Divergent Selection for Geotactic Response and Evolution of Reproductive Isolation in Sympatric and Allopatric Populations of Houseflies

  title={Divergent Selection for Geotactic Response and Evolution of Reproductive Isolation in Sympatric and Allopatric Populations of Houseflies},
  author={Lawrence E. Hurd and Robert M. Eisenberg},
  journal={The American Naturalist},
  pages={353 - 358}
Experimental populations of houseflies subjected to 95% selective pressure for geotactic preference under conditions of 50% potential gene flow and of allopatry evolved reproductive isolation after only 16 generations. No significant difference was found between sympatric and allopatric populations. Our study does not support the hypothesis that incipient reproductive isolation occurs more rapidly under conditions of sympatry than allopatry. 

Laboratory environments are not conducive for allopatric speciation

It is suggested that allopatric speciation experiments are more likely to yield conclusive results under divergent selection than under drift, and points to the benefits of large populations and many generations.

Adaptation to desiccation resistance fails to generate pre- and postmating isolation in Drosophila melanogaster

The divergence between the desiccation and control populations of cuticular hydrocarbons, key traits that have been implicated in mate choice and sexual isolation in Drosophila, is demonstrated.


The role of geographical separation in generating allopatry has been overemphasized in the past and its role in generating diminished gene flow in combination with strong, discontinuous, and multifarious divergent selection, has been largely unappreciated.

Effective population size may limit the power of laboratory experiments to demonstrate sympatric and parapatric speciation

This study demonstrates that the experimental evidence frequently used as an argument against sympatric and parapatric speciation models is not as strong as previously believed.

Pleiotropic effects of environment-sensitive genes affecting fitness in relation to postmating reproductive isolation

A verbal model is described in which gene flow is no longer seen as being first interrupted by a mere physical barrier and one is concerned with the environment-sensitivity of the mutations implicated in the process, and the other with their presumed pleiotropic action on a behavioural trait.

Investigating the relative influence of genetic drift and natural selection in shaping patterns of population structure in Delphinids (Delphinus delphis; Tursiops spp.)

Large mitogenomic sequences were used to investigate the worldwide phylogeography of several ecotypes/species within the genus Tursiops, with a recent biogeographical calibration point being used to calculate divergence times.

Sympatric speciation: when is it possible?

The present analysis confirms the view that such a selection on sufficiently polymorphic traits for speciation is ecologically realistic and shows that populations with bimodal distributions of some genetically determined quantitative characters can have a considerable life-time.


  • L. NagelD. Schluter
  • Biology, Environmental Science
    Evolution; international journal of organic evolution
  • 1998
Interspecific mate preferences in sympatric sticklebacks appears to be dominated by body size, implicating natural selection in the origin of species.

Non-Allopatric Speciation in Animals

The extent to which the theory and evidence amassed since 1963 warrant a major change in views of animal speciation is reviewed, and the theory of stasipatric speciation and purported cases of sympatrics associated with a shift to a new host are reviewed.


  • D. Dodd
  • Biology
    Evolution; international journal of organic evolution
  • 1989
In an attempt to gain insight into the process of the development of reproductive isolation, eight populations of Drosophila pseudoobscura were studied



Evolution of Reproductive Isolation in Allopatric and Sympatric Populations

Under 5% selective pressure on both sympatric and allopatric populations, both diverged rapidly, with the allop atric populations evolving slightly faster during the 38 generations of the experiment.


One of the most imiportant problems in the study of speciation has been that of the origin of reproductive isolating mechanisms, for it is by the building up of intrinsic barriers which prevent gene

A Population Model of Sympatric Speciation

In this chapter, four genetic mechanisms, "habitat selection, pleiotropic genes, modifying genes, and assortative mating genes" which could result in sympatric speciation are presented.

The Probability of Isolation by Disruptive Selection

Conditions are discussed that may affect the probability of reproductive isolation developing in laboratory disruptive-selection experiments, and only two stocks were suitable for assessing the capacity of natural populations to respond to disruptive selection by producing isolation.

Gene Flow and Population Differentiation

The results of experimental and theoretical models show that it is possible for local differentiation to evolve parapatrically in spite of considerable gene flow if the selection gradients are relatively uniform, andGene flow may be unimportant in the differentiation of populations along environmental gradients.

Effects of Immigration on the Evolution of Populations

The results of these experiments gave further evidence that the degree of isolation necessary for divergent evolution to occur has been overestimated and support the view that sympatric demes under divergent selection are a functional part of the speciation process.

Sexual Isolation Studies in the Species Complex Drosophila Virilis.

The results of SPENCER and PATTERSON, STONE and GRIFFEN suggest the existence of sexual isolation in the virilis complex similar to that found by DOBZHANSKY and KOLLER in D. athabasca, and the success of the mating was not measured directly, but by the offspring obtained, so that many factors besides sexual isolation were involved.

Effects of disruptive selection

It is argued that disruptive selection, when the different forms selected are interdependent, may be expected to produce polymorphic populations, and the evidence already put forward helps to support this argument in so far as it is legitimate to regard polymorphism as but a special extreme form of this general genetic diversity.

Effects of disruptive selection

These experiments involved selection for sternopleural chta number in populations initiated from a wild stock of Drosophila nielanogaster, open to interpretation in terms of Mather's (1943) models, on the supposition that disruptive selection can increase the frequency of coupling linkages of genes hitherto present mostly in repulsion complexes.

Genetics of the Evolutionary Process

  • I. Hiscock
  • Biology
    The Yale Journal of Biology and Medicine
  • 1971
A critical study of evolutionary conservation genetics as applied evolution: from genetic introduction to molecular population genetics holsinger lab evolutionary genetics of california islands peromyscus population and evolutionary genetics mdmtv.