id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
work_7dwvpjfk3fhrrfpb4h4vbyrieq	Marshall Abrams	How Do Natural Selection and Random Drift Interact?	2007	23	.pdf	application/pdf	5353	550	58	selection and drift are embodied in these population-level probabilities. as two aspects of probability distributions over frequencies in populations of organisms. Drift is the aspect of such a distribution controlled by population size, while selection is the aspect of the distribution controlled by differences in fitness. the fate of individual organisms, then the distribution over future frequencies in a population will also be causal. though these population-level probabilities are partly controlled by population size and partly controlled by fitness differences.3 This provides a way of natural selection as a force is constituted by fitness differences among individual organisms in a population, where fitnesses are constituted by certain probabilities which are in some sense causal, natural selection and drift are Thus, for example, if the individual level probabilities are propensities, then Pij is the propensity for a population of i A's propensities are dispositions, then population-level probabilities are causal in	./cache/work_7dwvpjfk3fhrrfpb4h4vbyrieq.pdf	./txt/work_7dwvpjfk3fhrrfpb4h4vbyrieq.txt