A1 Journal article (refereed)
Weak warning signals can persist in the absence of gene flow (2019)

Lawrence, J. P., Rojas, B., Fouquet, A., Mappes, J., Blanchette, A., Saporito, R. A., Bosque, R. J., Courtois, E. A., & Noonan, B. P. (2019). Weak warning signals can persist in the absence of gene flow. Proceedings of the National Academy of Sciences of the United States of America, 116(38), 19037-19045. https://doi.org/10.1073/pnas.1901872116

JYU authors or editors

Publication details

All authors or editors: Lawrence, J. P.; Rojas, Bibiana; Fouquet, Antoine; Mappes, Johanna; Blanchette, Annelise; Saporito, Ralph A.; Bosque, Renan Janke; Courtois, Elodie A.; Noonan, Brice P.

Journal or series: Proceedings of the National Academy of Sciences of the United States of America

ISSN: 0027-8424

eISSN: 1091-6490

Publication year: 2019

Volume: 116

Issue number: 38

Pages range: 19037-19045

Publisher: National Academy of Sciences

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1073/pnas.1901872116

Research data link: https://doi.org/10.17011/jyx/dataset/65263

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/65579


Aposematic organisms couple conspicuous warning signals with a secondary defense to deter predators from attacking. Novel signals of aposematic prey are expected to be selected against due to positive frequency-dependent selection. How, then, can novel phenotypes persist after they arise, and why do so many aposematic species exhibit intrapopulation signal variability? Using a polytypic poison frog (Dendrobates tinctorius), we explored the forces of selection on variable aposematic signals using 2 phenotypically distinct (white, yellow) populations. Contrary to expectations, local phenotype was not always better protected compared to novel phenotypes in either population; in the white population, the novel phenotype evoked greater avoidance in natural predators. Despite having a lower quantity of alkaloids, the skin extracts from yellow frogs provoked higher aversive reactions by birds than white frogs in the laboratory, although both populations differed from controls. Similarly, predators learned to avoid the yellow signal faster than the white signal, and generalized their learned avoidance of yellow but not white. We propose that signals that are easily learned and broadly generalized can protect rare, novel signals, and weak warning signals (i.e., signals with poor efficacy and/or poor defense) can persist when gene flow among populations, as in this case, is limited. This provides a mechanism for the persistence of intrapopulation aposematic variation, a likely precursor to polytypism and driver of speciation.

Keywords: warning coloration; natural selection; defence mechanisms (biological phenomena)

Free keywords: aposematism; frequency-dependent selection; polymorphism; unpalatability; secondary defenses

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Related projects

Ministry reporting: Yes

Reporting Year: 2019

JUFO rating: 3

Last updated on 2021-17-09 at 16:07