Punctuated equilibrium is a theory of speciation proposed by Niles Eldredge and Stephen Jay Gould in 1972. The problem it was designed to solve is straightforward: the fossil record doesn’t show what Darwin’s theory predicts. Which makes sense, of course, now that we’ve proven beyond any shadow of a reasonable doubt that evolution by natural selection is mathematically impossible, never happened, and could not possibly happen. Something that never took place doesn’t leave evidence behind.
And yet, there is obviously evidence of something. So instead of the slow, gradual transitions from one species to another that classical evolutionary theory requires, what the rocks appear to show is species appearing abruptly, persisting unchanged for millions of years, and then suddenly being replaced by other species that also appear just as quickly. Gould and Eldredge proposed that this fossil pattern is meaningful, is not just an artifact of incomplete fossilization, and that speciation happens rapidly in small, isolated populations mutating rapidly under strong natural selection pressure. The result of the rapid mutations result in a burst of dramatic change in a few thousand years, followed by millions of years of stasis when the strong selection pressure abates.
They called this process Punctuated Equalibrium and it rapidly became one of the most influential ideas in evolutionary biology. For fifty years it has served as the standard explanation for why the fossil record looks the way it does. However, in the process of analyzing the data to figure out why the scientists sequencing the E. coli generations were playing it so coy with the average number of fixations per generation for the MITTENS 3.0 paper, a thought occurred to me: if half the populations subjected to very strong artificial pressure were developing genomic cancer, then what were the probabilities required for a species under sufficient selection pressure to speciate in a punctuated manner that would avoid the cancer and the subsequent inevitable extinction?