ancestral state reconstruction. During the dry season, the diets of the 13 species of Galapagos finches may be assorted into three broad diet categories, first those that consume grain-like foods are considered "granivores", those that ingest arthropods are termed "insectivores" and those that consume vegetation are classified as "folivores". Dietary ancestral state reconstruction using maximum parsimony recover 2 major shifts from an insectivorous state: one to granivory, and one to folivory. Maximum-likelihood ancestral state reconstruction recovers broadly similar results, with one significant difference: the common ancestor of the tree finch (Camarhynchus) and ground finch (Geospiza) clades are most likely granivorous rather than insectivorous (as judged by parsimony). In this case, this difference between ancestral states returned by maximum parsimony and maximum likelihood likely occurs as a result of the fact that ML estimates consider branch lengths of the phylogenetic tree. Morphological and physiological character evolution Phrynosomatid lizards show remarkable morphological diversity, including in the relative muscle fiber type composition in their hindlimb muscles. Ancestor reconstruction based on squared-change parsimony (equivalent to maximum likelihood under Brownian motion character evolution) indicates that horned lizards, one of the three main subclades of the lineage, have undergone a major evolutionary increase in the proportion of fast-oxidative glycolytic fibers in their iliofibularis muscles. Mammalian body mass In an analysis of the body mass of 1,679 placental mammal species comparing stable models of continuous character evolution to Brownian motion models, Elliot and Mooers showed that the evolutionary process describing mammalian body mass evolution is best characterized by a stable model of continuous character evolution, which accommodates rare changes of large magnitude. Under a stable model, ancestral mammals retained a low body mass through early diversification, with large increases in body mass coincident with the origin of several Orders of large body massed species (e.g. ungulates). By contrast, simulation under a Brownian motion model recovered a less realistic, order of magnitude larger body mass among ancestral mammals, requiring significant reductions in body size prior to the evolution of Orders exhibiting small body size (e.g. Rodentia). Thus stable models recover a more realistic picture of mammalian body mass evolution by permitting large transformations to occur on a small subset of branches. Correlated character evolution Phylogenetic comparative methods (inferences drawn through comparison of related taxa) are often used to identify biological characteristics that do not evolve independently, which can reveal an underlying dependence. For example, the evolution of the