laxori666 Posted March 11, 2016 Posted March 11, 2016 During the call (e.g. around 19:30), Curtis, the caller, points out how evolution has never been observed in a lab. Stefan rebuts that it's an unreasonable standard of proof because evolution would take too long to be observed in a lab. But actually, evolution has been observed in a lab! Specifically, evolution of bacteria: http://rationalwiki.org/wiki/Lenski_affair . On June 9, 2008, the New Scientist published an article describing preliminary results of a long-running experiment started by Lenski.[2] Lenski and his team had taken a single strain of the bacterium E. coli, separated its descendants into twelve populations,[3] and proceeded to observe their mutations over the course of two decades.[4] The E. coli were fed a measured amount of glucose every day. At one point, one of the populations exploded far beyond the parameters of the experiment. Lenski eventually discovered that this population had evolved the ability to "eat" citrate, an organic molecule which was part of the solution the E. coli lived in, but which E. coli cannot normally uptake. Thus, evolution had been visibly observed, with an exquisite amount of evidence establishing the timeline along the way. Not only that, but the experiment was repeatable; Lenski started new experiments with the frozen "archives" of the population which exploded, and found that beyond a certain point, that particular population of E. coli were highly likely to evolve the ability to digest citrate. The paper also highlighted the role ofhistorical contingency in evolution and the role of potentiating mutations. This is perhaps a bit more interesting an adaptation than humans changing skin color or bird beaks changing shapes or sizes. 4
Boss Posted March 13, 2016 Posted March 13, 2016 I believe the caller was looking for macro-evolution, which would mean observing bacteria becoming anything but bacteria. That is not the case with the experiment you posted.
Guest Gee Posted March 14, 2016 Posted March 14, 2016 I believe the caller was looking for macro-evolution, which would mean observing bacteria becoming anything but bacteria. That is not the case with the experiment you posted. Then he's looking for a few hundred or a few thousand evolutions. A bacteria spontaneously change into a human? Evidence of God thb, but billions upon billions of evolutions, infinetly many evolutions will get you there as well. See if someone thing is true for some infinitesimally small change, then it is true for the sum of infinetly many infinitesimal small changes. (thats actually how some cool stuff is proved in physics and how calculus works) Image the evolutionary path of a species as some sort of curve (path) in (through) some sort of space, the caller wants to see a big discontinuous jump from one part of the curve to another, the difference between two points on the curve. But evolution is going from some starting point and sliding all the way up the curve, going through every point on the curve and summing every point, infinetly many points on the curve, until you get to the end point and then taking the difference between the start and the end point. 1
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