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Latitudinal diversity gradients are first-order expressions of diversity patterns both on land and in the oceans, although the current hypotheses that seek to explain them are based chiefly on terrestrial data. We have assembled a database of the geographic ranges of 3,916 species of marine prosobranch gastropods living on the shelves of the western(More)
Comparison of evolutionary patterns among Late Cretaceous marine bivalves and gastropods during times of normal, background levels of extinction and during the end-Cretaceous mass extinction indicates that mass extinctions are neither an intensification of background patterns nor an entirely random culling of the biota. During background times, traits such(More)
Geographic range has been regarded as a property of species rather than of individuals and thus as a potential factor in macroevolutionary processes. Species durations in Late Cretaceous mollusks exhibit statistically significant positive relationships with geographic range, and the attainment of a typical frequency distribution of geographic ranges in the(More)
Scale and hierarchy must be incorporated into any conceptual framework for the study of macroevolution, i.e. evolution above the species level. Expansion of temporal and spatial scales reveals evolutionary patterns and processes that are virtually inaccessible to, and unpredictable from, short-term, localized observations. These larger-scale phenomena range(More)
The Cambrian explosion is named for the geologically sudden appearance of numerous metazoan body plans (many of living phyla) between about 530 and 520 million years ago, only 1.7% of the duration of the fossil record of animals. Earlier indications of metazoans are found in the Neoproterozic; minute trails suggesting bilaterian activity date from about 600(More)
Global diversity curves reflect more than just the number of taxa that have existed through time: they also mirror variation in the nature of the fossil record and the way the record is reported. These sampling effects are best quantified by assembling and analyzing large numbers of locality-specific biotic inventories. Here, we introduce a new database of(More)
The latitudinal diversity gradient, with maximum taxonomic richness in the tropics, is widely accepted as being pervasive on land, but the existence of this pattern in the sea has been surprisingly controversial. This is partly due to Thorson's influential claim that the normal latitudinal diversity gradient occurs in marine epifauna (taxa living on the(More)
The evolutionary dynamics underlying the latitudinal gradient in biodiversity have been controversial for over a century. Using a spatially explicit approach that incorporates not only origination and extinction but immigration, a global analysis of genera and subgenera of marine bivalves over the past 11 million years supports an "out of the tropics"(More)
Biotic responses to Pleistocene climatic fluctuations have traditionally been analyzed in the context of glacial-interglacial cycles on the scale of 10000-100 000 years. However, emerging evidence indicates that short-term, high-amplitude, climatic 'flickers', close to the limits of the resolving power of the fossil record, occurred within the glacial and(More)
For many current issues in macroevolution and macroecology, it is important to know to what degree the attributes of species are shared among closely related lineages, a concept sometimes referred to as species-level heritability. Recently, Webb and Gaston proposed a new method for analyzing the heritability of geographic range size and concluded that range(More)