Lottery principle

Categories: Biology stubs | Biological reproduction

The lottery principle is the term for a theory about why sexual reproduction is so widespread, introduced in 1975 by George C. Williams, a biology professor at Princeton University.

Sexual reproduction has many drawbacks, since it requires far more energy than asexual reproduction, and there is some argument about why so many species use it.

William used lottery tickets as an analogy for his theory. He argued that asexual reproduction, which produces little or no genetic variety in offspring, was like buying a large number of tickets that all have the same number, limiting the chance of "winning" - that is, surviving. Sexual reproduction, he argued, was like purchasing fewer tickets but with a greater variety of numbers and therefore a greater chance of success.

The point of this analogy is that since asexual reproduction does not produce genetic variations, there is a little ability to quickly adapt to a changing environment. The lottery principle is less accepted these days because of evidence that asexual reproduction is more prevalent in unstable environments, the opposite of what it predicts.