The following excerpt from The Moon in the Nautilus Shell: Discordant Harmonies Reconsidered, by Daniel B. Botkin (Oxford University Press, 2012. Copyright © 2012) appeared in Scientific American magazine on December 7, 2012.
“Reality must take precedence over public relations, for nature cannot be fooled.”
—Physicist Richard Feynman in the final report on the Challenger disaster
Life has had to deal with environmental change, especially climate change, since the beginning of its existence on Earth. Species adjust or go extinct, and both have happened. For life-forms with our kinds of cells—eukaryotic, the kind with distinct organelles—the average existence of a species is about 1 million years, and, on average, one species goes extinct a year, at least of the species we have named and know, including those we know only from fossil records.
Organisms adjust to environmental change in three ways, from fastest to slowest: behaviorally, physiologically, and genetically. Ecologist Larry Slobodkin used to demonstrate the first two playfully during a lecture by picking up a piece of chalk and tossing it to one of the students. The student would duck or catch the chalk, which Larry pointed out was the behavioral response, first and fastest, and then within 20 seconds would blush, the physiological adjustment, second fastest. These, he would explain, were not only relatively fast but used little energy in a population. If these failed to make a successful adjustment, a population’s genetic makeup could change, with genes transmitted to the next generation that led to characteristics better adjusted to the changed environment, obviously a much slower adjustment.