Metazoans must develop from zygotes to feeding organisms. In doing so, developing offspring consume up to 60% of the energy provided by their parent. The cost of development depends on two rates: metabolic rate, which determines the rate that energy is used; and developmental rate, which determines the length of the developmental period. Both development and metabolism are highly temperature-dependent such that developmental costs should be sensitive to the local thermal environment. Here we develop, parameterise and test Developmental Cost Theory (DCT), a physiologically explicit theory that reveals that ectotherms have narrow thermal windows in which developmental costs are minimised (T_opt). Our DCT-derived estimates of T_opt predict the natural thermal environment of 71 species across 7 phyla remarkably well (R² ~ 0.83). DCT predicts that costs of development are much more sensitive to small changes in temperature than classic measures such as survival. Warming-driven changes to developmental costs are predicted to strongly affect population replenishment, and DCT provides a mechanistic foundation for determining which species are most at risk. DCT predicts tropical aquatic species and most non-nesting terrestrial species are likely to incur the greatest increase in developmental costs from future warming.

The data are mainly collected from a previous synthesis in Pettersen et al (2019) Ecology Letters. 

The data are in the following columns:

B: Species name

C: A temperature dependence of embryonic metabolic rate parameter

D, E, & F: Parameters for describing the temperature dependence of development

G: The calculated temperature that minimises the costs of development

H: Minimum reported environmental temperature

I: Maximum reported environmental temperature

J: Mid-temperature between the minimum and the maximum temperature 

K: Change in the costs of development for a 20% shift in temperature relative to the temperature range

L: Change in survival for a 20% shift in temperature relative to the temperature range

M: Curvature of the development costs relationship evaluated at the optimal temperature