Richard Lenski of the University of Michigan in East Lansing began a decade-long experiment with Escherichia coli bacteria, allowing them to evolve under constant conditions. By 2010, he had produced more than 50,000 generations. This was the Long-Term Evolution Experiment, which began with 12 strains of Escherichia coli incubated at 37\u00b0C in 12 test tubes. Each morning, a small amount of glucose (25 mg\/L) was added to each tube, which was consumed by the afternoon. The following day, the same amount of each strain was removed from each tube, returned to another tube with a small amount of glucose, and so on. Every 75 days, equivalent to 500 generations of asexual reproduction, a portion of each strain was frozen to create a fossil library of the entire experiment. By 2008, every possible individual mutation had already manifested itself multiple times in the 45,000 generations. Indeed, once, in the 33,127th generation, a mutation with a very low probability also occurs. The same thing happens every day in the world: by calculating the number of E. coli present in the world, we deduce that every possible mutation occurs every day.<\/p>\n","protected":false},"excerpt":{"rendered":"
Richard Lenski of the University of Michigan in East Lansing began a decade-long experiment with…<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[37],"tags":[],"class_list":["post-627772","post","type-post","status-publish","format-standard","hentry","category-fq-en"],"acf":[],"yoast_head":"\n