Divergence in Proteins, Mitochondrial DNA, and Reproductive Compatibility Across the Isthmus of Panama

• Published in: Science (American Association for the Advancement of Science) Vol. 260; no. 5114; pp. 1629 - 1632
• Main Authors: Knowlton, Nancy, Weight, Lee A., Solórzano, Luis Aníbal, Mills, DeEtta K., Bermingham, Eldredge
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 11.06.1993; American Association for the Advancement of Science
• Subjects: Alleles; Alpheus; Animals; Base Sequence; Biological and medical sciences; Decapoda (Crustacea) - enzymology; Decapoda (Crustacea) - genetics; DNA, Mitochondrial - genetics; Ecological genetics; Environmental aspects; Evolution; Evolutionary genetics; Female; Fundamental and applied biological sciences. Psychology; Gene flow; Genetics of eukaryotes. Biological and molecular evolution; Genotype; Geological Phenomena; Geology; Invertebrata; Isoenzymes - genetics; Isolating mechanisms; Larvae; Male; Marine; Mitochondrial DNA; Molecular Sequence Data; Panama; Phylogeny; Population genetics, reproduction patterns; Reproductive isolating mechanisms; Shallow water; Shrimp; Species; Species (Biology); Taxa; Central America; Panama; America; ISE, Panama; ASW, Panama; Crustacea; Genotype environment interaction; Genetic marker; Arthropoda; Phylogenetic tree; Biological evolution; Phylogeny; Invertebrata; Population genetics; Speciation
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.8503007

It is widely believed that gene flow connected many shallow water populations of the Caribbean and eastern Pacific until the Panama seaway closed 3.0 to 3.5 million years ago. Measurements of biochemical and reproductive divergence for seven closely related, transisthmian pairs of snapping shrimps (Alpheus) indicate, however, that isolation was staggered rather than simultaneous. The four least divergent pairs provide the best estimate for rates of molecular divergence and speciation. Ecological, genetic, and geological data suggest that gene flow was disrupted for the remaining three pairs by environmental change several million years before the land barrier was complete.