Correlated evolution of morphology and vocal signal structure in Darwin's finches

Abstract

Speciation in many animal taxa is catalysed by the evolutionary diversification of mating signals1. According to classical theories of speciation, mating signals diversify, in part, as an incidental byproduct of adaptation by natural selection to divergent ecologies2,3, although empirical evidence in support of this hypothesis has been limited4,5,6. Here I show, in Darwin's finches of the Galápagos Islands, that diversification of beak morphology and body size has shaped patterns of vocal signal evolution, such that birds with large beaks and body sizes have evolved songs with comparatively low rates of syllable repetition and narrow frequency bandwidths. The converse is true for small birds. Patterns of correlated evolution among morphology and song are consistent with the hypothesis that beak morphology constrains vocal evolution, with different beak morphologies differentially limiting a bird's ability to modulate vocal tract configurations during song production. These data illustrate how morphological adaptation may drive signal evolution and reproductive isolation, and furthermore identify a possible cause for rapid speciation in Darwin's finches.

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.

from$8.99

All prices are NET prices.

Figure 1: Beak morphology (sketches reprinted15) and representative sound spectrograms of songs from eight Darwin's finch species on Santa Cruz Island (from top to bottom: G. magnirostris, G. fortis, G. fuliginosa, G. scandens, C. parvulus, C. psittacula, C. pallida , C. olivacea).
Figure 2: Acoustic analyses.
Figure 3: Vocal deviation as a function of beak depth in G. fortis.
Figure 4: Interspecific analyses.

References

  1. 1

    West-Eberhard, M. J. Sexual selection, social competition, and speciation. Quart. Rev. Biol. 58, 155–183 ( 1983).

    Article  Google Scholar 

  2. 2

    Dobzhansky, T. Genetics and the Origin of Species 3rd edn (Columbia Univ. Press, New York, 1951).

    Google Scholar 

  3. 3

    Mayr, E. Animal Species and Evolution (Harvard Univ. Press, Cambridge, MA, 1963).

    Google Scholar 

  4. 4

    Rice, W. R. & Hostert, E. E. Laboratory experiments on speciation: what have we learned in 40 years? Evolution 47, 1637–1653 (1993).

    Article  Google Scholar 

  5. 5

    Schluter, D. & Nagel, L. Parallel speciation by natural selection. Am. Nat. 146, 292–301 (1995).

    Article  Google Scholar 

  6. 6

    Rundle, H. D., Nagel, L., Boughman, J. W. & Schluter, D. Natural selection and parallel speciation in sympatric sticklebacks. Science 287, 306–308 ( 2000).

    ADS  CAS  Article  Google Scholar 

  7. 7

    Nowicki, S. Vocal tract resonances in oscine bird sound production: evidence from birdsongs in a helium atmosphere. Nature 325, 53– 55 (1987).

    ADS  CAS  Article  Google Scholar 

  8. 8

    Fletcher, N. H. & Tarnopolsky, A. Acoustics of the avian vocal tract. J. Acoust. Soc. Am. 105, 35–49 (1999).

    ADS  Article  Google Scholar 

  9. 9

    Westneat, M. W., Long, J. H. Jr., Hoese, W. & Nowicki, S. Kinematics of birdsong: functional correlation of cranial movements and acoustic features in sparrows. J. Exp. Biol. 182, 147–171 (1993).

    CAS  PubMed  Google Scholar 

  10. 10

    Podos, J., Sherer, J., Peters, S. & Nowicki, S. Ontogeny of vocal tract movements during song production in the song sparrow. Anim. Behav. 50, 1287–1296 ( 1995).

    Article  Google Scholar 

  11. 11

    Hoese, W. J., Podos, J., Boetticher, N. C. & Nowicki, S. Vocal tract function in birdsong production: experimental manipulation of beak movements. J. Exp. Biol. 203, 1845– 1855 (2000).

    CAS  PubMed  Google Scholar 

  12. 12

    Nowicki, S., Westneat, M. W. & Hoese, W. Birdsong: motor function and the evolution of communication. Sem. Neurosci. 4, 385– 390 (1992).

    Article  Google Scholar 

  13. 13

    Podos, J. A performance constraint on the evolution of trilled vocalizations in a songbird family (Passeriformes: Emberizidae). Evolution 51, 537–551 (1997).

    Article  Google Scholar 

  14. 14

    Podos, J. Motor constraints on vocal development in a songbird. Anim. Behav. 51, 1061–1070 ( 1996).

