Chapter 12, Alone in a Crowded Universe Summary and Analysis

Exobiology is a theoretical pursuit that ponders the likely nature and possible existence of extra-terrestrial life and intelligence. So-called exobiologists have proposed the Green Bank formula, a mathematical process that putatively determines the number of intelligent species in the universe. The formula includes numerous factors, all of which are estimated. Not surprisingly, the Green Bank formula can predict that humans are the only intelligence in the universe or that there are billions of intelligent species in the universe depending upon the estimates used in the various factors; most Green Bank estimates indicate that extra-terrestrial life and intelligence should be plentiful.

The author offers a rather lengthy investigation of the woodpecker group of species, noting that all woodpecker traits are found plentifully in other bird species and yet all of the traits...