Can you imagine childhood without dinosaurs? I can’t. What did three year-olds do before there were books of dinosaurs to pour over? How did they learn to pronounce multisyllabic words in the absence of archaeopteryx, velociraptor, and tyrannosaurus? Were they forced to study German? Maybe this is why young children in pre-twentieth-century novels always seem so developmentally stunted.

My favorite chapter in Elizabeth Kolbert’s The Sixth Extinction: An Unnatural History is the one called “The Mastodon’s Molars.” Though it is about intellectual history more than about dinosaurs, this chapter narrates the transatlantic hoo-hah that ensued when settlers in the American Midwest started turning up huge femurs and teeth on their land in the late 18^th century. At the time, the concept of extinction had not even been considered. “Aristotle wrote a ten-book History of Animals without ever considering the possibility that animals actually had a history” (23), Kolbert writes, while “Pliny’s Natural History includes descriptions of animals that are real and animals that are fabulous, but no descriptions of animals that are extinct” (23-24). Like so much else in science, the idea that species of animals could exist at one time and then disappear came into conflict with religious teachings. The idea of extinction seemed heretical – as if it suggested that God had made terrible mistakes and needed a do-over. If occasionally a freethinking scientist came to the conclusion that God actually had made terrible mistakes and needed a do-over, he could easily rely on the story of Noah and the ark – and indeed for centuries naturalists explained away fossils and other traces of unfamiliar life forms using this story and the many flood myths in other cultures. A tooth from an animal unlike any known creature on earth was simply a relic from a species that didn’t survive the flood.

Of course, extinction is troubling even if one is capable of separating science and religion – since the existence of extinct species begs the question that we ourselves might someday become extinct. One of the key themes in 18^th- and 19^th-century thought, in Western culture anyway, is the idea that randomness plays a greater role in the natural world than medieval and early modern thinkers ever imagined, and Judeo-Christian philosophy has always taught that God has special plans for human beings. Much of modern science discredits this idea, by (to name just one example) suggesting that someday our species might be all gone and creatures like none we’ve ever known will be pulling our bones and teeth from graphite mines and struggling to place them into their own taxonomies.

Kolbert’s book, however, is not about dinosaurs. It’s about the extinctions that are underway in the world today. Each chapter in this book highlights one extinct or almost-extinct species or genus, explains how or why it became extinct (or is currently becoming extinct). The book’s primary thesis, of course, is that the wave of extinctions that began tens of thousands of years ago with the Neanderthals and continues today with rhinos, frogs, and corals is caused by the actions of human beings. The idea that human beings have done damage to the earth is not new, but most discussions of the subject begin with the Industrial Revolution. We mythologize the pre-industrial past, believing that sure, medieval cities were a little gross, but overall human life was pastoral and gentle in its relation to the land. To the contrary, Kolbert writes in detail about the kooky French scientist named Cuvier who was the first to argue (correctly) that the earth has undergone several cataclysms over the course of its history, one of which we now know to be the asteroid collision that killed off the dinosaurs. In his study of the bones of dinosaurs and other extinct creatures like mammoths and mastodons, Cuvier predicted that the most recent such cataclysm took place “just beyond the edge of recorded history” (45) – and Kolbert makes the connection that it is the unconscious memory of that cataclysm that led  nearly every culture on earth to develop its own flood myth. In the haunting final paragraph of the second chapter of her book, Kolbert writes: “The American mastodon vanished around thirteen thousand years ago. Its demise was part of a wave of disappearances that has come to be known as the megafauna extinction. This wave coincided with the spread of modern humans and, increasingly, is understood to have been a result of it. In this sense, the crisis Cuvier discerned just beyond the edge of recorded history was us” (46) – meaning that even in our hunter-gatherer years we were already killing off the species with which we shared the planet.

dum dum DUM.

I’ll stay away from a lengthy treatment of the chapters that follow, except to say that Kolbert traveled all over the world with researchers and did more foraging around in the dark for frogs and bats and such than I have ever done – and I admire her meticulous research and her accessible, often-humorous prose. My own interests are anthropological rather than zoological, and I will admit that I was not the best of students during the coral reef chapter. Overall, though, I enjoyed the book very much. After the chapter on Cuvier and the dinosaurs, my favorite chapter was the one on Neanderthals, who were, genetically speaking, Homo sapiens’ closest relative. Kolbert is very good at pointing out the ironies of evolutionary history, including the following: “Somewhere in our DNA must lie the key mutation (or, more probably, mutations) that set us apart – the mutations that make us the sort of creature that could wipe out its nearest relative, then dig up its bones and reassemble its genome” (240).

Even if you’re not as interested in Neanderthals as I am, this chapter is worth a read if only for the fact that it contains this picture, which is a simulation of what a Neanderthal man would look like if he dressed in modern clothes:

I can’t stop looking at this picture. What is that in his hand – a stone tool? A candy bar? I had hoped to tell you that Google-imaging “Neanderthals dressed in modern clothes” would lead to a wealth of hilarity, but unfortunately, that was not to be. That Google search only leads to a handful of photos of this same guy, plus lots and lots of photos of Jon Snow from Game of Thrones.

The Sixth Extinction is a great read for the non-scientist who wants to keep tabs on how our understanding of the earth is developing and changing. Part history, part biology, part ecology, and part philosophy, Kolbert’s book entertains and instructs, pointing out the Neanderthal’s resemblance to Yogi Berra in one breath while in the next delivering knockout punches like the fact that all amphibians currently face extinction. All of them. Did you know that? I didn’t know that. My only small quibble is that Kolbert never questions her use of the word “unnatural” in the title. I don’t doubt a single case she cites in which Homo sapiens has out-competed or downright slaughtered its fellow creatures in the past thirteen thousand years. However, I have trouble with the idea that this is somehow “unnatural.” From a scientific perspective, we came about our enlarged cerebral cortexes, our opposable thumbs, our descended larynxes, and the other anatomical and behavioral characteristics that helped us to thrive in the same way other species arrived at theirs: through natural selection. Now that we understand how evolution works, it’s true that human beings can and sometimes do attempt to manipulate it for their own ends, with “designer babies” and so forth – but for most of human history we had no idea that we were subject to this slow, invisible process. As I see it, Homo sapiens may have won the evolutionary lottery, but there is nothing “unnatural” about how it did so. I know that this is a contested subject, and that Kolbert may in fact believe that human dominance of the natural world is somehow “unnatural”; I just wish she had engaged with the subject instead of taking it as a given.