The Contrarians of Invasion Science and Ecological Restoration

 Western science has a tradition of the heroic contrarian who is proved right: Copernicus, Galileo and Darwin come to mind. In his Structure of Scientific Revolutions (1962), Thomas Kuhn explored how and why these radical shifts occur.

 Another more recent “tradition” is the contrarian-science book that is more about political advocacy and book sales than it is about exploring scientific discrepancies. In the past 20 years, contrarians published scores of books aimed at mainstream medicine (most recently against vaccines), and climate science. As Carl Sagan once said that yes, “they “ laughed at Columbus and the Wright Brothers, but “they also laughed at Bozo the Clown”.

In the case of climate science, contrarians are even pushing the idea that increased CO2 will be an unmitigated good thing.

Now contrarians are taking on the idea of “invasive species” and ecological restoration. Part 1 will cover general criticism and a couple of recent books. Part 2 will discuss in depth the most pernicious criticism: that love of native plants (and animals) is somehow xenophobic, and started with the eugenics movement and the Nazis.

Part 1 The Weak go Extinct, the Strong will Prosper. Does “Natural” or “Native” Mean any thing?

Everything is Natural

Reviewers are treating Chris D. Thomas’s Inheritors of the Earth (PublicAffairs, 2017) kindly, calling it “optimistic”. A 110 year old person buying green bananas is optimistic, Thomas is a Pollyanna of the first water.

In at least one interview, he said he almost didn’t write the book, knowing it could cost him professionally. However, he wrote a paper in 2013 (“The Anthropocene Could Raise Biological Diversity”. Nature, 502,7) that puts forth the same arguments. In fact, Richardson and Ricciardi cite this article in their “Misleading Arguments” paper.

Thomas’s book is a virtual tour of the “misleading arguments” paper:

Exotic species increase diversity, their negative effects are exaggerated, this is nothing new, and more species is a good thing, period. We are betting on “the losers” and should embrace “the winners”. So yes, invading rats have been responsible for ecological havoc, particularly on islands with ground dwelling birds, but as Thomas says:

“Despite their poor reputation, rodents are intelligent, resourceful animals; cute even, with their large eyes and ears, twitching noses and elegant whiskers.”

And plague. He forgot to add “plague”.

He goes on to say that

“The heirs to the world already surround us. However, when we move these really successful types to locations where they did not previously exist, there are casualties.”

So in a million years or so, we will have 20 new species of rats to make up for losing a few species of flightless birds.

He makes the case for throwing in the towel on controlling destructive exotic species:

“Like it or not, these biological gains will not go away and more changes will take place in the future. Regarding these changes as unnatural and undesirable is a myopic view of the world. ..We kill successful species to protect unsuccessful ones.”

His passing attack on “naturalness” was not isolated.

A criticism of invasive science and native plant advocacy Richardson and Ricciardi did not list is what could be termed tautological reductionism. John Brey, an anti-Darwinian Christian philosopher states:

“ For if the [scientific] materialist considers the state of the universe at the big bang ‘natural’…then it is difficult to imagine a place where the word ‘natural’ would not apply. Consequently, if everything is natural, then nothing is natural. The term ‘natural’ must differentiate one state for another-otherwise it is employed as a totally meaningless tautology-whereby the materialist speaks profoundly concerning the naturalness of nature.” Tautological Oxymorons , Brey, 2002

Brey believes that the entire idea of “natural selection” is tautological (no actual difference exists between natural and “artificial” selection) and tries to use the deconstructionist language tools of Jaques Derrida and the earlier work of Wittgenstein to discredit scientific materialism in general , and evolutionary science in particular. In his Tractatus Logico-Philosophicus (written in the trenches of WW1), Wittgenstein addresses sense, nonsense, tautology and language:

“The sense of the world must lie outside the world. In the world, everything is as it is and everything happens as it does happen.”

