Figure 1
From: Experimental evolution of sperm competitiveness in a mammal
The experimental design. Competitive male combinations were generated via a semi-factorial design, creating 32 male combinations. Using all replicate lines the different combinations of monogamous line and polygamous line males were assigned to females with either selection history. To eliminate potential confounding affects due to coevolution within the lines, males and females from the same replicate line did not mate. The entire design was replicated.