1 Natural History Museum of Denmark, Natural History Museum of Denmark, Faculty of Science, Københavns Universitet2 UPMC University Paris 06, Paris3 Canterbury Museum4 Museum of New Zealand Te Papa Tongarewa5 Natural History Museum of Denmark, Natural History Museum of Denmark, Faculty of Science, Københavns Universitet
The presence of a phylogenetic signal in the variation of osteohistological features has been recently debated in the literature. Previous studies have found a significant signal for some features, but these results were obtained on a small amount of characters and a reduced sample. Here we perform a comprehensive study in which we quantify the phylogenetic signal on 62 osteohistological features in an exhaustive sample of palaeognathous birds. We used four different estimators to measure phylogenetic signal – Pagel’s λ, Abouheif’s Cmean, Blomberg’s K, and Diniz-Filho’s phylogenetic eigenvector regressions PVR – and four topologies taken from the literature. Bone size and bone vascular density exhibit a strong phylogenetic signal, whereas all but four of the remaining features measured at the histological level – cellular size in caudal and medial transects of femora, and proportion of oblique vascular canals in rostral and caudal transects of tibiotarsi – exhibit a weaker signal. We also found that the impact of the topologies used in the analyses is very low compared with that of sample size. We conclude that the analysis of a comprehensive sample is crucial to obtain reliable quantifications of the phylogenetic signal.