 Wittgenstein is difficult to understand, but this quote means that all statements about the world that are true are tautological (in the sense that Wittgenstein meant it), because “it is what it is” (a statement I had always associated with the Pointy Haired Boss in the comic Dilbert).

It is a bit of a surprise to see Thomas-a scientist-make exactly the same argument as Brey against the notion of the “natural”.

“..we know, objectively that the human species evolved naturally, so humans must be natural. We are a part of nature. Accepting this, the perspective that ‘humans are making nature less natural’ is the equivalent of saying that’ nature is making nature less natural. ..Why would we regard these new, human-altered ecosystems as any less natural that the ecological and evolutionary process that are still operating within them? …Nature just happens and the distribution of species change… 

Professor Thomas makes the case that the term “natural” is tautological and meaningless. So following this logic, why should we prefer a springtime old-growth Appalachian cove to an industrial brownfield covered in exotic weeds?

He says:

When we perceive nature to be blemished, we attempt to ‘restore’ it to some past state, just as we might try to repair a damaged masterpiece. To do so requires us to weed out those plants and animals we think are in the wrong place.

Thomas and Brey try to obliterate distinctions between what is relatively free of human influence and what is human dominated. Brey is making a case against the foundations of modern science. He states accurately that

“the meaning of a word is derived in every respect from its antithetical contrast with another word..”

But Thomas, presumably a scientific materialist, makes an unsupportable case (whether he meant to or not) that gradations of “natural” are meaningless (this is not reductio ad absurdum; as Brey pointed out: if all is natural, then logically, nothing can be natural, as there is not antithesis-the entire concept is a meaningless tautology), which from an environmental-ethical standpoint is repugnant and nihilistic.

Thomas is playing semantics. He is talking about natural as “what is”, while he surely knows that the word is also used to mean “that which is not intensely affected or intensely used by humans”. We certainly need a word that makes a distinction between a thriving prairie and a cityscape or 100 acres of corn, and I think “natural” works just fine.

Biologists have studied the positive effects of re-introducing wolves to the Yellowstone ecosystem. The system is now more “natural” and diverse related to un-doing human-driven local extinction of the wolves. Just as it is meaningful to study the affects of wolves or beavers on a given system, why is it NOT meaningful to study-and sometimes correct- the effects of the most dominant creature on the planet: humans.

Medical literature also supports the idea that walking in natural areas (vs an intensely urban environment) has positive effects on cognition and depression, among other benefits (for example this 2015 article: ). Despite Thomas’s preposterous mental gymnastics, humans are making the world less “natural”, and it is possible to measure how remaining natural areas benefit our mental and physical health.

Thomas also complains that we are wasting precious resources on protecting “loser” endangered species. However as noted by Matthew Holden in “Conservation from the Grave: Human Burials to Fund the Conservation of Threatened Species” (published in Conservation letters , the cost to save all endangered or threatened species in the world is not all that great even compared to the funeral industry:

“Considering 2.7 million Americans die each year (Xu et al. 2016), potential funeral revenue is roughly $19 billion/year. This is far more than the estimated $3.4-$4.8 billion/year required to protect and manage the habitat of every IUCN threatened species in the world (McCarthy et al. 2012). While a large portion of funeral costs are for ceremonial expenses unrelated to the acquisition and maintenance of the grave site (NFDA General Price List Survey 2015), natural burials eliminate body preservation and use cheaper materials (Harker 2012; Kelly 2012). Conservation burials divert this saved money toward habitat protection and restoration. The average U.S. casket and embalming costs $2,395 and $695, respectively (NFDA General Price List Survey 2015). Therefore, if all Americans who embalmed their remains (45%; NFDA Cremation and Burial Report 2015) purchased a conservation burial instead, U.S. burials could produce $3.8 billion in conservation revenue. While not every threatened species can benefit directly from conservation burials, the hypothetical revenue demonstrates substantial potential for increased biodiversity.”

Considering that we also spend 28 billion dollars on pet food annually in this country and that the Gross world product is approaching 80 trillion dollars, maybe it won’t break the bank to spend less than 5 billion annually to save all endangered species (that is 1/16,000ths of the GWP).

