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.