Meeting Abstract
Standing global biodiversity is a product of differential accumulation and loss of lineages through time and across space. Aiming towards a coupled model of factors that promote and suppress the individual components of diversification, origination and extinction, we focus here on the factors underlying lineage loss and its relation to functional diversity in marine bivalves, a model macroevolutionary system. Functional and taxonomic diversity decline in concert along today’s latitudinal gradient from equator to poles. In contrast, functional diversity remained nearly constant through the two mass extinctions that define the Mesozoic and Cenozoic Eras despite a loss of nearly two-thirds of the genus diversity through each episode. This differential response in the two currencies across the latitudinal gradient and the mass extinctions highlights a potential asymmetry in the pressure of diversity-dependent and –independent factors on the biota (e.g. the relative operation of resource-limitation vs. physiology). Similar to the mass extinctions, low-richness functional groups also showed a remarkable resilience to extinction through lower-intensity episodes over the past 65 Myr that appear to correlate with a diversity-independent factor, the rate of temperature change. Exploration of this balance in the operation of diversity-dependent and independent factors on taxonomic and functional diversity now has a sense of urgency given the rising intensity of biodiversity loss in today’s oceans.
