The red flowers of the invasive African tulip tree (Spathodea campanulata; Bignoniaceae) stand out in a Puerto Rican rain forest. This species may occupy a mathematical hole, having an ecological strategy unoccupied by other species in the community. Recent mathematical advances now allow detection of holes and better understandings of species invasions and extinctions. Imagine…

Winter in the United Kingdom is quiet. Organisms retreat underground or migrate to less harsh climates. Only simple winter scenes remain, painted in broad figures with a restricted palette of colors. The complexity of summer is temporarily washed away. Fields are seas of black soil, prepared for spring planting. Coastal landscapes are brown, dominated by…