Tempo and mode in evolution of complex organisms.

Author(s): Bokma F

Summary:

Most evolutionary biologists appear to believe that populations and species are well adapted to their environment, as the result of continuous action of natural selection on all their traits. In complex organisms, however, many traits do not experience the outside environment: their environment consists of other traits. This implies that fitness is not determined exclusively by how well traits fit the external environment, but also by how well traits are adapted to each other. I will discuss whether the existence of co-adapted trait complexes may determine the tempo and mode in the evolution of their component traits, and discuss how we could distinguish the extrinsic and intrinsic components of fitness in phylogenetic and experimental studies.