"Raw materials were not an issue" for the evolution of the first life on earth, argues Henderson Cleaves, a researcher at the Carnegie Institution, quoted in Carl Zimmer's Science essay on origins of life research (subscription required for full text). There is good reason to believe that there were plenty of organic compounds floating around on the earth 4 billion years ago. The big problem, as Zimmer notes, is how you get from the primordial soup, Darwin's "warm little pond", to an organized, self-reproducing system.

A key point to keep in mind when reading about this subject is that scientists will probably never reconstruct just how life on Earth first arose, but that question, a historical one, is not the most interesting one from a biologist's perspective. The real question is how could life have arisen from non-living constituents. The answer to that question, unlike the more narrow question about the history of life on this planet, has implcations for how we understand the potential for life throughout the universe.

One more key point is that the goal here is not to simply speculate about how life could first arise from non-life; the goal is to know which ideas are right by actually producing life and its precursors in the lab. Zimmer describes scientists who are attempting to do just that. As we celebrate Darwin this year, inevitably the clash between evolution and creationism is going to be in the headlines (the first state anti-evolution bill is already out in Oklahoma, running under the guise of academic freedom). This clash, for the last 50 years or so and especially since the rise of Intelligent Design, has been billed as a conflict between two competing scientific theories, but in fact only one of them is science. Only one of these is a scientific theory, one that has driven thousands of scientists to head out into the field or the lab and make observations to test their detailed, specific ideas.

That is Darwin's greatest legacy: he didn't simply speculate about where the diversity of life on Earth came from, he didn't simply comment on one or another authority about how life develops; he laid out some clear, falsifiable ideas and set out to test those ideas against what can really be observed in nature. That's the great strength of the scientific method. What we're celebrating in the Year of Darwin is 150 years of great science.