Image from https://en.wikipedia.org/wiki/Holocene_extinction, labeled as "Free to use and share."
The Sixth Extinction: An Unnatural History was first added to my summer reading list as one of the potential book reads for Horizontal Transfer podcast listeners. It didn't make the cut for that particular group, but after listening to an interview with the author, Elizabeth Kolbert, on an MPR podcast a few weeks ago, I decided to read it anyway. She captured me with her descriptions of the book that made it seem one part adventure and one part natural history. The book did not disappoint in this regard, however I feel that the science stories it shared were more suited to new-comers to the topic.
Much of the book involves Kolbert traveling all over the world in order to experience unique ecosystems, locate a rare species, or visit the site of a historic event. She starts the book with a few chapters on endangered or extinct species and their connection to the mass extinction events of the past and present. A trip to Panama examines the current rapid decline in amphibian populations, and chapters about mastadon fossils and great auks take the reader through the history of scientific thought about extinction. The discovery of the KT-Boundary and its associated "bolide" impact is explained through the use of ammonite fossils.
The second half of the book reveals more specifically how humans are directly linked to the current mass extinction event, or the "Sixth Extinction." In these chapters, Kolbert travels to Scotland, the Tyrrhenian Sea off the coast of Italy, the Great Barrier Reef, the Andes Mountains in Peru, the Brazilian Amazon, New York, and Cincinnati to focus in on the major human impacts on global extinction: ocean acidification, deforestation, and the transportation of invasive species. Again, she scaffolds these chapters with stories of particular species, such as the little brown bats that are dying from white nose syndrome and a Sumatran rhino a zoo is attempting to breed in captivity. She even spends a chapter on Neanderthals and their possible extinction as a result of interactions with H. sapiens.
Kolbert does not end The Sixth Extinction with her prescription of "how to make it all better." We are in the midst of a mass extinction, and righting the ship at this point may be out of our hands. She outlines that there are two possibilities here: Number One, humans continue to impact the Earth in a way that eventually leads to our own extinction. The Earth will continue into the future, less diverse but still teeming with life; we just won't be a part of that. Possibility Number Two, our creativity and innovation will allow humans to explore and settle in different worlds. Most importantly, Kolbert makes clear that up until this point, we have been causing extinctions without truly understanding their impacts. Now that we have a better understanding of extinction, biodiversity, and evolution, we need to be more thoughtful about the choices we're making that affect the biosphere.
I have to admit I found myself wishing to visit some of the places Kolbert describes, especially considering many ecosystems are disappearing (the Great Barrier Reef may be gone in 50 years). However, can I justify that type of travel when so many extinctions are directly or indirectly related to climate change? Not really. Other than enjoying Kolbert's descriptions of these amazing ecosystems and species, I can't say this book offered me a lot of new scientific information. Many of these case studies have been covered pretty thoroughly in the news. In fact, a few days ago, I ran across this recent study supporting that we are indeed in the midst of a mass extinction event. I agree with Kolbert in that humans, in general, need to become more aware of the impact of our actions on other species. This is where my role as a science teacher comes into play. Though I am pretty familiar with the science in her book, my students are not. I have the resources and time to educate students about these pressing issues. In summary, I didn't learn much new information by reading The Sixth Extinction, but I will definitely share excerpts from the book with my students.