    Article  Google Scholar 

  15. 15

    Bowman, R. I. Morphological differentiation and adaptation in the Galápagos finches. Univ. Calif. Publ. Zool. 58, 1– 302 (1961).

    Google Scholar 

  16. 16

    Bowman, R. I. in Patterns of Evolution in Galápagos Organisms (eds Bowman, R. I., Berson, M. & Leviton, A. E.) 237–537 (American Association for the Advancement of Science, Pacific Division, San Francisco, 1983).

    Google Scholar 

  17. 17

    Schluter, D., Price, T. D. & Grant, P. R. Ecological character displacement in Darwin's finches. Science 227, 1056–1059 (1985).

    ADS  CAS  Article  Google Scholar 

  18. 18

    Gibbs, H. L. & Grant, P. R. Oscillating selection in Darwin's finches. Nature 327, 511– 513 (1987).

    ADS  Article  Google Scholar 

  19. 19

    Grant, P. R. Ecology and Evolution of Darwin's Finches 2nd edn (Princeton Univ. Press, Princeton, 1999).

    Google Scholar 

  20. 20

    Felsenstein, J. Phylogenies and the comparative method. Am. Nat. 125 , 1–25 (1985).

    Article  Google Scholar 

  21. 21

    Martins, E. P. COMPARE, version 4.2. Computer Programs for the Statistical Analysis of Comparative Data (Univ. Oregon, Eugene, Oregon, 1999).

    Google Scholar 

  22. 22

    Cutler, B. Anatomical Studies on the Syrinx of Darwin's Finches. Thesis, San Francisco State Univ. (1970).

  23. 23

    Ryan, M. J. & Brenowitz, E. A. The role of body size, phylogeny, and ambient noise in the evolution of bird song. Am. Nat. 126, 87–100 (1985).

    Article  Google Scholar 

  24. 24

    Grant, P. R. & Grant, B. R. Predicting microevolutionary responses to directional selection on heritable variation. Evolution 49, 241–251 (1995).

    Article  Google Scholar 

  25. 25

    Grant, P. R. & Grant, B. R. Cultural inheritance of song and its role in the evolution of Darwin's finches. Evolution 50, 2471–2487 (1996).

    Article  Google Scholar 

  26. 26

    Ratcliffe, L. M. & Grant, P. R. Species recognition in Darwin's finches (Geospiza, Gould. III. Male responses to playback of different song types, dialects and heterospecific songs. Anim. Behav. 33, 290–307 ( 1985).

    Article  Google Scholar 

  27. 27

    Grant, P. R. & Grant, B. R. Speciation and hybridization in island birds. Phil. Trans. R. Soc. Lond. B 351, 765–772 (1996).

    ADS  Article  Google Scholar 

  28. 28

    Mooers, A. Ø., Vamosi, S. M. & Schluter, D. Using phylogenies to test macroevolutionary hypotheses of trait evolution in cranes (Gruinae). Am. Nat. 154 , 249–259 (1999).

    Article  Google Scholar 

  29. 29

    Petren, K., Grant, B. R. & Grant, P. R. A phylogeny of Darwin's finches based on microsatellite DNA length variation. Proc. R. Soc. Lond. Ser. B. 266 , 321–330 (1999).

    CAS  Article  Google Scholar 

  30. 30

    Sato, A. et al. Phylogeny of Darwin's finches as revealed by mtDNA sequences. Proc. Natl Acad. Sci. USA 96, 5101– 5106 (1999).

    ADS  CAS  Article  Google Scholar 

Download references

Acknowledgements

Field work was coordinated through the Charles Darwin Research Station and the Galápagos National Park Service. I thank M. Rossi-Santos, M. Moreano, H. Vargas, H. Snell and M. Hau for assistance in the field; S. Nowicki, L. Baptista, R. Bensted-Smith, R. Bowman, P. & R. Grant, A. Hendry, W. Hoese, S. Hopp, J. Jaenike, J. Lundberg, W. Maddison, L. McDade, C. Nufio, D. Papaj, S. Patek and R. Prum for discussion and feedback; and the National Science Foundation, the Univ. Arizona Foundation, the Univ. Arizona Office of the Vice President for Research and TAME airlines for financial support.

Author information

Affiliations

Authors

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Podos, J. Correlated evolution of morphology and vocal signal structure in Darwin's finches. Nature 409, 185–188 (2001). https://doi.org/10.1038/35051570

Download citation

Further reading

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Sign up for the Nature Briefing newsletter for a daily update on COVID-19 science.
Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing