The 6th Mass Extinction: A Serious Crisis

Although alarming, deforestation, global warming and a growing endangered species list are only symptoms of a far more complex dilemma in which the lives of 40-95% of Earth’s known species are at stake (Whitty). This crisis is referred to as the Anthropocene, or the 6th Mass Extinction (Whitty). As Deborah Bird Rose, a biology professor at Macquarie University points out, “Prior to the emergence of Homo sapiens, Earth’s extinction rate was about 0.0001% per year” (Rose 81). Current extinction rates are at about 0.1% per year (Rose 81). This means that 13,000 species die out every year and 35 die out every day (Rose 82). Researchers of this field have little doubt that the extinction rates are very high. The controversy lies in whether or not this era qualifies as a mass extinction. Studies conducted by Stuart Pimm, a conservation biologist at Duke University, and Adam G. Jones, a biology professor at Texas A&M University evidence a modern extinction theory. However, Sean Nee, a researcher at Ashworth Laboratories at the University of Edinburgh, argues that Earth is undergoing a natural cycle of nature, not a mass extinction. Nonetheless, soaring extinction rates, habitat destruction and climate changes lend credence to Pimm and Jones’ assertion that Earth is indeed in the midst of a 6th mass extinction.

Nee, an opponent of the modern extinction theory, contends that the seemingly enormous differences between the modern crisis and the past five extinctions indicate that this is merely a natural phenomenon. The previous five extinctions had a recurring symptom of pollen being replaced by fungus spores while the Anthropocene does not (Nee 3). In addition, he argues that this extinction crisis would not be noticed if not for the constant reminders from ecologists (Nee 4). Even if there are certain species taking dramatic plummets in numbers, attention should not be drawn from the fact that other species have booming populations (Nee 3). For example, “many species of island birds are threatened while British seabirds are proliferating rapidly” (Nee 4). Additionally, most amphibians are on global decline dying, but Cane Toads are a major pest (Nee 4). Although Nee’s arguments may sound reasonable, a closer analysis reveals several irrationalities within his theories.

Utilizing evidence from an evolution model in a two-species community, Jones gives corroborating evidence of a 6th mass extinction and refutes Nee’s claims. Jones asserts, “Rapid human-induced changes in the environment at local, regional and global scales appear to be contributing to population declines and extinctions, resulting in an unprecedented biodiversity crisis.” (Jones 1). He found that habitat conversion exceeds habitat protection at a 8:1 ratio in temperate grasslands and Mediterranean biomes and a 10:1 ratio in the over 140 ecoregions (Jones 8). The land that is converted is often used for corn production because corn is an integral factor of biofuels (Jones 8). To meet the goals of biofuels for 2017, about .5% of Earth will be required; this in turn will kill twice as many species as current designated biofuel lands are already killing (Jones 7). In short, mankind’s rapacious consumption of biofuels alone compounded with an exponentially expanding population is of enormous detrimental effect to biodiversity. In substantiating the validity of a man-made mass extinction, Jones succeeds in countering conflicting ideas. Since the Anthropocene is revolutionary in that it is caused entirely by humans, it can not be expected to be identical to the previous five extinctions, or the Big 5. Today, there are bulldozers, nuclear testing, and pollution galore. This was obviously not the case 300 million years ago. Stuart Pimm, another significant advocate of the modern extinction theory, disproves the rest of Nee’s beliefs using results from his research on species diversity

In order to accurately determine current extinction rates, Pimm conducted studies on mammals, reptiles, frogs, toads and freshwater clams. Results of his studies indicate that the current extinction rate is two levels above the norm (Pimm et al 164). One major reason is the large-scale destruction of earth’s biodiversity hotspots –small areas of land that shelter large numbers of species (Pimm et al 164). Pimm declares, “These hotspots contain representatives of 44% of all plant species and 35% of all birds, reptiles and amphibians” (Pimm et al 165). This constitutes a possible loss of 50-66% of all of Earth’s known species! When cross-referenced with statistics from the Big 5, it is clear that the Anthropocene is at least on par with the mass extinctions. Furthermore, the remaining arguments against the modern extinction theory can be swept away by qualifying Pimm’s research with the basic meaning of a mass extinction . Georgina M. Mace, a director of science at the Zoological Society of London contends, “Extinctions are based on species diversity, not species abundance” (Mace 1435). The fact that one species is thriving can not compensate for the dying out of a plethora of others (Mace). It is naïve to assume that what one can’t see does not exist. This argument to ignorance is easily dispelled by the logical analysis of Pimm’s statistics. The Anthropocene will be on par with Big 5 in a matter of 50-100 years (Pimm et al 164). The effects of the modern extinction are quite palpable and can be easily seen on Pimm’s results.

The Anthropocene is indeed the newest member in the ranks of the Big 5. While having been caused by mankind, it is also possible for man to amend the nature he ravaged. According to author and environmentalist Julia Whitty, “It is actually possible for humans to protect to some extant, 95% of all flora and fauna on this planet!” (Whitty). First, however, the Anthropocene must be recognized as a bona fide, tangible jeopardy whose presence is already felt in the razed forests of Brazil, the melting ice of the poles, and the lone cry of Mother Nature’s last Ivory-Billed Woodpecker.