Your mother's blue eggs

Abstract

Evolution![Figure][1] Blue cuckoo eggs (topmost on the right) are maternally inherited PHOTO: T. GRIM & M. HAUBER The common cuckoo is able to lay its eggs in the nests of a variety of other bird species due to the fact that different cuckoo races lay different-colored eggs. Most of these eggs are spotted, or “maculated,” in various degrees of brown. One race, however, produces immaculate blue eggs, the origin of which has long been something of a mystery. Fossoy et al. sampled eggs across Europe and Asia and found that cuckoo races with blue eggs are distinguished only by maternally inherited components of the genome. Further, females laying blue eggs belong to a single lineage that originated in Asia roughly 2.4 million years ago, and later spread across the continent. Nat. Commun. 10.1038/ncomms10272 (2016). [1]: pending:yes