Search tips
Search criteria 


Logo of procbThe Royal Society PublishingProceedings BAboutBrowse by SubjectAlertsFree Trial
Proc Biol Sci. 2003 December 22; 270(1533): 2551–2555.
PMCID: PMC1691546

Dollo's law and the re-evolution of shell coiling.


Gastropods have lost the quintessential snail feature, the coiled shell, numerous times in evolution. In many cases these animals have developed a limpet morphology with a cap-shaped shell and a large foot. Limpets thrive in marginal habitats such as hydrothermal vents, the high-energy rocky intertidal areas and fresh water, but they are considered to be evolutionary dead-ends, unable to re-evolve a coiled shell and therefore unable to give rise to the diversity seen among coiled snails. The re-evolution of a coiled shell, or any complex character, is considered unlikely or impossible (Dollo's law) because the loss of the character is followed by the loss of the genetic architecture and developmental mechanisms that underlie that character. Here, we quantify the level of coiling in calyptraeids, a family of mostly uncoiled limpets, and show that coiled shells have re-evolved at least once within this family. These results are the first demonstration, to our knowledge, of the re-evolution of coiling in a gastropod, and show that the developmental features underlying coiling have not been lost during 20-100 Myr of uncoiled evolutionary history. This is the first example of the re-evolution of a complex character via a change in developmental timing (heterochrony) rather than a change in location of gene expression (heterotopy).

Full Text

The Full Text of this article is available as a PDF (279K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Collin Rachel. Phylogenetic relationships among calyptraeid gastropods and their implications for the biogeography of marine speciation. Syst Biol. 2003 Oct;52(5):618–640. [PubMed]
  • Gould SJ. Dollo on Dollo's law: irreversibility and the status of evolutionary laws. J Hist Biol. 1970 Fall;3:189–212. [PubMed]
  • Raup DM. THE GEOMETRY OF COILING IN GASTROPODS. Proc Natl Acad Sci U S A. 1961 Apr;47(4):602–609. [PubMed]
  • Whiting Michael F, Bradler Sven, Maxwell Taylor. Loss and recovery of wings in stick insects. Nature. 2003 Jan 16;421(6920):264–267. [PubMed]

Articles from Proceedings of the Royal Society B: Biological Sciences are provided here courtesy of The Royal Society