You've probably heard, and may have received, advice to "never let your guard down". Although this tends to make for somewhat unsatisfactory social interactions if taken literally, this is defensible advice. Except in social animals, where some degree of protection may be given to the very young, old, and ill, being weak tends to be deadly. We see this among plants, where individuals stressed by drought or other adverse conditions become fair targets for insect infestation and attack by fungal, viral, and bacterial diseases. The same type of thing is seen among animals, where on average it tends to be the young, the enfeebled old, and the sick who are picked off by predators.
In some cases, this may actually be good from the point of view of the
population, though obviously not from the viewpoint of the suffering individual.
Culling of the sick and old leaves more resources for the hale and hearty.
Nevertheless, if the lessons of nature were moral rather than amoral, this would seem
to be a good example of piling on.
Listen to the Audio (mp3 format) as recorded by KTEP, Public Radio for the Southwest.
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.