On the Misidentification of Species: Sampling Error in Primates and Other Mammals Using Geometric Morphometrics in More Than 4000 Individuals

An accurate classification is the basis for research in biology. Morphometrics and morphospecies play an important role modern taxonomy, with geometric morphometrics increasingly applied as a favourite analytical tool. Yet, really large samples are seldom available species even less common palaeontology, where often identified, described compared using just one or very few specimens. The impact of sampling error how sample must be to mitigate inaccuracy questions taxonomy. Using more than 4000 crania adult mammals taxa representing each four placental superorders, we assess impacts on estimates means, variances covariances Procrustes shape data resampling experiments. In group closely related (mostly congeneric), found that can identified fairly accurately when means based relatively small samples, although errors frequent fewer specimens primates prone inaccuracies. A precise reconstruction similarity relationships, contrast, sometimes requires (> 100), but this varies widely depending study group. Medium-sized necessary estimate standard mean shapes intraspecific variance covariance structure, case minimum sizes broadly similar across all groups (? 20–50 individuals). Overall, thus, sized required depends what being assessed, about 25–40 (for sex, if sexually dimorphic) may average adequate attainable size estimating most commonly used parameters. As expected, best predictor effects ratio between- within-species variation: larger ratio, smaller needed obtain same level accuracy. Even though ours largest date uncertainties morphometrics, despite its generally high congruence previous analyses, feel it would premature generalize. Clearly, there no priori answer particular universal recipe control error. Exploratory analyses experiments thus desirable, easy perform yield powerful preliminary clues effect parameter comparative studies morphospecies, variety other morphometric applications biology medicine. Morphospecies descriptions indeed piece provisional evidence much complex evolutionary puzzle. However, they crucial provide complimentary integrative Thus, taxonomy provides bricks biology, understanding robustness these first fundamental step build scientific knowledge sound, stable long-lasting foundations.