Nature & Animals Quote by Peter R. Grant

Grant is quietly picking a fight with the romantic version of evolution that treats “speciation” as a mysterious leap. His sentence is a directive: stop hunting for some special gene-for-new-species magic and look, instead, at what selection can actually see and punish or reward - adult traits. It’s a scientist’s way of demystifying the origin of bird species by anchoring it in the ordinary machinery of survival and mating, where beaks, bodies, songs, plumage, and timing become the currency of divergence.

The phrasing “to be sought” matters. It’s not just descriptive; it’s programmatic, telling the field where to point its microscopes and statistical models. Grant is also narrowing the causal chain: genes matter insofar as they reliably build adult phenotypes that selection can filter. That’s a pushback against explanations that over-credit early developmental quirks or purely neutral genetic drift as primary drivers, at least for the traits most implicated in reproductive isolation.

The subtext is the double engine of “natural and sexual selection.” Natural selection gets you ecological fit; sexual selection gets you preference, display, and the brutal arbitrariness of attraction. In birds, that second force isn’t decorative - it can harden differences quickly, because mate choice is a gatekeeper for gene flow. In the Grants’ Galapagos world, where beak shape tracks food and song tracks mates, “inheritance of adult traits” becomes the bridge between microevolution you can measure and macroevolution you want to explain.