Wednesday, November 22, 2017

Of course we need to save endangered species: a response

I spend a lot of time thinking about the related topics of conservation, biodiversity, and evolution, so I was interested to see an editorial in the Washington Post on precisely those issues. The article, "We don’t need to save endangered species. Extinction is part of evolution" by Alex Pyron, presents a misrepresentative and potentially harmful position about the future of the earth's biota.

Pyron begins by stating that "Evolution loves death." Selection necessarily means the success of one variant at the expense of others, and today's living creatures are the survivors of an ongoing battle for existence. Extinction is not a modern phenomenon by any means. There have been five mass extinctions, including the glaciation of Gondwana and the impact of an asteroid that lead to the loss of the dinosaurs.

But the 6th great extinction (the Anthropocene extinction - the one we are currently living in) shares little in common with these past events. This is the only extinction that a single species (humans) are primarily responsible for, through activities from habitat conversion or degradation, land fragmentation, warming climate, ocean acidification, and human consumption of natural resources. In this context, Pyron's argument seems to be that we ought to retain an anthropocentric viewpoint of conservation as well. That is, we are simply selecting for species that can survive in our wake, and we should feel concern only for those species that we need.
"But the impulse to conserve for conservation’s sake has taken on an unthinking, unsupported, unnecessary urgency. Extinction is the engine of evolution, the mechanism by which natural selection prunes the poorly adapted and allows the hardiest to flourish. Species constantly go extinct, and every species that is alive today will one day follow suit. There is no such thing as an “endangered species,” except for all species. The only reason we should conserve biodiversity is for ourselves, to create a stable future for human beings. Yes, we have altered the environment and, in doing so, hurt other species. This seems artificial because we, unlike other life forms, use sentience and agriculture and industry. But we are a part of the biosphere just like every other creature, and our actions are just as volitional, their consequences just as natural. Conserving a species we have helped to kill off, but on which we are not directly dependent, serves to discharge our own guilt, but little else."
This is hardly an original viewpoint (hastening to the Bible's 'Then God said, “Let Us make man in Our image, according to Our likeness; let them have dominion over the fish of the sea, over the birds of the air, and over the cattle, over all the earth and over every creeping thing that creeps on the earth.'). But it is a short-sighted one. Ignoring more philosophical arguments about the intrinsic value of all species, the arguments presented are problematic and incomplete, and the potential cost could be huge.

Pyron notes that we may be over-estimating the loss of species:
"According to some studies, it’s not even clear that biodiversity is suffering. The authors of another recent National Academy of Sciences paper point out that species richness has shown no net decline among plants over 100 years across 16,000 sites examined around the world."
The study cited by Pyron here does not support the assertion that biodiversity is fine. In fact, Vellend et al (2013) show that at local scales, plant diversity (i.e., the number of plant species; species number being only way of characterizing biodiversity) has been stable. This isn't the same as saying species are not being lost at a global scale. In a follow-up piece (Vellend et al. 2016), the same author notes that at the global scale, "Nonetheless, if we take 142 and 592 as somewhere in the ballpark of extinctions that have occurred between 1600 and 2016, we get extinction rates of 0.98–4.1, 1–2 orders of magnitude higher than the background rate." Outside of plants, Pimm et al. (2014)'s comprehensive review of extinctions in birds, amphibians, and mammals show extinction rates have at least doubled since 1900. These are rates much higher than considered 'natural'. Even when no extinctions have occurred yet, populations are declining rapidly (Ceballos and Ehrlich 2014, Ceballos et al 2017).

An anthropocentric approach also requires complete understanding and control of our environment. Preventing the loss of the species we need or the ecosystems we rely on is not straightforward (as seen by the rarity with which species become 'non-endangered'). Humans are still under-informed about ecosystem services and goods, and what biotic and abiotic interactions are essential to maintain them. The existence of IPBES is a good indicator of how essential and lacking this information is. To confidently state that "Conserving a species we have helped to kill off, but on which we are not directly dependent, serves to discharge our own guilt, but little else" ignores the indirect linkages that might matter, and our lack of knowledge of them.

Further, the philosophy that humans will survive somehow, in the face of losses of biodiversity and changing planetary climate is probably mostly true for the richest members of the planet. Elsewhere, food shortage associated with climate change (eg.) and water shortages (eg.) already threaten individuals in less wealthy countries.

Ironically, Pyron suggests that all we need to make this reality is "moderation".
"The solution is simple: moderation. While we should feel no remorse about altering our environment, there is no need to clear-cut forests for McMansions on 15-acre plots of crabgrass-blanketed land. We should save whatever species and habitats can be easily rescued (once-endangered creatures such as bald eagles and peregrine falcons now flourish), refrain from polluting waterways, limit consumption of fossil fuels and rely more on low-impact renewable-energy sources....We cannot thrive without crops or pollinators, or along coastlines as sea levels rise and as storms and flooding intensify."
But the anthropocentric view of the world that he presents is the opposite of moderation. It favours only humans. In many ways it's the other extreme of the Half-Earth proposal that suggests we set aside half the planet made free of humans. Having been told we don't need to value species beyond our current needs and interests assumes that we will capably and correctly identify those needs and goals, including for time frames beyond our own myopic lifespans. This uncertainty means that a human-centric view may be just as harmful to humans as approaches that ascribe value for biodiversity more value. And humans have proven willing and capable of taking much broader and more effective actions, that accommodate both humans and other organisms. (As FDR said and did: "We have fallen heirs to the most glorious heritage a people ever received, and each one must do his part if we wish to show that the nation is worthy of its good fortune.")

