0000000000699578
AUTHOR
David J. Horne
Palaeoclimatic applications of large databases: developing and testing methods of palaeotemperature reconstruction using nonmarine ostracods
Non-analogue methods for Quaternary palaeoclimatic reconstruction, such as the coleopteran Mutual Climate Range method and the Mutual Ostracod Temperature Range (MOTR) method, use large geographical databases combined with modern climate datasets to establish the modern climate/temperature ranges of species, which can then be applied to the interpretation of fossil assemblages. Such approaches have been criticized for their lack of attention to variation in the distributions of species within their climate ranges. The MOTR method, for example, assumes that a species has an equal probability of occurring anywhere within its temperature range (e.g. mean July air temperature range), but tests …
Mutual Climatic Range Methods for Quaternary Ostracods
Abstract The development of Mutual Climatic Range (MCR) methods for ostracods has included the estimation of marine bottom-water palaeotemperatures, but it has focused mainly on the use of non-marine ostracods to infer past air temperatures. The Delorme analogue MCR method, using only those components of a fossil assemblage that co-exist today, has yielded mean annual air temperature and annual precipitation estimates for North American Quaternary sites. The Mutual Ostracod Temperature Range (MOTR) non-analogue MCR method utilises all species in a fossil assemblage; calibrations based on a European database have been applied to the estimation of mean July and January air temperatures for En…
Linking present environment and the segregation of reproductive modes (geographical parthenogenesis) in Eucypris virens (Crustacea: Ostracoda)
Aim Geographical parthenogenesis – in which parthenogenetic populations are more widely distributed than sexually reproducing populations – is observed in many plant and animal species. Many hypotheses have been proposed to account for this biogeographical pattern, and these often invoke historical processes such as the influence of glaciation. However, there are relatively few empirical studies of the contemporary factors associated with geographical parthenogenesis. The aim of this study was to understand its causes by linking contemporary environmental gradients with reproductive modes in the freshwater ostracod Eucypris virens. Location Europe and North Africa. Methods We sampled popula…