title: [Toward exploration of morphological diversity of measurable traits of mammalian skull. 2. Scalar and vector parameters of the forms of group variation].
abstract: Any morphospace is partitioned by the forms of group variation, its structure is described by a set of scalar (range, overlap) and vector (direction) characteristics. They are analyzed quantitatively for the sex and age variations in the sample of 200 skulls of the pine marten described by 14 measurable traits. Standard dispersion and variance components analyses are employed, accompanied with several resampling methods (randomization and bootstrep); effects of changes in the analysis design on results of the above methods are also considered. Maximum likelihood algorithm of variance components analysis is shown to give an adequate estimates of portions of particular forms of group variation within the overall disparity. It is quite stable in respect to changes of the analysis design and therefore could be used in the explorations of the real data with variously unbalanced designs. A new algorithm of estimation of co-directionality of particular forms of group variation within the overall disparity is elaborated, which includes angle measures between eigenvectors of covariation matrices of effects of group variations calculated by dispersion analysis. A null hypothesis of random portion of a given group variation could be tested by means of randomization of the respective grouping variable. A null hypothesis of equality of both portions and directionalities of different forms of group variation could be tested by means of the bootstrep procedure.
authors.forename: A A
authors.initials: AA
authors.lastname: Lisovskiĭ
authors.forename: I Ia
authors.initials: IIa
authors.lastname: Pavlinov
mesh_terms: D000367:Age Factors; D000818:Animals; D044822:Biodiversity; D002508:Cephalometry; D005260:Female; D008297:Male; D008962:Models, Theoretical; D045969:Mustelidae / Q000033:anatomy & histology*; D012737:Sex Factors; D012886:Skull / Q000033:anatomy & histology*; D013045:Species Specificity