Table 2

Principal component analysis on phylogenetically independent contrasts of love-dart and reproductive morphology data.

Component loadings


Data

PC1

PC2

PC3

PC4


Love-dart

Number of darts

0.807*

-0.212

-0.262

0.050

Number of blades

0.492†

0.544

0.303

0.318

Length of blades

0.664*

0.381

0.517

0.158

Curvature

0.534*

0.169

0.127

0.668

Functional stylophore(s)

Number

0.781*

-0.204

-0.379

-0.219

Relative size

0.411†

0.498†

-0.447

0.393

Placement on vaginal duct

0.536*

0.053

-0.578

-0.286

Vestigial stylophore(s)

Number

0.527†

-0.775

0.125

0.013

Relative size

0.361†

-0.655

0.258

0.180

Placement on vaginal duct

0.527†

-0.753

0.165

0.106

Glands

Number

0.709*

-0.339

-0.050

-0.225

Relative size

0.472

0.592

-0.275

-0.089

Type of branching

0.275

0.360

-0.277

0.189

Placement

0.871*

-0.133

-0.050

0.258

Diverticulum of spermatophore receiving organ

Length relative to bursa tract

0.457

0.359

0.216

-0.470

Placement

0.554*

0.308

0.431

-0.342

Relative size

0.184*

0.454

0.303

-0.167

Flagellum

Relative length

0.614*

0.141

0.138

-0.429


The independent contrasts are based on the trees reconstructed with BI without consideration of five cases of phylogenetic uncertainty. The table shows the loadings for each variable in the different principal components (PC1 to PC4). Collectively the principal components explain over 70% of the total variance in the data set (respectively, 32.5%, 19.3%, 9.6%, and 9.0 %). Tests of significance of variable loadings represent frequency of loadings different in sign to the ones observed, among 1000 bootstrap replicate analyses corrected for axis reversals (*, P < 0.05; †, P < 0.15).

Koene and Schulenburg BMC Evolutionary Biology 2005 5:25   doi:10.1186/1471-2148-5-25

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