Effects of size and temperature on developmental time

Area of Science:

• Ecology
• Evolutionary Biology
• Physiology

Background:

• Body size and temperature are fundamental factors influencing biological rates and developmental timing.
• Understanding how these factors interact during ontogeny (organism development) is critical, as both size and temperature often change.
• Existing models may not fully capture the complex interplay between size, temperature, and development across diverse taxa.

Purpose of the Study:

• To derive a general biophysical model predicting ontogenetic development time.
• To establish a relationship between body mass, temperature, and the duration of development.
• To test the model's applicability across various animal groups and life stages.

Main Methods:

• Derivation of a general model from principles of allometry (scaling) and biochemical kinetics.
• Testing the model against empirical data for embryonic development in birds and aquatic ectotherms.
• Validating the model with data on post-embryonic development in zooplankton and other animal groups.

Main Results:

• The model accurately predicts embryonic development times across a wide range of egg sizes and incubation temperatures.
• It explains a significant portion (approx. 75%) of variation in post-embryonic zooplankton development.
• Stoichiometry (carbon to phosphorus ratio) partially explains remaining variation in zooplankton development.

Conclusions:

• A general, first-principles model effectively predicts development time as a function of body mass and temperature.
• The model demonstrates broad applicability across diverse organisms and life stages, suggesting a universal biological time.
• This research provides a unified framework for understanding biological time, with implications for ecology and evolutionary biology.