Punctuated Equilibria and 100 Year Floods
Here’s what I mean: “100 year flood” refers to the probability of a flood of a certain size happening not once in a hundred years, but its probability of occuring within a given timeframe. So, within a given year, there is a certain probability of there being a flood the size of a “100 year flood”. This is opposed to the idea that a flood of such size will occur once within the period of a hundred years.
Punctuated equilibria, on the other hand, refers to rates of evolution and speciation. If speciation occurs more in fits and starts rather than through a more gradualistic model, then the number of species existant exists in an equilibria punctuated by sudden change.
One clear difference between the two ideas is that one is impacted by biological evolution and the other is impacted by climatic and meterological factors. I unfortunately do not have the keenest grasp on probability theory or statistics, but I suspect a similarity there. Rates of speciation refer to change amongst populations of organisms impacted by a variety of factors, climate amongst them. This concept importantly involves population thinking, but also “tree thinking” as described by Robert O’Hara in a paper here. The crux of the difference between 100 year floods and punctuated equilibria (aside from the disperate phenomena they seek to characterize) may be that, as of yet, the mechanisms governing speciation and climate are too different. Rates of speciation and recurrance intervals of floods both importantly concern the history of the phenomenon under consideration and use this to guide probabilistic descriptions of rates and recurrance, but ultimately the phenomena and mechanisms that impact the phenomena may be too different from one another.