Thomas says-in defending the rapid changes wrought by exotics and humanized landscapes:

“It is as if [restoration ecologists and invasion scientists think] there is an ‘ought to be’ state of the world”

I am an ontological realist: I think that animals and ecosystems exist independently of our observing them (believe it or not some philosophers differ), and take an ethical/moral position that these plants and animals have a right to exist independent of their meaning for me and other humans. Given that we are entering an era-the Anthropocene-where humans dominate or at least influence habitats planet wide, Aldo Leopold’s words make a lot of sense:

 “The last word in ignorance is the man who says of an animal or plant, “What good is it?” If the land mechanism as a whole is good, then every part is good, whether we understand it or not. If the biota, in the course of aeons, has built something we like but do not understand, then who but a fool would discard seemingly useless parts? To keep every cog and wheel is the first precaution of intelligent tinkering.”


We shall never achieve harmony with the land, anymore than we shall achieve absolute justice or liberty for people. In these higher aspirations the important thing is not to achieve but to strive.”

Aldo Leopold, Round River: From the Journals of Aldo Leopold

Leopold is being a bit mechanistic and teleological in the first quote, and I agree with Stephen S. Gould that ecological communities do not function like well oil machines with every part essential. But I also believe that “novel ecosystems” advocates like Thomas are extraordinarily arrogant in presuming that we are entering a grand new era of biological diversity related to humans dominating the planet. He does not seem to be considering that humans are intensely using more and more of the world’s resources and “ecological spaces”. Where will these new species evolve, particularly the larger ones?

Thomas sets up a straw man, characterizing those of us committed to conserving native species as dewy eyed, ignorant romantics who want to freeze existing ecosystems in amber. This is not true. But in protecting rare species we often have to protect broader habitats that benefit other plants and animals in ways we do not yet understand.

I think we “ought to” make efforts to kill off as few endangered species as we possibly can. We should commit the resources. We might not achieve but we should strive. I do not feel the loss of the last Sumatran rhino (and the end of the line for all wooly rhinos) will be ok as long as we have five new species derived from feral cats millennia hence. Not that I hate domesticated cats. I don’t. Really. OK, I ‘m not a huge fan of feral cats and I am a dog person….Thomas’s book is worth reading, and I actually agree with him on some things-he notes that (like Florida yew) perhaps a quarter of all species will become climate refugees and would need assisted migration, and seems to be a fan of de-extinction. He remains in his heart a conservationist. While clinging to his denial of the existence of the unnatural, he says:

“Humans are natural within the Earth system, and so it follows that anything we do or don’t do, is a perfectly natural consequence of the evolution of a bipedal ape. We can intervene in ways that old-thinking would define as “unnatural”. We can be proactive rather than bowed over with regret that things are no longer as they were.”

He is saying that actively saving species can also be a completely natural thing for humans to do, and he seems to advocate saving areas large enough to save big animals from extinction.

Native Plants do Not Exist

The award winning British science journalist Fred Pearce’s 2015 The New Wild-Why Invasive Species will be Nature’s Salvation (Beacon Press) makes the case that 1) “native” plants and other organisms do not exist and 2) what we call “invasives” actually increase biological diversity and (as the book cover says) “Will be Nature’s Salvation”. He also makes links between Nazis, eugenicists and native plant advocates, and blames restoration ecologists for dooming the Florida panther. The rest of the book is a re-hash of Thomas’s and other contrarians’ themes. Despite rave reviews from the likes of Stewart Brand, James Lovelock and Kirkus Reviews, Pearce is either a very poor researcher, or he has created a one-sided, cartoonish portrait of main-stream restoration ecology intentionally to sell more books (or both). Full disclosure: I hated this %$#$% book. Don’t buy it unless you are an intellectual masochist like me.

