2017/06/23 by Mary Caswell Stoddard, Ee Hou Yong, Derya Akkaynak +3 · 6 citations
Environmental Science · Earth and Planetary Sciences · Mathematics · #Avian ecology and behavior #Paleontology and Evolutionary Biology #Morphological variations and asymmetry
paper · doi:10.1126/science.aaj1945
openalex publication_date 2017/06/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Avian egg shape is generally explained as an adaptation to life history, yet we currently lack a global synthesis of how egg-shape differences arise and evolve. Here, we apply morphometric, mechanistic, and macroevolutionary analyses to the egg shapes of 1400 bird species. We characterize egg-shape diversity in terms of two biologically relevant variables, asymmetry and ellipticity, allowing us to quantify the observed morphologies in a two-dimensional morphospace. We then propose a simple mechanical model that explains the observed egg-shape diversity based on geometric and material properties of the egg membrane. Finally, using phylogenetic models, we show that egg shape correlates with flight ability on broad taxonomic scales, suggesting that adaptations for flight may have been critical drivers of egg-shape variation in birds.