Summary1. We present mvMORPH, a package of multivariate phylogenetic comparative methods for the R statistical environment. mvMORPH is freely available on the CRAN package repository (http://cran.r-project.org/web/packages/ mvMORPH/). 2. mvMORPH allows fitting a range of multivariate evolutionary models under a maximum-likelihood criterion. Initially developed in the context of phylogenetic analysis of multiple morphometric traits, its use can be extended to any biological data set with one or multiple covarying continuous traits. All the fitting models include the possibility to use SIMMAP-like mapping, which may be useful for fitting changes along lineages at a given point in time. All models provide diagnostic metrics for convergence and reliability of estimates, as well as the possibility to include trait measurement errors in model estimates. 3. New features provided by the mvMORPH package include the possibility of fitting models with changes in the mode of evolution along the phylogeny, which will be particularly meaningful in comparative analyses that include extinct taxa, for example when testing changes in evolutionary mode associated with global biotic/abiotic events. 4. We briefly describe the models already included in mvMORPH and provide some demonstration of the use of the package with two simulated worked examples.

The oxygen isotope composition of human phosphatic tissues (delta18OP) has great potential for reconstructing climate and population migration, but this technique has not been applied to early human evolution. To facilitate this application we analyzed delta18OP values of modern human teeth collected at 12 sites located at latitudes ranging from 4 degrees N to 70 degrees N together with the corresponding oxygen composition of tap waters (delta18OW) from these areas. In addition, the delta18O of some raw and boiled foods were determined and simple mass balance calculations were performed to investigate the impact of solid food consumption on the oxygen isotope composition of the total ingested water (drinking water+solid food water). The results, along with those from three, smaller published data sets, can be considered as random estimates of a unique delta18OW/delta18OP linear relationship: delta18OW=1.54(+/-0.09)xdelta18OP-33.72(+/-1.51)(R2=0.87: p [H0:R2=0]=2x10(-19)). The delta18O of cooked food is higher than that of the drinking water. As a consequence, in a modern diet the delta18O of ingested water is +1.05 to 1.2 per thousand higher than that of drinking water in the area. In meat-dominated and cereal-free diets, which may have been the diets of some of our early ancestors, the shift is a little higher and the application of the regression equation would slightly overestimate delta18OW in these cases.