Durk Pearson & Sandy Shaw’s®
Life Extension NewsTM
Volume 16 No.
5 • May 2013
PREDATOR VS. PREY
by Sandy Shaw & Durk Pearson
(originally appeared in Liberty)
A recent paper in Science on what caused the extinction of large North American canids (wolf-like carnivores) is startlingly parallel to what is happening to the government of the United States and its constituent states and leads us to a hypothesis concerning the death of democracies.
The paper reports that during the past 50 million years, successive branches of large carnivorous mammals have diversified and then gone into extinction. The authors argue that “energetic constraints and pervasive selection for larger size (Cope’s rule) in carnivores lead to dietary specialization (hypercarnivory) and increased vulnerability to extinction.” They explain that Cope’s rule—the evolutionary trend toward larger size—is common in mammals because larger size makes it easier to evade predators and to capture prey. Moreover, larger size improves thermal efficiency, thus increasing the potential range of habitats into colder areas. As the size of carnivores increases beyond about 45 pounds, the amount of nutrition obtained from small prey becomes inadequate to cover the energy used in capturing them. Thus, the larger carnivores became what the authors call “hypercarnivores,” which hunt only large prey (as large as or larger than themselves). A plot of the index of hypercarnivory (PCI score) against estimated species duration shows that none of the hypercarnivorous species persisted for more than 6 million years, as compared to other, more omnivorous species that lasted as long as 11 million years. Hence, the authors propose, the hypercarnivores are more vulnerable to extinction. The researchers also note that hypercarnivores reverting to a more generalized diet and morphology was rare.
Reliance upon a smaller number of large prey increases the statistical variation in the nutritional intake. Moreover, the larger the carnivore, the lower their population density. Both of these are factors that increase the risk of extinction. It is interesting that the government of the United States and of its constituent states are moving rapidly in the direction of targeting large prey, with an increasing statistical variance in the yearly revenue from these relatively small number of prey. The federal government relies heavily on a steeply progressive income tax (with the well known result that the bottom 50% of income earners pay only 4% of income taxes). Relying upon the fat targets at the highest level of earnings has resulted in greater statistical variation in revenues, as well as increasing demand for government services from those paying little or nothing for them. Worse yet, today’s government is already preying upon the fat targets of the future by rapidly increasing government debt, something canids never had the option to do.
We suggest, therefore, that hypercarnivory may be one reason that democracies don’t last much longer than about 200 years. If we start counting from the passage of the 16th Amendment on Feb. 3, 1913 (which provided the means to target most of the large prey via unlimited progressive income taxation) rather than from 1787, the United States could theoretically last another century or so, though for a number of reasons (the immensely rapid expansion of government debt, for instance) we think it unlikely.
- Valkenburgh et al. Cope’s rule, hypercarnivory, and extinction in North American canids. Science. 306:101-4 (2004).