The peacock’s tail presented a problem for Charles Darwin.  It clearly could not have arisen by natural selection. Its beauty, extravagance, and most of all, its impracticality seemed to argue against the gradual increase, generation after generation, of such a structure within a population. Darwin introduced a separate process, sexual selection, to explain the origin… (read more)

Dr. Pangloss in Voltaire’s Candide is famous for seeing how everything fit perfectly together.  Everything is for the best in the best of all possible worlds!  Most of us have more difficulty in seeing the relationships between living individuals and their environment.  This is especially true when many biological traits or environmental measures are involved. To… (read more)

Natural selection describes how small variations in plants and animals lead to the remarkable fit between their traits and the environments they live in.  It does not, however, always work. The limits to natural selection receive less attention than the potential it has to explain all manner of adaptation and diversity.  I argue here that… (read more)

Biodiversity is one of life’s great perks.  Whether your interests run to gardening, woodworking, wine tasting, or hiking, the variety of life forms all around us enriches and sustains our lives as humans.  The variety in our diets, in the landscapes that surround us, in the medicines that heal us and in the works of… (read more)