Evolution in a nutshell
17 August 2008
by
lolife
Filed under
Evolution
From PZ Myers, of course:
Natural selection is such a clear, simple idea that biologists around the world were wacking themselves in the forehead when they read [Darwin's] book, saying, “Of course! Why didn’t I think of that!” He laid out the facts as everybody already knew them, with simple and irrefutible logic leading to an undeniable conclusion. The members of a species exhibit heritable variability; they don’t all look alike. Not all individuals are equally successful at reproducing or surviving, and it is those variants that are best able to live under existing conditions that will leave the most offspring, meaning that the average composition of the next generation will change. Because the forms least able to thrive will not thrive, the population as a whole will slowly drift in the direction of optimality.
The emphasis is mine. Natural selection really is a brilliant and somewhat obvious theory.