Comparison of environmental inference approaches for ecometric analyses: Using hypsodonty to estimate precipitation

Ecometrics is the study of community-level functional trait-environment relationships. We use ecometric analyses to estimate paleoenvironment and to investigate community-level functional changes through time.
We evaluate four methods that have been used or have the potential to be used in ecometric analyses for estimating paleoenvironment to determine whether there have been systematic differences in paleoenvironmental estimation due to choice of the estimation method. Specifically, we evaluated linear regression, polynomial regression, nearest neighbor, and maximum likelihood methods to explore the predictive ability of the relationship for a well-known ecometric dataset of mammalian herbivore hypsodonty metrics (molar tooth crown to root height ratio) and annual precipitation. Each method was applied to 43 Pleistocene fossil sites and compared to annual precipitation from global climate models. Sites were categorized as glacial or interglacial, and paleoprecipitation estimates w...