Marshall Abrams (University of Alabama, Birmingham)
I argue that biological evolution and other complex processes depend on imprecise chances, i.e. imprecise analogues of real-valued objective probabilities. I give a general argument for the existence of imprecise chances in nature. I then argue that natural selection, whether involving imprecise chances or not, would give rise to organisms whose behavior was imprecisely chancy. This behavior would then be part of the environment of other organisms in ways that would the make latter's evolution imprecisely chancy. Thus evolution sometimes involves imprecise chance. I explain why the absence of reports of imprecise chance in evolution is nevertheless unsurprising.
