tailieunhanh - Reproductive compensation

Some female respondents had accessed PMTCT services when pregnant. Among women not on ART, knowledge of PMTCT and where to obtain services was poorer. Women perceived PMTCT counselling on infant feeding, contraception, and dual protection to be inadequate. Many women not receiving ART knew that antiretroviral drugs were available at the clinics they were attending and knew that they did not yet qualify for the drugs. They knew little of the health effects of the therapy, however. Their knowledge appeared to be acquired from the community and was limited to vague statements regarding “improved health.” Men not on. | doi Reproductive compensation PATRICIA ADAIR GOWATY Department of Ecology and Evolutionary Biology 621 Charles E. Young Drive University of California Los Angeles 90095 USA and The Smithsonian Tropical Research Institute Unit 0948 APO AA 34002-0948 USA Keywords constraints differential allocation hypothesis dispersal limitation life history trade-offs mate preferences offspring viability selection phenotypic plasticity sexual coercion. Abstract The reproductive compensation hypothesis says that individuals constrained by ecological or social forces to reproduce with partners they do not prefer compensate for likely offspring viability deficits. The reproductive compensation hypothesis assumes that i pathogens and parasites evolve more rapidly than their hosts ii mate preferences predict variation in health and viability of offspring iii social and ecological factors keep some individuals from mating with their preferred partners some are constrained to mate with partners they do not prefer iv all individuals may be induced to compensate so that v variation in compensation is due to environmental and developmental factors affecting between-individual abilities to express compensatory mechanisms. Selection favouring compensation may act through variation in prezygotic physiological mechanisms zygotic mechanisms or parental care to eggs or young that enhance offspring health increasing the likelihood that some offspring survive to reproductive age often at a survival cost to the parents. Compensation may be through increased number of eggs laid or offspring born a compensatory effort working during a single reproductive bout that sometimes will match the number of offspring surviving to reproductive age produced by unconstrained parents during the same bout. The reproductive compensation hypothesis therefore predicts trade-offs in components of fitness for breeders such that parents constrained to mating with a nonpreferred partner but