A survey of scientific responses to extinction at the present moment is fairly unambiguous, however. Paleontologist James Kirchner calculated in 2002 that extinction rates could more or less be statistically inferred from the fossil record, and uses this to quantify what he terms "evolutionary speed limits," which is to say the rate at which the Darwinian process of natural selection (which depends upon the effective extinction of species insofar as they will diversify and evolve into other species) to note that, in the current moment, the extinction rate proceeds so rapidly that "diversification rates are unlikely to accelerate enough to keep pace with it. Thus, widespread depletion of biodiversity would probably be permanent on multimillion-year timescales." (67). This emphasis on biodiversity, which is of course readily quantifiable by science, is ambiguous however, insofar as there is no ready way to predict the consequences of such a rapid decline in biodiversity. This is emphasized by Bradley et al. In a 2012 article for Nature, where the authors note that "Functional traits of organisms have large impacts on the magnitude of ecosystem functions, which give rise to a wide range of plausible impacts of extinction on ecosystem function." (61). In other words, all of the different ecological roles that might have been played by the vast number of passenger pigeons in the North American ecosystem are impossible to quantify in full -- to some extent, even a hundred years after their extinction, this remains a scientific experiment in progress whose upshot cannot yet be confidently summarized. More to the point, as Naheem et al. indicate in a 2012 article for Science, it is entirely possible that the way in which the human imagination approaches these issues -- by offering cute names to the last animals of their species, or focusing on the preservation of charismatic species rather than the more abstract conception of preserving biodiversity within whole ecosystems -- may actually draw attention from the more scientifically significant activity: regarding the present scientific emphasis on biodiversity, Naheem et al. write

This focus is sometimes understandably seen as contrary to widespread and urgent conservation efforts to save species and ecosystems from extinction for non-utilitarian, cultural reasons. Indeed, species targeted for conservation, reserves, and protected areas represent a tiny fraction of the biosphere and are therefore not likely to strongly influence biogeochemically derived ecosystem services such as carbon sequestration and food production. Yet the cultural values of biological diversity can themselves be construed as ecosystem services, and their preservation is fully coherent with non-utilitarian conservation efforts and arguably no less important. Nothing in biodiversity and ecosystem functioning research should dissuade conservation from its efforts to bring our age of extinction to a halt. (1406)

This could be taken as a scientific way of noting the relative unimportance of, say, the Galapagos in the vast scheme of things. When Lonesome George becomes the public face of biodiversity depletion in the past five years, this leads to the movements to approach this small archipelago which is, to employ the words of Butchart et al., a "tiny fraction of the biosphere." The attempt to maintain and mate Galapagos tortoises and preserve them from extinction is thus a distraction from the more urgent trend of stopping the overall depletion of biodiversity, for the simple fact that the results of the larger trend are far more unpredictable. This is emphasized by Barnosky et al. In their 2012 article "Approaching a State Shift in the Earth's Biosphere," which notes that there is a fundamental unpredictability about biological processes until they reach an obvious tipping point:

It is now well documented that biological systems on many scales can shift rapidly from an existing state to a radically different state. Biological 'states' are neither steady nor in equilibrium; rather, they are characterized by a defined range of deviations from a mean condition over a prescribed period of time. The shift from one state to another can be caused by either a 'threshold' or 'sledgehammer' effect. State shifts resulting from threshold effects can be difficult to anticipate, because the critical threshold is reached as incremental changes accumulate and the threshold value generally is not known in advance. (52)

In other words, if we are indeed living through the Anthropocene Mass Extinction Event -- as plenty of scientists are willing to argue that we are -- then to some extent the full consequences of the event will only be quantifiable at the precise moment that it is too late to do anything useful to forestall it. This is consistent with the point made by Butchart et al. In their 2010 survey for Science, in which they consider what has actually been done to halt the loss of biodiversity, and they conclude that the only possible solutions would be extremely large-scale policy approaches:

Our results show that, despite...

(1168)
However this would require an alteration of the cultural landscape potentially as vast as the alteration humans are currently permitting to occur on the planet's ecosystems. The real difficulty is the gap between what culture is capable of imagining -- Lonesome George and Martha -- and what science is suggesting might potentially be required to halt the troubling present trends.

We return then to the question of the imagination, and here I would like to note an interesting cultural trend. In the beginning of the twenty-first century, the face of species extinction is Lonesome George, the Galapagos tortoise (representative of a small and geographically-constrained species). In the beginning of the twentieth century, the face of species extinction was Martha, the passenger pigeon (representative of a once-vast population that was exterminated with bewildering celerity). What was the status of extinction a hundred years before that, in the early nineteenth century? The culture of the early nineteenth century is, after all, what produced Darwin, and it is fascinating to note that the scientific state of that moment was only emerging from the belief that extinction was not possible. Darwin's deep influence by the geology of the time hinged upon the early nineteenth century scientific debate between Catastrophism -- the notion that the observable features of the earth (like mountain ranges) had been produced by a catastrophic event in the past (such as Noah's flood) -- and Uniformitarianism, the more recent theory advanced by Charles Lyell which held that "all elevations and subsidences of the land were due to the accumulated effects of observable causes such as earthquakes and erosion" (Bowler 61). Darwin's own conversion to Lyell's view -- which happened on the same expedition where he visited the Galapagos, and was influenced by his observation of an earthquake at Concepcion -- was crucial in his understanding that, just as the earth's features must have taken place through these slow gradual processes over millions of years, so did the emergence of species take place in similar fashion. But the parenthetical invocation of Noah's flood is meant to prove a point: science in the early nineteenth century was only gradually moving out of inherited paradigms from a theological worldview, and species were no exception. The Biblical story of Noah seems to indicate a God that occasionally destroys vast populations, but that also does not permit any of the species that He created to go extinct. In the early nineteenth century, the first sustained scientific considerations of the fossil record represented the route whereby these theological ideas would be questioned: after all, fossils had previously been thought to be evidence of animals exterminated by the Biblical flood.

Out of this cultural ferment in the early nineteenth century, then, emerges a new genre of literature, the "last of the race" narrative. This genre has been examined (in a workmanlike and incomplete fashion) by Fiona J. Stafford, who traces the slow emergence of this type of story from earlier fictions. But essentially, what becomes a fascination for culture in the early nineteenth century is the story of last representatives of their kind, the human equivalents of Lonesome George and Martha. We may see it operating in a kind of early sci-fi mode in The Last Man, an 1826 novel by Mary Shelley, the author of Frankenstein:

Patience, oh reader! whoever thou art, wherever thou dwellest, whether of race spiritual, or, sprung from some surviving pair, thy nature will be human, thy habitation the earth; thou wilt here read of the acts of the extinct race, and wilt ask wonderingly, if they, who suffered what thou findest recorded, were of frail flesh and soft organization like thyself. Most true, they were -- weep therefore; for surely, solitary being, thou wilt be of gentle disposition; shed compassionate tears; but…