The Speculist

In a recent Commentary at Nature's website, Cornell University Doctoral student Josh Donlan (academic homepage) previews a modest proposal ^[1]

The proposal:

...to actively promote the restoration of large wild vertebrates into North America in preference to the 'pests and weeds' (rats and dandelions) that will otherwise come to dominate the landscape. [It] would be achieved through a series of carefully managed ecosystem manipulations using closely related species as proxies for extinct large vertebrates, and would change the underlying premise of conservation biology from managing extinction to actively restoring natural processes.

involves importing large, contemporary, savannah-dwelling, vertebrates of all trophic persuasions (herbivores, carnivores, and omnivores) from Africa into the Great Plains of the United States (and, presumably, Canada) to take on the ecological roles vacated by native species at the end of the Pleistocene Epoch (c. 1.7MYA - c. 10,000 YA) presumably due to anthropogenic ('human-caused') extinction as a result of the contemporaneous in-migration of pre-historic humans at the end of the last Ice Age.

Mr. Donlan and his coauthors justify this change “from manag[ement] … to active restor[ation]””… on ecological, evolutionary, economic, aesthetic and ethical grounds” and offer the following five premises to support their conclusion:

_        “First, Earth is nowhere pristine; our economics, politics, demographics and technology pervade every ecosystem. Such human influences are unprecedented and show alarming signs of worsening.

_        Second, environmentalists are easily caricatured as purveyors of doom and gloom, to the detriment of conservation.

_        Third, although human land-use patterns are dynamic and uncertain, in some areas, such as parts of the Great Plains in the United States, human populations are declining — which may offer future conservation opportunities.

_        Fourth, humans were probably at least partly responsible for the Late Pleistocene extinctions in North America, and our subsequent activities have curtailed the evolutionary potential of most remaining large vertebrates. We therefore bear an ethical responsibility to redress these problems.”

While we at the Speculist are usually quite in favor of ambitious plans to take dangerously arbitrary ‘natural’ processes under more active control and to foresee and mitigate future or discover and remediate past changes to the environment (anthropogenic or otherwise) with the clear goal of benefiting human life and intelligence and preserving and appreciating the diversity and capability of all life forms wherever we find them, the reasons advanced by Mr. Donlan, and company and the actions proposed on the basis of those reasons, places them in contention for our late “Buzzkill of the Week” award.

Addressing the Cornell team’s premises in turn:

“Earth is nowhere pristine; our economics, politics, demographics and technology pervade every ecosystem. Such human influences are unprecedented and show alarming signs of worsening.”

Like many other scientists before them, Donlan and company operate under a dogmatic assumption that unduly complicates their analysis. In this case the assumption that the existence of humanity, its activities, and its intelligence, is, in some way, super-natural. Left outside of what is properly called nature, any action of humanity that in any way impacts anything within the pale is immediately un-natural, disruptive, bad, and, to use Donlan’s term “worsening”. Given the team’s proposed interventionist solution to the perceived problem, this seems, at best, self-contradictory.

“Second, environmentalists are easily caricatured as purveyors of doom and gloom, to the detriment of conservation.”

While the social perception of scientists who study and teach about the interrelationships among lifeforms and between those lifeforms and their physical surroundings may be of some immediate concern to those scientists, this reflected version of the ad hominem argument has more to do with why the investigators are pursuing this course than with why others should join them.

“Third, although human land-use patterns are dynamic and uncertain, in some areas, such as parts of the Great Plains in the United States, human populations are declining — which may offer future conservation opportunities.”

This observation, frequently advanced by those residing outside the area in question in support of actions that disproportionately benefit themselves while not necessarily conferring any benefit on the residents, has been advanced in support of several other propositions in the past from the original Colorado River Compact to the Buffalo Commons. It is a form of the same elitist / colonialist attitude that lead to trouble between Great Britain and her Colonies.

“Fourth, humans were probably at least partly responsible for the Late Pleistocene extinctions in North America, and our subsequent activities have curtailed the evolutionary potential of most remaining large vertebrates. We therefore bear an ethical responsibility to redress these problems.”

The triple conditional Donlan sets up in the opening sentence casts considerable doubt on the remainder of the assertion. I would also like to see some estimates of the average numbers of tons of biomass per square kilometer represented by vertebrates of, say, 100kg and greater in the Great Plains in modern and Pleistocene times. Given that other ecologists are decrying the energy subsidy of feedlot cattle production through petrochemicals used in transportation and feed production, I wouldn’t be surprised to find that the current figures are as large or larger.

Other elements of Donlan’s proposal seem to indicate insufficient consideration of consequences. For example, the investigators propose the substitution of African-evolved proxies for extinct North American megafauna in their neo-Pleistocene conservation parks. I am hard pressed to remember a case where human introduction of a alien animal species to an ecosystem has not either driven native species to near extinction or resulted in plagues of the introduced species overrunning and depredating the ecosystem they’ve been introduced to. Wild dogs and rabbits in Australia, snakes in the Hawaiian Islands, wild pigs in Texas, and other examples come readily to mind. Further, the species proposed for introduction all pose some danger to human life and property. Living in an area where large animals already pose dangers to life and property (from bears and puma, or mountain lions ^{[2] , [3]} , to bison ^[4] and deer) I, personally, do not necessarily think that adding two kinds of pachyderms, two great cats, and camels to the list represents a practical improvement. Finally, at least for now, the researchers make no mention of the possibility that the species they propose to introduce might serve as reservoirs or vectors for diseases that might be transmitted to humans, their pets, or their livestock. The potential for adding newcomers to locals such as Bubonic Plague in certain prairie dog colonies, and Hanta virus, a hemorrhagic fever that has been compared to Ebola, in deer mice, also seems to speak against the proposal.

I look forward to the forthcoming discussion as first this article, then the full Nature article make their way through the blogosphere. This is among the first proposals to tackle the issues surrounding the biological aspects of terraforming any planet, much less remediation of the home planet, and will lead to discussion of both the moral and the technical implications of this sort of proposal.

[4] “Kramer orders inquiry of killing of 5 buffaloes”