roots in those good old days of abundant
life. That’s a comforting notion.
Edmeades, Baz, Megafauna: First Victims of the
Human-Caused Extinction, Houndstooth Press, 2021.
