Figure 6
From: Evolution of testicular architecture in the Drosophilidae: A role for sperm length
Relationships between sperm length and the number of first spermatocytes ( F ) per cyst: a) the relationship for the 57 species for which we have values of both sperm length and F (see Additional file 1 for the data and references) (linear regression, F 1,55 = 86.4, p < 0.001), and b) the phylogenetically controlled relationship from the comparative analysis for the 40 species listed in Figure 5 (independent contrasts, linear regression forced through the origin, F 1,34 = 30.2, p < 0.001).