Abstract
Sister species separated by the Isthmus of Panama have been widely used to estimate rates of molecular evolution. These estimates are based on the assumption that geographic isolation occurred nearly simultaneously for most taxa, when connections between the Caribbean and eastern Pacific closed approximately three million years ago. Here we show that this assumption is invalid for the only genus for which many taxa and multiple genetic markers have been analysed. Patterns of divergence exhibited by allozymes and the mitochondrial COI gene are highly concordant for 15 pairs of snapping shrimp in the genus Alpheus, indicating that they provide a reasonable basis for estimating time since cessation of gene flow. The extent of genetic divergence between pairs of sister species varied over fourfold. Sister species from mangrove environments showed the least divergence, as would be expected if these were among the last habitats to be divided. Using this pair yields a rate of sequence divergence of 1.4% per one million years, with implied times of separation for the 15 pairs of 3 to 18 million years ago. Many past studies may have overestimated rates of molecular evolution because they sampled pairs that were separated well before final closure of the Isthmus.
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Selected References
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- Bermingham E., Lessios H. A. Rate variation of protein and mitochondrial DNA evolution as revealed by sea urchins separated by the isthmus of Panama. Proc Natl Acad Sci U S A. 1993 Apr 1;90(7):2734–2738. doi: 10.1073/pnas.90.7.2734. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Burton R. S., Lee B. N. Nuclear and mitochondrial gene genealogies and allozyme polymorphism across a major phylogeographic break in the copepod Tigriopus californicus. Proc Natl Acad Sci U S A. 1994 May 24;91(11):5197–5201. doi: 10.1073/pnas.91.11.5197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Collins L. S., Budd A. F., Coates A. G. Earliest evolution associated with closure of the Tropical American Seaway. Proc Natl Acad Sci U S A. 1996 Jun 11;93(12):6069–6072. doi: 10.1073/pnas.93.12.6069. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goldman B. D. Famciclovir for genital herpes. JAMA. 1997 Jan 15;277(3):210–211. [PubMed] [Google Scholar]
- Goldman N. Variance to mean ratio, R(t), for poisson processes on phylogenetic trees. Mol Phylogenet Evol. 1994 Sep;3(3):230–239. doi: 10.1006/mpev.1994.1025. [DOI] [PubMed] [Google Scholar]
- Jackson J. B., Jung P., Coates A. G., Collins L. S. Diversity and extinction of tropical american mollusks and emergence of the isthmus of panama. Science. 1993 Jun 11;260(5114):1624–1626. doi: 10.1126/science.260.5114.1624. [DOI] [PubMed] [Google Scholar]
- Joseph L., Moritz C., Hugall A. Molecular support for vicariance as a source of diversity in rainforest. Proc Biol Sci. 1995 May 22;260(1358):177–182. doi: 10.1098/rspb.1995.0077. [DOI] [PubMed] [Google Scholar]
- Knowlton N., Weigt L. A., Solórzano L. A., Mills D. K., Bermingham E. Divergence in proteins, mitochondrial DNA, and reproductive compatibility across the isthmus of Panama. Science. 1993 Jun 11;260(5114):1629–1632. doi: 10.1126/science.8503007. [DOI] [PubMed] [Google Scholar]
- Martin A. P., Naylor G. J., Palumbi S. R. Rates of mitochondrial DNA evolution in sharks are slow compared with mammals. Nature. 1992 May 14;357(6374):153–155. doi: 10.1038/357153a0. [DOI] [PubMed] [Google Scholar]
- McMillan W. O., Palumbi S. R. Concordant evolutionary patterns among Indo-West Pacific butterflyfishes. Proc Biol Sci. 1995 May 22;260(1358):229–236. doi: 10.1098/rspb.1995.0085. [DOI] [PubMed] [Google Scholar]
- Metz E. C., Gómez-Gutiérrez G., Vacquier V. D. Mitochondrial DNA and bindin gene sequence evolution among allopatric species of the sea urchin genus Arbacia. Mol Biol Evol. 1998 Feb;15(2):185–195. doi: 10.1093/oxfordjournals.molbev.a025914. [DOI] [PubMed] [Google Scholar]
- doi: 10.1098/rspb.1998.0310. [DOI] [PMC free article] [Google Scholar]
- Vermeij G. J. When biotas meet: understanding biotic interchange. Science. 1991 Sep 6;253(5024):1099–1104. doi: 10.1126/science.253.5024.1099. [DOI] [PubMed] [Google Scholar]
- Wu C. I., Li W. H. Evidence for higher rates of nucleotide substitution in rodents than in man. Proc Natl Acad Sci U S A. 1985 Mar;82(6):1741–1745. doi: 10.1073/pnas.82.6.1741. [DOI] [PMC free article] [PubMed] [Google Scholar]