We all know extinctions are bad—but extinctions aren't a yes or no question, they're a spectrum. That's why we need to understand the idea of 'defaunation,' a term coined by today's guest, legendary conservation scientist Rodolfo Dirzo.

Support the show by checking out these Black Friday Deals: ZBiotics (Decrease impact of hangovers. Code: JESSEDAMIANI for 10% off), MUD\WTR (50% off starter kits), 1Password (simplify your life and increase digital safety), Mission Farms CBD (healthy, effective CBD for relief, sleep, and wellbeing—40% by using the code found at that link), NordVPN (the simplest way to protect yourself online, 74% off 2-year plans).

A few months ago, I hosted Gerardo Ceballos and Paul R. Ehrlich, two of the authors of Before They Vanish—a book outlining why biodiversity is so critical to life on Earth, how it’s imperiled, and what we can do about it. I had originally hoped to have all 3 authors in the mix, but one of them—Rodolfo Dirzo—was, fittingly, out in the field. Fortunately, we were able to get some time to chat after he’d returned. We spoke extensively about his background in ecology, the tragedy of biodiversity loss, and in particular: defaunation. It’s a term he coined to describe the loss of animals (fauna) across all the various forms that can take: ranging from extinction and extirpation to local population declines. You’re probably familiar with the term “deforestation”—think of defaunation as a sort of counterpart.

As a lover of words, I think having the right word for the concept is critical in communicating necessary ideas. In this case, defaunation gives us a means to understand animal loss on a spectrum. Think of it this way. Even though a species might not have been totally eradicated, a dramatic drop in its numbers might have a whole host of knock-on effects, throwing an ecosystem out of whack. If our only metric for “caring” about animal populations and biodiversity is extinction, we’re missing critical danger signs that an ecosystem has been imperiled. Defaunation, then, allows us to understand the notion of animal loss in a more ecological sense—and measure for it.

CREDITS: This podcast is edited and produced by Adam Labrie and me, Jesse Damiani. Adam Labrie also directed, shot, and edited the video version of the podcast, which is available on YouTube. The podcast is presented by Reality Studies. If you appreciate the work I’m doing, please subscribe and share it with someone you think would enjoy it.

Find video episodes of Urgent Futures at: youtube.com/@UrgentFutures.