Brain and body size are highly correlated across the mammalian Order Carnivora, and are also correlated with many life history traits and ecological variables. While most of these are difficult or impossible to observe in the fossil record, they would provide valuable insight into the biology of early carnivorans. The subgroup Caniformia, which includes dogs, bears, skunks, raccoons, weasels, and other related species, possesses a large living diversity, a good fossil record, and well-resolved set of evolutionary relationships. Deriving body and brain size data from the fossil record for these species will allow two hypotheses of evolutionary trends to be addressed. First, what are the underlying dynamics of the evolutionary trends that produce the modern distribution of brain and body sizes? Second, if modern body size distributions are the result of parallel trends, is there an evolutionary control on brain size relative to body size, and has this remained constant through time?
This investigation will be of general interest to biologists, as it will offer insight into the ecology and biology of early caniform species. In addition, if biological constraints are uncovered an analysis of changing relative brain size through time could have implications for the study of developmental biology. In addition, the mathematical and statistical methods necessary to interpret these data should be broadly applicable to many areas of the life sciences, especially studies seeking to parameterize count data or allometries.
