For this meetup we will view a DVD on the Theory of Natural Selection followed by small group discussions. The DVD presentation features Professor Robert Hazen, Clarence Robinson Professor of Earth Science at George Mason University and a research scientist at the Carnegie Institution of Washington's Geophysical Lab. He is the author of many popular books on science and geophysics. In this DVD, Dr. Hazen clearly explains the Theory of Natural Selection in layman terms by going through the few simple points on which Darwin based natural selection. We all know about Darwin observing surprising similarities among different species of tortoises and birds while serving as naturalist aboard the HMS Beagle on its five-year exploring expedition to South America and the Pacific Islands. Shortly after his return in 1836, he formulated his theory of evolution by natural selection, though his revolutionary book, The Origin of Species, was not published until 1859. In that work Darwin describes the process of evolution by natural selection in four easy and understandable observations that Hazan makes clear. Darwin was troubled by the lack of a known physical mechanism for evolutionary change, but discoveries of DNA and the genetic code have now filled in that gap. Debate continues between the gradualist model of evolution, by small incremental changes, and punctuated equilibrium, in which rapid change in a species is followed by long periods of inactivity (stasis). Think of this month's meeting as a primer for February, the month that Darwin is honored!