Selection and covariance

Price's 1970 covariance identity is the starting point for the one-generation decomposition we apply in dalla2026between, partitioning change in any encoding trait into a selection covariance with fitness and a transmission term, and specialising to Bayes risk in our Price-for-risk theorem.

riva2026task applies Price's selection-covariance equation directly to derive how lineage selection acts on the ecology-injection trait, with part (a) of the recipe-trait proposition reproducing the covariance identity. The cite supplies the formal backbone of the selection result on post-training strength.