The Scientific Approach to Evolution: What They Didn't Teach You in Biology by Rob Stadler

Author:Rob Stadler [Stadler, Rob]
Language: eng
Format: azw3, epub
Published: 2016-09-20T16:00:00+00:00

Despite decades of sustained selection in relatively small, sexually reproducing laboratory populations, selection did not lead to the fixation of newly arising unconditionally advantageous alleles. This is notable because in wild populations we expect the strength of natural selection to be less intense and the environment unlikely to remain constant for 600 generations. Consequently, the probability of fixation in wild populations should be even lower than its likelihood in these experiments.

To paraphrase the results, the study authors found no advantageous genetic changes that were preferentially selected and had thus became predominant in the genome. This result was surprising, because the authors’ artificial form of selection in a controlled laboratory was stronger, more consistent, and more focused than the types of selection that occur in the wild. As such, the experimental conditions were a best-case scenario for evolution, but the authors observed nothing significant.

One could argue that 600 generations is not enough. This would only translate to roughly 10,000 years of human evolution. Fortunately, some bacteria reproduce about 100 times as fast as fruit flies, so in a similar expanse of time we could study 60,000 generations in order to find high-confidence evidence of evolution. For this, we have Richard Lenski to thank.

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