NEW MODEL SYSTEMS FOR STUDYING THE EVOLUTIONARY BIOLOGY OF AGING - CRUSTACEA

Progress in any area of biology has generally required work on a varie ty of organisms. This is true because particular species often have ch aracteristics that make them especially useful for addressing specific questions. Recent progress in studying the evolutionary biology of se nescence has been made through the use of new species, such as Caenorh abditis elegans and Drosophila melanogaster, because of the ease of wo rking with them in the laboratory and because investigators have used theories for the evolution of aging as a basis for discovering the und erlying mechanisms. I describe ways of finding new model systems for s tudying the evolutionary mechanisms of aging by combining the predicti ons of theory with existing information about the natural history of o rganisms that are well-suited to laboratory studies. Properties that m ake organisms favorable for laboratory studies include having a short generation time, high fecundity, small body size, and being easily cul tured in a laboratory environment. It is also desirable to begin with natural populations that differ in their rate of aging. I present thre e scenarios and four groups of organisms which fulfill these requireme nts. The first two scenarios apply to well-documented differences in a ge/size specific predation among populations of guppies and microcrust acea. The third is differences among populations of fairy shrimp (Anos traca) in habitat permanence. In all cases, there is an environmental factor that is likely to select for changes in the life history, inclu ding aging, plus a target organism which is well-suited for laboratory studies of aging.