Why this book:
Elizabeth Kolbert has been on my radar since the fall of 2011 when her New Yorker article on Human/Neanderthal hybridization–a topic she returns to in the book at hand–was assigned for my college seminar on global change, the sort of hybrid biology and anthropology class you’d expect at any halfway respectable liberal arts school in the Northeast. At the time, I wouldn’t have classified the article as a profound moment in my career development. In hindsight, however, this was the first time I was introduced to the concept of admixture. This word would eventually become so integrated into my vocabulary that I’d forget it wasn’t “normal” to use it conversationally. I went on to study inter-species hybridization during my Ph.D., which at the genetic level leads to “admixed” offspring with genes from both parent species, precisely the phenomenon Kolbert describes in Neanderthals and humans.
The following year of my undergrad, Kolbert’s first book from 2006, Field Notes from a Catastrophe, was assigned for my science writing course, and my enthusiasm for Kolbert’s work faltered. I admit to having no specific memories of the book thinking back to spring 2013, but I recall being excited to read it, and then felt somewhat blah about it. The Sixth Extinction was published in 2014, won the Pulitzer in 2015, and has been sitting on my bookshelf since 2016. For a brief period, I even had two copies of it. I made one previous attempt to read it, but due to the ever-present “grad student burnout,” I didn’t get beyond the first chapter.
Mindset going in:
I have controversial opinions on wildlife conservation. Or, to phrase it more diplomatically, I enjoy spirited and intellectually challenging conversations with conservation biologists.
For example, in reference to controversies related to invasive species, I may ask how long a species must be established in a particular area before it can be considered native. Then, depending on the answer, I might ask if all species that have expanded their range (i.e., every species that’s ever existed) could be considered invasive at one point in their evolutionary history. Or, if humans are above this distinction even though our species evolved in Africa and expanded elsewhere. What the term “natural” even means. And so on.
To be clear, I am not at all anti-conservation. But I do believe that conservation approaches should be rooted in ecological and evolutionary principles rather than emotional connections to wildlife, which are all too easy to get caught up with.
How the book stacked up:
While I was genuinely interested in what Kolbert had to say about human-driven biodiversity declines, I was also concerned that the book might lean towards the emotional and call on the decline of charismatic megafauna to tug at the heartstrings of readers. This perception wasn’t entirely wrong. There is a chapter on Suci, the resident female Sumatran Rhino at the Cincinnati Zoo, and the unsuccessful attempts to get her pregnant through artificial insemination. Most of the book, however, dealt with plenty of less charismatic species, many of which I had not previously heard of. These species included those that are long-extinct (graptolites from the Ordovician), those recently departed (Great Auks from the 19th century), and those declining right before our eyes (Acropora corals of the Great Barrier reef).
Though deconstructing the argument is beyond the scope of this blog post, Kolbert does provide an answer to one of my go-to questions for conservation biologists: Why is the involvement of humans in the decline of other species fundamentally different from the other ecological interactions that may lead to biodiversity decline?
For Kolbert, it’s a two-part answer: speed and scope. To illustrate this point, Kolbert first calls on the example of the spread of the deadly chytrid fungus in frogs in Central America. Although humans didn’t directly cause the fungus (it evolved in the usual way), humans have spread it across the globe at an unprecedented rate as an indirect result of other activities. Kolbert argues that in a world without widespread and rapid human activities, deadly diseases would still inevitably evolve. The total global impact on biodiversity, however, would be less severe, as infections are far more likely to remain geographically restricted and spread at a much slower rate. This same sentiment is also echoed later in the book with the rapid spread of the similarly devastating white-nose syndrome in bats. It is then further extended to other examples of the indirect consequences of human activities, such as ocean acidification, over-hunting, and so on.
In summary, according to Kolbert, human-driven biodiversity decline is fundamentally different from other ecological forces because it occurs more quickly and over more extensive geographic areas. Species simply don’t have the opportunity to adapt to the changing conditions.
An inevitable reoccurring theme in popular science writing is that it’s tough to tell compelling science stories to general or even specialist audiences. I love science, and I still find myself occasionally bored by science writing (see above comment about Kolbert’s first book). The Sixth Extinction, however, was an impressive comeback. The one-species per chapter format helped to create a sense of novelty every 15 or so pages, and I never felt fatigued reading about the same thing for too long. While I’m not about to stop having spirited conversations with those who work directly in applied conservation, Kolbert’s eloquent perspective on the scale and scope of human-driven biodiversity decline was well-received.