Mourguiart Philippe. (2000). Historical changes in the environment of lake Titicaca : evidence from ostracod ecology and evolution. Advances in Ecological Research, 31, p. 497-520. ISBN 0-12-013931-6.
Titre du document
Historical changes in the environment of lake Titicaca : evidence from ostracod ecology and evolution
Année de publication
2000
Type de document
Article
Auteurs
Mourguiart Philippe
Source
Advances in Ecological Research, 2000,
31, p. 497-520 ISBN 0-12-013931-6
Lake Titcaca is a high-altitude, nearly closed, basin lake in the tropical belt of South America. The lake is subjected to the influence of the intertropical convergence zone (ITCZ) during the summer months, and is characterized by a flora and fauna that, while not as diverse as that of many other ancient lakes, nevertheless has groups such as molluscs and ostracods which show a fascinating ecological and morphological variability (polymorphism). For these and other groups, Lake Titicaca is an ideal natural laboratory for studies of evolution. This chapter demonstrates how, by applying transfer functions to quantitative information on the response of extant ostracod communities to habitat heterogeneity and environmental variability, past environments of Lake Titicaca can be reconstructed. Results show the recent history of Titicaca (since 8000 14C years bp) to have been characterized by major lake-level fluctuations which separated the basin into three palaeolakes at various intervals of geological time, and which have possibly influenced population dynamics in the lake for groups such as fishes, molluscs and ostracods. The high-amplitude palaeoenvironental variations indicated by the transfer function also seem to have had important effects on the dynamics of ostracod populations. Special attention is given to the formation of habitats and evolution of the lake ecosystem during the past 10 000 years, with particular emphasis on the ostracod crustaceans within the subfamily Limnocytherinae, a key ostracod group in the central Andes, and their highly variable carapace morphology. It is possible to distinguish among several morphs (or subspecies ?) within this group but the overlap is significant and individuals are sometimes difficult to classify... (D'après résumé d'auteur)
