Nature Publishing Group, publisher of Nature, and other science journals and reference works
Nature
my account e-alerts subscribe register
   
Sunday 23 July 2017
Journal Home
Current Issue
AOP
Archive
Download PDF
References
Export citation
Export references
Send to a friend
More articles like this

Letters to Nature
Nature 351, 649 - 652 (20 June 1991); doi:10.1038/351649a0

Is the guinea-pig a rodent?

Dan Graur*, Winston A. Hide & Wen-Hsiung Li§

*Department of Zoology, George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv 69978, Israel
Center for Demographic and Population Genetics, University of Texas, PO Box 20334, Houston, Texas 77225, USA
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030, USA
§To whom correspondence should be addressed.

THE guinea-pig (Caviaporcellus), traditionally classified as a New World hystricomorph rodent, often shows anomalous morphological and molecular features in comparison with other eutherian mammals1–14. For example, its insulin differs from that of other mammals in anabolic and growth-promoting activities and in its capability to form hexamers5,6. Indeed, the literature about the molecular evolution of guinea-pigs abounds in references to 'convergent evolution', 'extremely rapid rates of substitution', and 'unique evolutionary mechanisms'. These claims are based on the assumption that the guinea-pig is a rodent. Our phylogenetic analyses of amino-acid sequence data, however, imply that the guinea-pig diverged before the separation of the primates and the artiodactyls from the myomorph rodents (rats and mice). If true, then the myomorphs and the caviomorphs do not constitute a natural clade, and the Caviomorpha (or the Histricomorpha) should be elevated in taxonomical rank and regarded as a separate mammalian order distinct from the Rodentia. If, as suggested by recent data15,16, the myomorphs branched off before the divergence among the carnivores, lagomorphs, artiodactyls and primates, then the new order would represent an early divergence in eutherian radiation.

------------------

References

1. Nowak, R. M. & Paradiso, J. L. Walker's Mammals of the World (Johns Hopkins University Press, Baltimore, 1983).
2. Romer, A. S. Notes and Comments on Vertebrate Paleontology (University of Chicago Press, 1968).
3. Sahni, A. in Evolutionary Relationships among Rodents: A Multidisciplinary Analysis (eds Luckett, W. P. & Hartenberger, J-L.) 133−150 (Plenum, New York, 1985).
4. Wood, A. E. in Evolutionary Relationships among Rodents: A Multidisciplinary Analysis (eds Luckett, W. P. & Hartenberger, J.-L.) 475−509 (Plenum, New York, 1985).
5. Beintema, J. J. & Campagne, R. N. Molec. Biol. Evol. 4, 10−18 (1987). | PubMed | ChemPort |
6. Watt, V. M. J. biol. Chem. 260, 10926−10929 (1985). | PubMed | ChemPort |
7. Manao, G. et al. J. Prot. Chem. 7, 417−426 (1988). | Article | ChemPort |
8. Shinomura, Y., Eng, J., Rattan, S. C. & Yalow, R. S. Comp. Biochem. Physiol. 96B, 239−242 (1990). | ChemPort |
9. Beintema, J. J. & Neuteboom, B. J. molec. Evol. 19, 145−152 (1983). | PubMed | ChemPort |
10. Sarkar, G., Koeberl, D. D. & Sommer, S. S. Genomics 6, 133−143 (1990). | Article | PubMed | ISI | ChemPort |
11. Fan, Z.-W., Eng, J., Shaw, G. & Yalow, R. S. Peptides 9, 429−431 (1988). | Article | PubMed | ChemPort |
12. Smith, A. I. et al. J. Endocr. 115, R5−R8 (1987). | PubMed | ChemPort |
13. Wolfe, P. B. & Cebra, J. J. Molec. Immun. 17, 1493−1505 (1980). | PubMed | ChemPort |
14. Eng, J., Du, B.-H., Raufman, J.-P. & Yalow, R. S. Peptides 7, Suppl. 1, 17−20 (1986). | Article | PubMed | ChemPort |
15. Easteal, S. Genetics 124, 165−173 (1990). | PubMed | ISI | ChemPort |
16. Li, W.-H., Gouy, M., Sharp, P. M., O'Huigin, C. & Yang, Y.-W. Proc. natn. Acad. Sci. U.S.A. 87, 6703−6707 (1990). | ChemPort |
17. Fitch, W. M. Am. Nat. 16, 111−120 (1980).
18. Felsenstein, J. Syst. Zool. 34, 152−161 (1985).
19. Li, W.-H. & Gouy, M. Meth. Enzym. 183, 645−659 (1990). | PubMed | ChemPort |
20. Fitch, W. M. & Beintema, J. J. Molec. Biol. Evol. 7, 438−443 (1990). | PubMed | ChemPort |
21. Sarich, V. M. & Wilson, A. C. Science 158, 1200−1203 (1973).
22. Shoshani, J., Goodman, M., Czelusniak, J. & Braunitzer, G. in Evolutionary Relationships among Rodents: A Multidisciplinary Analysis (eds Luckett, W. P. & Hartenberger, J.-L. ) 191−210 (Plenum, New York, 1985).
23. Yu, J.-H., Eng, J., Rattan, S. & Yalow, R. S. Peptides 10, 1195−1197 (1989). | Article | PubMed | ChemPort |
24. Li, W.-H., Wu, C.-I. & Luo, C.-C. Molec. Biol. Evol. 2, 150−174 (1985). | PubMed | ISI | ChemPort |
25. Felsenstein, J. Syst. Zool. 27, 401−410 (1978). | ISI |



© 1991 Nature Publishing Group
Privacy Policy