Premium
Niche conservatism and species richness patterns of squamate reptiles in eastern and southern Africa
Author(s) -
MORALESCASTILLA IGNACIO,
OLALLATÁRRAGA MIGUEL Á.,
BINI LUIS MAURICIO,
DE MARCO JR PAULO,
HAWKINS BRADFORD A.,
RODRÍGUEZ MIGUEL Á.
Publication year - 2011
Publication title -
austral ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.688
H-Index - 87
eISSN - 1442-9993
pISSN - 1442-9985
DOI - 10.1111/j.1442-9993.2010.02186.x
Subject(s) - species richness , niche , ecology , range (aeronautics) , temperate climate , ecological niche , arid , geography , conservatism , macroecology , biology , habitat , materials science , politics , political science , law , composite material
Niche conservatism has been proposed as a mechanism influencing large‐scale patterns of taxonomic richness. We document the species richness patterns of five monophyletic squamate reptile groups (gekkonids, cordylids‐scincids, lacertids, chameleons and alethinophidian snakes) in eastern and southern Africa, and explore if observed patterns reflect niche conservatism processes. We quantified richness and its relationships with current climatic conditions by gridding species' range maps at 110 × 110 km. Also, dated phylogenies and palaeoclimatic reconstructions, coupled with evidence from the fossil record, were used to approximate the areas and climate characteristics in which each group originated and/or radiated. Mean species richness and geographically corrected confidence intervals in current climate types were calculated for each group in order to establish their climatic preferences. On average, the species richness of older groups (gekkonids, cordylids‐scincids and lacertids) was lower in equatorial climates and higher in arid and temperate conditions, whereas more recent groups (chameleons and alethinophidian snakes) were richer in equatorial and temperate climates and less rich in arid conditions. Across all groups, higher richness was associated with climatic characteristics similar to those prevailing at the time in which each group originated/radiated. The congruence of the current climates where reptile groups are richer and the past climates amidst which those groups originated is consistent with an explanation for their diversity gradients based on niche conservatism.