Almost forgot to mention a piece of pseudoscience I watched on The Learning Channel last night that had me ranting and raving about that channel. An otherwise informative documentary about piranha decided it wasn’t enough to dispel some of the myths about the fish, but also insisted on waxing poetically about why such myths were so resonant with human beings. In the process it managed to delve into pseudoscience.
It turns out that piranha aren’t quite as ferocious as early explorers such as Theodore Roosevelt claimed. They will attack pretty much any wounded creature to be sure, but the locals in and around the Amazon have adapted and so long as you don’t jump in the water with open wounds or when animals are being slaughtered in waterways, piranha attacks on human beings are extremely rare.
Anyway, the TLC program insisted that the reason human beings fear piranhas is that they don’t understand that the piranha’s function in the ecosystem is to clean up waste biological products (and the fish are extremely efficient at stripping corpses), but went further and claimed that scavenger species such as piranha or vultures don’t “live for themselves” but instead live simply to serve the ecosystem.
Give me a break. Piranha and vultures don’t serve some altruistic pseudo-end, but rather have adapted to take advantage of the fact that a good living can be had in quickly finding and consuming dead and dying animals. The show was also filled with all these pseudoscientific mentions of a “natural balance” which is a common sentiment but fallacious since there is never any such thing as balance — the environment is constantly in flux (one need only pick a specific region and present day ecosystem to that of the region’s ecosystem one million years ago to see the fallacy in the concept of “natural balance”).
Finally, the reason why people generally fear piranha isn’t much of a mystery. Even after seeing some of the early claims about piranha debunked, I’m still not so sure I’d want to be swimming in a river filled with fish that can strip a 140 pound animal down to bones in just a few minutes. That such a small fish can do so much violence so quickly is probably why people who don’t live with the fish on a daily basis fear them.