His most ridiculous statement is similar to Thomas’s denial that “natural” is even exists:

“A broad time horizon shows there is no such thing as a native species.” P. 50

Yes and every life form in the universe came from the same 10 to the minus 35th meter space that existed at 0-10 minus 43rd seconds of the Big Bang event, so all life in the universe (now 13.7 billion years afterwards) could be considered native to anyplace in the universe, I guess.

Pearce apparently wants to limit his discussion to earth, so in his opinion, any location other than where the first self-replicating organism developed in the primordial ooze is a place life invaded. If all species come from species that migrated from elsewhere, then in Pearce’s opinion, the idea of native species is meaningless.

Degrees of naturalness exist, and are ecologically meaningful; so it is with the concept of native species.

Consider the case of salamanders in the Southern Appalachians. Among the lungless salamanders (plethodontidea), the subfamily pelerpinae originated there more than 70 million years ago. They are still there. Keep in mind that the first primate fossils date to 55 million years ago. Pearce would make the case that calling them “native” is a meaningless distinction, even when comparing salamanders and kudzu.

He loves examples like species-depauperate, newly formed islands and his own United Kingdom (other than land south of the Bristol Channel entirely covered by glacial ice sheets until 18000 years ago) as why invasive species are such a treat wherever they go. As I pointed out in the last post, no one is saying that ANY new species ANYWHERE is a bad thing, only that the scale and speed of these invasions is unprecedented and in many places (like privet in our alluvial communities at Ramsey Creek and at least 3 million other acres in the south) threatens diverse native communities.

He says when people vilify kudzu “ something cultural [is] at work here”:

Kudzu’s incontinent growth, extending roots underground to form new vines on the end, seems to fit an American image of the Deep South as somehow depraved and unruly.”

What? Ok, I live in the “Deep South”, and hate kudzu. I don’t think cultural depictions like the movies “Deliverance” or “Sling Blade” are what made kudzu almost universally hated. I agree that is not actually eating the South, and unlike privet and Asian honeysuckle, it is surprisingly easy to control without chemicals-we are close to eradicating it at Ramsey Creek (a good article on the kudzu issue is here: ).

He says that the wildlife-teeming plains of Africa are almost an entirely new phenomenon created by rinderpest (a disease that eliminated domestic cattle), and that Amazonia is entirely a by-product of intense human activity.

Of the latter, humans no doubt helped shape Amazonia, and for years this influence-particularly in eastern sections-was grossly underappreciated . However, 3 years BEFORE he published the book, an article appeared in the journal Science ( ) that debunked the idea that all of Amazonia is a human creation. In fact, the vast western regions were probably always sparsely populated . I guess he was too busy writing to keep up with the latest literature-especially that which countered his narrative.

Two items make Pearce’s attacks on invasion science, restoration ecology and native plant protection particularly obnoxious: his ill-informed account of the plight of Florida panthers, and his explicit linkage of native-plant advocates to eugenics and the Nazis.

The Florida panther has been in trouble for decades. By the 1970’s the animals were down to 12-20 animals, and while the population rebounded (perhaps 200 exist now), by 1993 they were suffering from severe inbreeding issues: genetic defects that caused atrial septal defects, low sperm quality, immune deficiencies and other problems. A 1990s task force recommended expanding protection and a long term goal of establishing 2-3 meta-populations of 240 animals each. One issue is that the home range of a male panther is normally 200 square miles and the female’s is 75. The task force hoped to see 2-5 animals per 100 square mile (around 64,000 acres). They projected the need of 4800-12000 square miles for EACH meta-population. They also introduced several females from a closely related subspecies from Texas to address the genetic problems.

photo: Denguy, Defenders of Wildlife

In Pearce’s retelling, restoration ecology advocates “sacrificed” the Florida panther by insisting on eliminating exotics and restoring natural cover to 6300 acres of former farmland that was surrounded by the Everglades: the so called “Hole in the Doughnut” (HITD) tract. In 1954, farmers began “rock plowing” on the 20,000 acre Long Pine Key,-an area of slightly higher ground -to create around 9000 acres of arable farmland. Farming ceased in 1975, but the area was soon overrun by Brazilian Pepper, an intensely invasive species that is poor habitat for hogs and deer, the main food source for panthers. In 1997, the Park Service began restoration of just under 10 square miles (6300 acres) of the 9000 acres that had once been farmed. About 4100 acres of old farmland had been restored by 2010 ( . More than 50% of the rock-lands had remained natural and was unaffected by the farming efforts.

