POPULATION GENETIC STRUCTURING IN ISOPODS: HISTORICAL AND ECOLOGICAL DETERMINANTS

摘要: Isopods are crustaceans that show a wide adaptive radiation. They inhabit benthic marine and freshwater envi-ronments, parasites of fishes, have colonized terrestrial habitats. an extraor¬dinary diversification in adaptations, coinciding with equally diverse array different degrees stenoecy, char¬acterizing individual species. Among isopods, trichoniscids very limited dispersal ability. This is mainly due to physiological constraints necessitate them humid edafic environments, subterranean Results from genetic surveys revealed variability ranges spec¬trum, high degree specific structure often detectable (Gentile & Sbordoni, 1998; Gentile et al. Allegrucci, submitted; Cobolli Sbordoni al., 1997). Thus, valuable tool study the inter- intrapopulation components variation, allowing researcher detect action evolutionary factors as drift, selection, gene flow, separately. In this communication we discuss some case studies which it has been possible relate observed historical ecological factors. Centile. C. V. Sbordoni. 1998. Evolution 52: press. Gentile, G.. S. Sarbu, M. Menichetti 4 Galdenzi. In: H. Wilkens (ed.). Ecosystems World. press. Cobolli M.. Ketmaier. E. De Matthaeis Taiti. 1997. Heredity. 79: 463-472.