Divergence in proteins, mitochondrial DNA, and reproductive compatibility across the isthmus of Panama.

  title={Divergence in proteins, mitochondrial DNA, and reproductive compatibility across the isthmus of Panama.},
  author={Nancy Knowlton and Lee Weigt and Laura Alexandra Romero Sol{\'o}rzano and David K. Mills and Eldredge Bermingham},
  volume={260 5114},
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… 

New dates and new rates for divergence across the Isthmus of Panama

  • N. KnowltonL. Weigt
  • Biology
    Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1998
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.

Reconstructing the history of intercontinental dispersal in Daphnia lumholtzi by use of genetic markers

The extent of genetic divergence among populations, when coupled with estimates of rates of molecular evolution, suggests that the distribution of Daphnia lumholtzi reflects a series of long‐distance dispersal events over the last 4 million years.

Atypically low rate of cytochrome b evolution in the scleractinian coral genus Acropora

The results indicate that the Acropora cytochrome b gene is evolving at least 10 – 20 times slower than the ‘standard’ vertebrate mtDNA clock and is one of the most slowly evolving animal mitochondrial genes described to date.

Molecular evidence for genetic subdivision of Antarctic krill (Euphausia superba Dana) populations

It is suggested that oceanographic barriers could be sufficiently strong and temporally stable to restrict gene flow between distinct areas and indicate that Antarctic krill is not at mutation–drift equilibrium and that the species possibly has a low effective population size as compared to the census size.


Divergence times in two species pairs were shown to occur much earlier than the Isthmus final closure, but much of the variance in pairwise genetic distances from cytochrome oxidase I (COI) was explained when ancestral polymorphisms were accounted for.

Developing model systems for molecular biogeography: Vicariance and interchange in marine invertebrates

This chapter focuses on studies of littoral marine invertebrates in three well-studied marine model systems, and presents molecular divergence, population genetic, and in some cases, paleontological evidence that sister taxa in neighboring areas likely diverged at different times.


A hypothesis of phylogenetic relationships for all of the currently recognized species of northern hemisphere Nucella is presented, based on an analysis of 718 base pairs of nucleotide sequence from the mitochondrial cytochrome b gene.

Patterns of speciation inferred from mitochondrial DNA in North American Chthamalus (Cirripedia: Balanomorpha: Chthamaloidea).

  • J. Wares
  • Biology
    Molecular phylogenetics and evolution
  • 2001
The data suggest that the little morphological diversification that there has been in Chthamalus occurred early in the history of the genus, and subsequent radiations were probably induced by transient periods of population separation during late Miocene to Recent climatic changes.

A biogeographic framework of octopod species diversification: the role of the Isthmus of Panama

It is suggested that octopod TSSP/TSSC diverged because of these physical and environmental barriers, even before the complete uplift of the IP 3 Ma, proposed by the Late Pliocene model.



Rate variation of protein and mitochondrial DNA evolution as revealed by sea urchins separated by the isthmus of Panama.

  • E. BerminghamH. Lessios
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1993
This work has measured protein divergence by electrophoresis and mitochondrial DNA differentiation by restriction fragment length polymorphism analysis in three pairs of sea urchin species believed to have resulted from the simultaneous fragmentation of ranges of marine species by the emergence of the Isthmus of Panama, about 3 million years ago.

Use of Panamanian sea urchins to test the molecular clock

Evidence is presented from sea urchins separated by the Isthmus of Panama which indicates that even the compromise position of the ‘molecular clock’ hypothesis is not tenable.

Biochemical genetics of the sea anemone Bunodosoma cavernata and the zoogeography of the Gulf of Mexico

Using the genetic distance between Gulf and Atlantic populations of this species as an estimator of time since divergence, it is concluded that the vicariant event was the emergence of Florida in the Pliocene.

Rates of mitochondrial DNA evolution in sharks are slow compared with mammals

Examination of mtDNA sequence variation for 13 species of sharks from two orders that are well represented in the fossil record to test the constancy hypothesis finds differences in mtDNA substitution rates among taxa indicate that it is inappropriate to use a calibration for one group to estimate divergence times or demographic parameters for another group.

Diversity and Extinction of Tropical American Mollusks and Emergence of the Isthmus of Panama

The gradual closure of the Panamanian seaway and the resulting environmental change stimulated an increase in Caribbean molluscan diversity rather than the mass extinction hypothesized previously on

Morphological divergence of Eastern Pacific and Caribbean isopods: effects of a land barrier and the Panama Canal

There was weak evidence that some introductions may have taken place in the last century from the Caribbean to the Pacific; however, introductions have not masked the pattern of divergence that has developed over millions of years.

Adaptation and Phylogeny as Determinants of Egg Size in Echinoderms from the Two Sides of the Isthmus of Panama

  • H. Lessios
  • Biology, Environmental Science
    The American Naturalist
  • 1990
The size of eggs in 22 species of echinoids and 2 species of asteroids from the two sides of the Isthmus of Panama was determined in an effort to assess the rate at which differences between species can accumulate.

Isotopic Paleoceanography of the Caribbean and East Pacific: Role of Panama Uplift in Late Neogene Time

  • L. Keigwin
  • Environmental Science, Geography
  • 1982
Comparisons of carbon isotopic data on benthic foraminifera from Deep Sea Drilling Project sites 502 and 503 suggest that modern circulation patterns in the Caribbean and eastern Pacific developed by 3 million years ago in concert with changing tectonic, climatic, and biogeographic patterns.

Biogeography and Adaptation: Patterns of Marine Life

1. Climate and Limitations of Form Part 1: Patterns of Adaptation along Gradients 2. Shelled Gastropods 3. Bivalves 4. Sessile Organisms Part 2: Interoceanic Patterns of Adaptation 5. Predation and

Closure of the Isthmus of Panama: The near-shore marine record of Costa Rica and western Panama

The final closure of the Isthmus of Panama at ∼3.5 Ma divided the American tropical ocean into two separate and different oceanographic regions. Consequences for the marine biota were profound, but,