Evol Ecol Res 10: 621-627 (2008)     Full PDF if your library subscribes.

Selection on space use in a polymorphic lizard

Mats Olsson,1* Erik Wapstra,2 Mo Healey,1 Tonia Schwartz1 and Tobias Uller1,3

1School of Biological Sciences, University of Wollongong, Wollongong, NSW 2522, Australia, 2School of Zoology, The University of Tasmania, Hobart, Tasmania 7001, Australia and 3Edward Grey Institute, School of Zoology, University of Oxford, Oxford OX1 3PS, UK

Author to whom all correspondence should be addressed.
e-mail: molsson@uow.edu.au


Background: Polymorphism within the same species, population, and sex is an interesting problem for the evolutionary biologist, since differences in fitness between the morphs have to cancel out over evolutionary time, otherwise morphs of lower fitness would become extinct. One way this may be achieved is through the adoption of different morph-specific reproductive strategies, allowing morphs to become conditional specialists in space (co-existing) or in time (and cycle in frequency). In either case, we expect selection to be disruptive on data pooled across morphs.

Question: In the annual Australian painted dragon lizard (Ctenophorus pictus; less than 10% survive to a second year), red males dominate yellow males in staged contests, and yellow males (sneakers) are superior in sperm competition trials. Here, we ask whether there is ongoing disruptive selection for red males to defend well-defined, smaller territories (dominants) and for yellow males to have larger, more loosely defined territories (sneakers).

Methods: We monitored free-ranging lizards in a natural population, assigned paternity using microsatellites, and calculated selection coefficients to assess ongoing sexual directional and quadratic selection on territory size.

Results and conclusions: Despite the different reproductive strategies, selection on space use in a natural population was not disruptive in either of the two years studied. Instead, there was no difference in territory size between morphs, and in one year there was ongoing directional (positive) and quadratic (stabilizing) selection on territory size applying across both morphs. Thus, divergence of male reproductive strategies in C. pictus does not seem to be related to differences in space use.

Keywords: lizard, polymorphism, selection in the wild.

IF you are connected using the IP of a subscribing institution (library, laboratory, etc.)
or through its VPN.


        © 2008 Mats Olsson. All EER articles are copyrighted by their authors. All authors endorse, permit and license Evolutionary Ecology Ltd. to grant its subscribing institutions/libraries the copying privileges specified below without additional consideration or payment to them or to Evolutionary Ecology, Ltd. These endorsements, in writing, are on file in the office of Evolutionary Ecology, Ltd. Consult authors for permission to use any portion of their work in derivative works, compilations or to distribute their work in any commercial manner.

       Subscribing institutions/libraries may grant individuals the privilege of making a single copy of an EER article for non-commercial educational or non-commercial research purposes. Subscribing institutions/libraries may also use articles for non-commercial educational purposes by making any number of copies for course packs or course reserve collections. Subscribing institutions/libraries may also loan single copies of articles to non-commercial libraries for educational purposes.

       All copies of abstracts and articles must preserve their copyright notice without modification.