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Size-class histogram of progeny from a cross between Ecuador (female) and New York (male). Individuals measuring >18,000 pixels were considered normal, while those less than this threshold were classed as abnormally developing. Least squared means for males and females are indicated by vertical arrows (male = 34,139; female mean = 39,375; F = 136.1; d.f. = 1, 150; P < 0.0001).
