Selection on space use in a polymorphic lizard
Olsson, M and Wapstra, E and Healey, M and Schwartz, T and Uller, T (2008) Selection on space use in a polymorphic lizard. Evolutionary Ecology Research, 10 . pp. 621-627. ISSN 1522-0613
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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
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|
|Deposited By:||Ms F Walsh|
|Deposited On:||05 Jan 2009 14:26|
|Last Modified:||05 Jan 2009 14:26|
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