Arkady
President
This is only a "political" post because we live in a country where there are, bizarrely, still ongoing political fights about teaching evolution. But, regardless, it's really fascinating. It details an experiment that mapped the evolution of the ability to consume citrate in e coli bacteria over the course of a quarter-century-long experiment:
http://scienceblogs.com/loom/2008/06/02/a-new-step-in-evolution/
Because of the way the experiment was designed, scientists can go back and check, step by step, how the new ability evolved, both in terms of the population dynamics of that trait taking over a colony through the course of many generations, and in terms of the genetics of how the new ability was actually constructed from infinitesimally small random mutations, which accumulated through the non-random process of natural selection.
Unfortunately, because generations for most larger species are so long, you couldn't perform a similar experiment on, say, mice, to watch them evolve the ability to fly. While you can have 44,000 generations of bacteria in just a quarter century, even for a fast-breeding, short-lived mammal like a mouse, if you'd started the experiment at the dawn of civilization and run it to today, you'd be lucky to have had that many generations. Ultimately, I assume we'll rely on supercomputers with simulated evolution to work out the exact mechanics of evolution for larger, more complex life. But for now, we at least have a clear proof of concept, in a lab, to go with the mountains of other data from things like the fossil record, comparative anatomy, population gene studies, and so on.
http://scienceblogs.com/loom/2008/06/02/a-new-step-in-evolution/
Because of the way the experiment was designed, scientists can go back and check, step by step, how the new ability evolved, both in terms of the population dynamics of that trait taking over a colony through the course of many generations, and in terms of the genetics of how the new ability was actually constructed from infinitesimally small random mutations, which accumulated through the non-random process of natural selection.
Unfortunately, because generations for most larger species are so long, you couldn't perform a similar experiment on, say, mice, to watch them evolve the ability to fly. While you can have 44,000 generations of bacteria in just a quarter century, even for a fast-breeding, short-lived mammal like a mouse, if you'd started the experiment at the dawn of civilization and run it to today, you'd be lucky to have had that many generations. Ultimately, I assume we'll rely on supercomputers with simulated evolution to work out the exact mechanics of evolution for larger, more complex life. But for now, we at least have a clear proof of concept, in a lab, to go with the mountains of other data from things like the fossil record, comparative anatomy, population gene studies, and so on.
