Reproductive innovations and pulsed rise in plant complexity

Abstract

Evolutionary pulses of complexity The evolution of land plants has been marked by an increase in the complexity of reproductive structures. Leslie et al . analyzed the temporal pattern of this increase in a study of fossil and extant land plants across the entire paleontological record. Reproductive complexity increased in two widely separated pulses corresponding to key innovations in reproductive biology: the origin of seeds in the very late Devonian and the origin of flowering plants in the mid-Cretaceous almost 250 million years later. After the origin of flowers, there was a rapid expansion in the morphological complexity of flowering plants. In contrast to many aspects of animal morphological diversity, which expanded early in evolutionary history, most complexity in plants was achieved relatively late. —AMS