It's frustrating to see this kind of description of biodiversity as though the earth is simply a plus-minus ledger of species – a few lost here, a few gained there.

A conservation baseline is meant to capture an idealized Eden is of course unreasonable. But Pyron's view looks like Hell. ("If this means fewer dazzling species, fewer unspoiled forests, less untamed wilderness, so be it. They will return in time.")

Edit (Nov. 24): the TL:DR is that 
a) I thought the author cherrypicked the ecological literature and downplayed what we know about the loss of biodiversity and the complex/negative effects of human actions; 
b) if the argument is that we should think about biodiversity over timescales of millions of years, humans don't matter anyways; 
c) if we do care about humans, utility values of biodiversity are an acceptable focus of conservation. But it would be misguided to think that we have a perfect understanding of how ecosystems work or a perfect ability to forecast our impacts. For reasons of uncertainty, sampling effects and option value argue that we preserve as much diversity as we can;
d) Non-economic utility values (aesthetic, cultural values) are a good argument for conservation too. Most of us want to leave our children a beautiful planet that is full of life. 


Simon Leather said...

Excellent response to what I felt was a deeply flawed post by Pyron

Caroline Tucker said...

Thank you. I really tried not to write from a place of anger, but I have to admit I was pretty upset that the Washington Post published something so flawed, in terms of ecology and conservation science and science communication (I assume the author's intentions were more or less good).

Ray Cannon said...

Thank you for this interestingly and thoughtful response to what was an appalling piece in the Washington Post. I was reassured to see that most of the comments posted on the WP website took umbrage with, and challenged the writers depressing, anthropocentric view. I posted my on little comment, which I am pasting here as well.

'What a sad delusional piece. He makes so many category errors. Post-extinction recovery of biodiversity takes millions, if not 10's of millions of years; the human race will be long gone. So our lot is to sit out our time in a bioempoverished world? The biodiverse world we inherited is the most valuable thing on earth, perhaps even in the universe? Each species is precious and unique and what right do we have to select only those species we think are useful to ourselves?
And even if we impose our utilitarian choices, how the heck do we know what will be useful to ourselves in the future? The impact of invasive species is well documented but it is becoming trendy to pretend that everything works out in the long run, and who cares if the rare and unobserved go extinct. Council of doom.'

Louis Proyect said...

Ran across this trying to find out where Pyron was coming from. It is of some note that he was a child prodigy, starting college at the age of 12 and getting a PhD at the age of 22. It strikes me that he simply lacks the breadth of knowledge that would permit him to understand the history of civilization. His fatalism is extraordinary as if the disappearance of whales, gorillas, and polar bears can be balanced by the emergence of some new species of frogs in the Everglades. His idea of "diversity" lacks a fundamental dimension: quality. It is strictly quantitative and as such morally deficient.

RoseWrites (aka sousababy) said...

It's not "part of evolution" when a species is artificially infected with Wolbachia (a reproductive parasite). And sadly, endangered species have more legal protection (in Canada, currently) than human beings.

This type of hype is geared to absolving the billionaires who are invested in Wolbachia-infected Aedes male releases (which includes Bill & Melinda Gates, USAID, 3 other gov'ts, and 2 family foundations) of any wrongdoing.

Unknown said...

Excellent response. I was so disillusioned by Pyron's article. So shallow and no in-depth research.

Caroline Tucker said...

Thanks all for your comments. One positive outcome for me was that so many of the commenters on the piece recognized its flaws.

Stam Zogaris said...

Excellent response dear Caroline (thank you!!!) You should publish this somewhere else too. Your writing is quite dazzling...

Richard Harris Podolsky said...

I did not miss the irony that Pyron sits in a chair named for Robert F. Griggs a botanist who wrote one of the first books on the importance of studying rare plants......

bdalzell said...

I am a paleontologist. His time line is off. The really notable mass extinctions are at least 100 million years apart and they vary as to types of organisms impacted.

The really under appreciated BIG one was the Permian-Triassic die off which was 250+- million years ago with an estimated toll of 95% of earth life.
"96% of all marine species[6][7] and 70% of terrestrial vertebrate species becoming extinct.[8] It is the only known mass extinction of insects.[9][10] Some 57% of all families and 83% of all genera became extinct. Because so much biodiversity was lost, the recovery of life on Earth took significantly longer than after any other extinction event,[6] possibly up to 10 million years.
Wikipedia has some excellent summary articles on these events. I thought of writing an essay but I will just refer readers to some of the articles: