Adversity or A-selection favors conservation of adaptation in severe, but stable and predictable, environments. It is contrasted with r- or exploitation selection and K- or interaction selection. The correlates of A-selection (e.g., parthenogenesis, poor migratory ability, long life histories, and low reproductive rates in simple communities in harsh environments) are derived from brief accounts of a genus of tropical log-inhabiting staphylinid beetles and terrestrial invertebrates at high latitudes, the last based on reviews of J. A. Downes. The three selection types are related to each other and the environment by means of T. R. E. Southwood's habitat templet with its two axes, habitat predictability and favorableness. The potential usefulness of the habitat templet when partitioned according to predominant selection process is illustrated by applying it to the evolution of ecological strategies in deserts and the course of decomposition of organic matter.