Chapter 2 - Phylogenetic Character Reconstruction

Abstract

Comparisons among the features of living organisms have played a prominent role in the biological sciences at least since the time of Aristotle. The comparative approach takes advantage of the enormous diversity of organismal form and function to study basic biological processes of physiology, embryology, neurology, and behavior. From an evolutionary perspective, interspecific (between species) comparisons allow for the systematic study of organismal design. Recent years have seen great advances in the formulation of comparative methods to estimate or infer ancestral phenotypes from extant (living) species. This article summarizes the major recent developments in phylogenetically based methods of studying character evolution, with the goals of explaining both the strengths and weaknesses of alternative methods. Most of the empirical examples cited are among animals with the most complex central nervous systems (e.g., vertebrates) in which neurological and behavioral evolution has been (arguably) most extensively studied. A major goal of this article is to highlight some of the most exciting new developments in the study of character evolution now being explored in this fascinating area of comparative neurobiology.