Pearce says of that 6300 acres:

Fleeing traffic and tourism in the more picturesque parts of the park, the cat…..found the overgrown farms in the Hole-in-the-Donut an ideal refuge. Its numbers began to rise.”

After restoration began, he says:

What about the panthers? Concerned about the possibility that the ecological restoration might result in their extinction, park authorities augmented their stock with some females from Texas.”

After surmising that the resulting cats were “hybrids” he concluded

An subspecies of iconic cat has been sacrificed in order to fill the Hole-in-the-Donut.”

The only problems with this narrative are the timing of the panthers’ decline and interventions to save the panther, and the scale of the project related to known panther habitat requirements.

The plight of the panther goes back to the 1960s and 1970s when the population reached a nadir and entered an unsustainable “genetic bottle neck”. It was listed as endangered in 1967-over 50 years ago, some thirty years before the HITD restoration efforts cranked up.

Farming in the HITD stopped in 1975, but panther rebound is related to setting up large panther reserves after 1981, measures to limit traffic kills,  and improvements in reproductive fitness after introducing 8 non-pregnant females from Texas (see the Panther Recovery plan from the Fish and Wildlife Service here : ).

The decision to introduce Texas panther genes predates the restoration project’s implementation and is unrelated. And panther population growth increased after the restoration project started. This from the Fish and Wildlife Service:

“Between 1991 and 1994, biologists convened three workshops to discuss the genetic health of the Florida panther population. Experts in the fields of genetics, conservation biology, captive breeding, and panther biology participated. Scientists concluded that some means of restoring a level of gene flow to the population was critical to improving the genetic health of the panther and its long-term prospect for recovery.

 A genetic restoration plan was implemented in 1995 with the release of eight female pumas from Texas into Florida panther habitat in southern Florida. Texas pumas (P. c. stanleyana) were the closest extant puma population to Florida and the intent of this plan was to mimic the gene flow that historically occurred between these subspecies. Five of the eight Texas pumas produced a total of at least 20 kittens. None of the original eight Texas pumas remain in the wild population today; five died from various causes and the remaining three were removed from the wild and placed in captivity after they produced a sufficient number of offspring. Subsequent analyses have already documented the beneficial impacts of genetic restoration on the genetic health of the population as well as the coinciding increase in panther abundance since 1995.”

And if one female panther requires 48,000 acres, and a male more than 100,000 acres, it is hard to imagine that 120 animals were dependent on 6000 acres of deer-poor Brazilian pepper, even given the disproportionate importance of uplands to panthers. The task force hoped to see 2-5 animals per 100 square miles. 6000 acres is about 10 square miles.

Pearce threw out the panther/restoration ecology nonsense in 2 pages that are pretty convincing on a quick read. The book is chocked full of assertions that on closer inspection fall apart. The most noxious is his characterizing native plant advocates as quasi-Nazi, a smear he brings up repeatedly. Rats are not eliminated from the island of South Georgia, they are victims of a “pogrom”. In two different chapters, he brings up the fondness Nazis and eugenics advocates expressed for native plants.

“Eugenics generated calls for societies to be cleansed of inferior, alien, and unfit humans. Clementsian ecology led to a similar view of alien species.

 The two theories also had common adherents. Many conservationists in the first half of the twentieth century were prominent proponents of eugenics.” P. 141

 A lot to unpack here, but it is a fascinating history that anti-environmentalists and contrarians like Pearce have been harping on about for years. This will be the main subject of part 3.