Evolution and plasticity: Divergence of song discrimination is faster in birds with innate song than in song learners in Neotropical passerine birds

• DOI: 10.1111/evo.13311
• Publication Date: 2017-07-19T12:52:45Z
• Authors: Benjamin G. Freeman; Graham A. Montgomery; Dolph Schluter
• Keywords: Divergence (linguistics)

Plasticity is often thought to accelerate trait evolution and speciation. For example, plasticity in birdsong may partially explain why clades of song learners are more diverse than related with innate song. This "song learning" hypothesis predicts that (1) differences traits evolve faster learners, (2) behavioral discrimination against allopatric (a proxy for premating reproductive isolation) evolves learners. We tested these predictions by analyzing acoustic conducting playback experiments Central American sister pairs learning oscines (N = 42) nonlearning suboscines 27). found nonlearners evolved mean slightly did leaners, the evolutionary rate was 4.3 times These unexpected results be a consequence significantly greater variability (by 54–79%) requires song-learning absolute before achieving same level as suboscines. points "a downside species discrimination, represents an important example reducing diversification increasing variability.