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The diversity of life is ultimately generated by evolution, and much attention has focused on the rapid evolution of ecological traits. Yet, the tendency for many ecological traits to instead remain similar over time [niche conservatism (NC)] has many consequences for the fundamental patterns and processes studied in ecology and conservation biology. Here,(More)
Mountains are centres of global biodiversity, endemism and threatened species. Elevational gradients present opportunities for species currently living near their upper thermal limits to track cooler temperatures upslope in warming climates, but only if changes in precipitation are sufficiently in step with temperature. We model local population extirpation(More)
Elevational gradients hold enormous potential for understanding general properties of biodiversity. Like latitudinal gradients, the hypotheses for diversity patterns can be grouped into historical explanations, climatic drivers, and spatial hypotheses. The spatial hypotheses include the species-area effect and spatial constraint (mid-domain effect null(More)
A latitudinal gradient in biodiversity has existed since before the time of the dinosaurs, yet how and why this gradient arose remains unresolved. Here we review two major hypotheses for the origin of the latitudinal diversity gradient. The time and area hypothesis holds that tropical climates are older and historically larger, allowing more opportunity for(More)
The elevational gradient in plant and animal diversity is one of the most widely documented patterns in ecology and, although no consensus explanation exists, many hypotheses have been proposed over the past century to explain these patterns. Historically, research on elevational diversity gradients has focused almost exclusively on plant and animal taxa.(More)
Biologists have long searched for mechanisms responsible for the increase in species richness with decreasing latitude. The strong correlation between species richness and climate is frequently interpreted as reflecting a causal link via processes linked to energy or evolutionary rates. Here, we investigate how the aggregation of clades, as dictated by(More)
The extinction of dinosaurs at the Cretaceous/Paleogene (K/Pg) boundary was the seminal event that opened the door for the subsequent diversification of terrestrial mammals. Our compilation of maximum body size at the ordinal level by sub-epoch shows a near-exponential increase after the K/Pg. On each continent, the maximum size of mammals leveled off after(More)
In 1967, Daniel Janzen proposed the influential, but largely untested hypothesis, that tropical mountain passes are physiologically higher than temperate mountains. I test his key prediction, the one upon which all the others rely: namely, that elevational range sizes of organisms get larger on mountains at increasing latitudes. My analyses use 170 montane(More)
Aim The global species richness patterns of birds and mammals are strongly congruent. This could reflect similar evolutionary responses to the Earth's history, shared responses to current climatic conditions, or both. We compare the geographical and phylogenetic structures of both richness gradients to evaluate these possibilities. Methods Gridded bird and(More)
The Metabolic Theory of Ecology (MTE) posits that the temperature-dependent kinetics of metabolism shape broad-scale patterns of biodiversity. Here we test whether the MTE accounts for patterns of diversity using 102 elevational diversity gradients of reptiles and amphibians. In particular, we examined the support for the two key predictions of the MTE:(More)