Time Explains Regional Richness Patterns within Clades More Often than Diversification Rates or Area

What Explains Patterns of Diversification and Richness among Animal Phyla?

Animal phyla vary dramatically in species richness (from one species to >1.2 million), but the causes of this variation remain largely unknown. Animals have also evolved striking variation in morphology and ecology, including sessile marine taxa lacking heads, eyes, limbs, and complex organs (e.g., sponges), parasitic worms (e.g., nematodes, platyhelminths), and taxa with eyes, skeletons, limbs...

Absolute diversification rates in angiosperm clades.

The extraordinary contemporary species richness and ecological predominance of flowering plants (angiosperms) are even more remarkable when considering the relatively recent onset of their evolutionary diversification. We examine the evolutionary diversification of angiosperms and the observed differential distribution of species in angiosperm clades by estimating the rate of diversification fo...

More than "more individuals": the nonequivalence of area and energy in the scaling of species richness.

One of the primary ecological hypotheses put forward to explain patterns of biodiversity is known as the more-individuals hypothesis of species-energy theory. This hypothesis suggests that the number of species increases along the global energy gradient primarily as a result of an increase in the total number of individuals that can be supported along that gradient. Implicit in this hypothesis ...

TV nurses often hurt more than heal.

Diversification rates and species richness across the Tree of Life.

Species richness varies dramatically among clades across the Tree of Life, by over a million-fold in some cases (e.g. placozoans versus arthropods). Two major explanations for differences in richness among clades are the clade-age hypothesis (i.e. species-rich clades are older) and the diversification-rate hypothesis (i.e. species-rich clades diversify more rapidly, where diversification rate i...