Table 1 Results of selected phylogenetic Procrustes distance regressions of labyrinth shape ~ independent variables including fossils

From: Independent origin of large labyrinth size in turtles

Model	Variable	Effect	F statistic	Z score	P value	R²	R² model	re-df
~Skull box volume *braincase aspect ratio + labyrinth centroid size	Skull box volume	Allometric	6.365	4.143	0.001	0.040	0.147	133
	Braincase aspect ratio	Spatial constraint	7.118	4.457	0.001	0.045
	Labyrinth centroid size	Allometric	4.403	3.351	0.002	0.028
	Skull box volume: labyrinth centroid size	Interaction	5.396	3.572	0.001	0.034
~Skull box volume *braincase aspect ratio	Skull box volume	Allometric	5.049	3.690	0.001	0.032	0.122	134
	Braincase aspect ratio	Spatial constraint	7.611	4.500	0.001	0.049
	Skull box volume: braincase aspect ratio	Interaction	6.317	3.746	0.001	0.041
~Skull box volume *labyrinth centroid size	Skull box volume	Allometric	7.803	4.340	0.001	0.052	0.112	134
	Labyrinth centroid size	Allometric	5.814	3.888	0.001	0.039
	Skull box volume: labyrinth centroid size	Interaction	3.089	2.349	0.012	0.021
~Braincase aspect ratio	Braincase aspect ratio	Spatial constraint	9.792	4.750	0.001	0.067	0.067	136
~Skull height	Skull height	Allometric	9.533	4.702	0.001	0.066	0.066	136
~Skull box volume	Skull box volume	Allometric	7.266	4.255	0.001	0.051	0.051	136
~Skull length	Skull length	Allometric	6.513	4.073	0.001	0.046	0.046	136
~Skull width	Skull width	Allometric	5.549	3.760	0.001	0.039	0.039	136
~Labyrinth centroid size	Labyrinth centroid size	Allometric	5.299	3.604	0.001	0.037	0.037	136
~Skull box volume + marine.all	Skull box volume	Allometric	6.792	4.022	0.001	0.047	0.058	135
~Skull box volume + marine.all	All extant and extinct marine taxa	Ecological	1.543	1.140	0.125	0.011	0.058	135
~Marine.all	All extant and extinct marine taxa	Ecological	1.963	1.578	0.056	0.014	0.003	136
~Marine.extant	Extant marine taxa	Ecological	0.993	0.287	0.399	0.007	0.005	136
~Freshwater	Freshwater habitat ecology	Ecological	1.500	1.057	0.150	0.001	0.012	136
~Terrestrial	Terrestrial habitat ecology	Ecological	1.351	0.814	0.202	0.010	0.014	136
~Incomplete retraction	No ability to retract neck	Morpho-functional	1.420	0.954	0.182	0.010	0.010	136
~Full retraction	Ability to fully retract neck	Morpho-functional	1.420	0.954	0.182	0.010	0.010	136
~No retraction plane	No preferred plane developed, ancestral anatomy	Morpho-functional	0.341	−1.611	0.945	0.003	0.003	136
~Vertical retraction	Cryptodiran neck anatomy	Morpho-functional	0.235	−2.535	0.999	0.002	0.002	136
~Horizontal retraction	Pleurodiran neck anatomy	Morpho-functional	0.550	−0.980	0.834	0.004	0.004	136

N = 138 for all models. Best model is on top. Hypothesis testing used a phylogenetic Procrustes ANOVA⁸⁹, in which statistical significance (unadjusted P values) is calculated by comparison of phylogenetically-transformed sum-of-squared Procrustes distances with sum-of-squares distributions generated from residual randomization permutation procedure (RRPP)⁹¹, using 1000 permutations. F-statistic is the ratio between the sum of squares of the regression and the sum of squares of the error. Effect sizes (Z scores) were computed as standard deviations of F-distributions using residual degrees of freedom (re-df).

Back to article page

Table 1 Results of selected phylogenetic Procrustes distance regressions of labyrinth shape ~ independent variables including fossils

Search

Quick links