Fig. 1

C. inopinata develops more slowly than C. elegans. The y-axis represents the status of having attained a given developmental milestone; 0 = has not reached milestone, 1 = has reached milestone. Here, the actual data representing animals at (or not at) developmental milestones are plotted as clouds of points at these values over time. The curves are logistic models of growth that were fit to these data (see Additional files 5 and 6 for data and Additional file 4 for software to generate these models). a) Hatching; b) L4, young adulthood, and the onset of reproduction. C. elegans (fog-2) was used for the embryogenesis milestone to account for the delay caused by obligate outcrossing in C. inopinata. C. elegans N2 is inviable at 30°C, and C. inopinata milestones were not measured at 15°C due to its low fitness at this temperature. N worms=385, C. elegans hatching 15°C; N=417, C. inopinata hatching 20°C; N=320, C. elegans hatching 20°C; N=383, C. inopinata hatching 25°C; N=319, C. elegans hatching 25°C; N=437, C. inopinata hatching 30°C; N=225, C. elegans L4 15°C; N=186, C. inopinata L4 20°C; N=270, C. elegans L4 20°C; N=209, C. inopinata L4 25°C; N=263, C. elegans L4 25°C; N=232, C. inopinata L4 30°C; N=225, C. elegans young adult 15°C; N=186, C. inopinata young adult 20°C; N=270, C. elegans young adult 20°C; N=209, C. inopinata young adult 25°C; N=263, C. elegans young adult 25°C; N=232, C. inopinata young adult 30°C; N=714, C. elegans reproductive adult 15°C; N=380, C. inopinata reproductive adult 20°C; N=677, C. elegans reproductive adult 20°C; N=784, C. inopinata reproductive adult 25°C; N=960, C. elegans reproductive adult 25°C; N=527, C. inopinata reproductive adult 30°C. GLM LRT chi-square p<0.0001 for every C. elegans and C. inopinata comparison.