Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection Hypothesis
The developmental instability (DI)-sexual selection hypothesis proposes that large size and symmetry in secondary sexual traits are favored by sexual selection because they reveal genetic quality. A critical prediction of this hypothesis is that there should exist negative correlations between trait...
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MDPI AG
2015-06-01
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| Series: | Symmetry |
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| Online Access: | http://www.mdpi.com/2073-8994/7/2/976 |
| _version_ | 1811185235579109376 |
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| author | Michal Polak Kassie J. Hooker Frances Tyler |
| author_facet | Michal Polak Kassie J. Hooker Frances Tyler |
| author_sort | Michal Polak |
| collection | DOAJ |
| description | The developmental instability (DI)-sexual selection hypothesis proposes that large size and symmetry in secondary sexual traits are favored by sexual selection because they reveal genetic quality. A critical prediction of this hypothesis is that there should exist negative correlations between trait fluctuating asymmetry (FA) and size of condition dependent sexual traits; condition dependent traits should reveal an organism’s overall health and vigor, and be influenced by a multitude of genetic loci. Here, we tested for the predicted negative FA-size correlations in the male sex comb of Drosophila bipectinata. Among field-caught males from five widely separated geographic localities, FA-size correlations were consistently positive, despite evidence that sex comb size is condition dependent. After controlling for trait size, FA was significantly negatively correlated with body size within several populations, indicating that developmental instability in the comb may reveal individual genetic quality. We suggest the possibility that condition dependent traits in some cases tap into independent units of the genome (a restricted set of genes), rather than signaling overall genetic properties of the organism. There were pronounced among-population differences in both comb FA and size, and these traits were positively correlated across populations, recapitulating the within-population patterns. We conclude that the results are inconsistent with the DI-sexual selection hypothesis, and discuss potential reasons for positive FA-size co-variation in sexual traits. |
| first_indexed | 2024-04-11T13:26:01Z |
| format | Article |
| id | doaj.art-b982dab53d974e9fa505b45017414e6d |
| institution | Directory Open Access Journal |
| issn | 2073-8994 |
| language | English |
| last_indexed | 2024-04-11T13:26:01Z |
| publishDate | 2015-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Symmetry |
| spelling | doaj.art-b982dab53d974e9fa505b45017414e6d2022-12-22T04:22:04ZengMDPI AGSymmetry2073-89942015-06-017297699310.3390/sym7020976sym7020976Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection HypothesisMichal Polak0Kassie J. Hooker1Frances Tyler2Department of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221-0006, USADepartment of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221-0006, USADepartment of Biological Sciences, University of Cincinnati, Cincinnati, OH 45221-0006, USAThe developmental instability (DI)-sexual selection hypothesis proposes that large size and symmetry in secondary sexual traits are favored by sexual selection because they reveal genetic quality. A critical prediction of this hypothesis is that there should exist negative correlations between trait fluctuating asymmetry (FA) and size of condition dependent sexual traits; condition dependent traits should reveal an organism’s overall health and vigor, and be influenced by a multitude of genetic loci. Here, we tested for the predicted negative FA-size correlations in the male sex comb of Drosophila bipectinata. Among field-caught males from five widely separated geographic localities, FA-size correlations were consistently positive, despite evidence that sex comb size is condition dependent. After controlling for trait size, FA was significantly negatively correlated with body size within several populations, indicating that developmental instability in the comb may reveal individual genetic quality. We suggest the possibility that condition dependent traits in some cases tap into independent units of the genome (a restricted set of genes), rather than signaling overall genetic properties of the organism. There were pronounced among-population differences in both comb FA and size, and these traits were positively correlated across populations, recapitulating the within-population patterns. We conclude that the results are inconsistent with the DI-sexual selection hypothesis, and discuss potential reasons for positive FA-size co-variation in sexual traits.http://www.mdpi.com/2073-8994/7/2/976fluctuating asymmetrydevelopmental instabilitysecondary sexual traitasymmetry-size co-variationsex combsexual selectionDrosophila bipectinata |
| spellingShingle | Michal Polak Kassie J. Hooker Frances Tyler Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection Hypothesis Symmetry fluctuating asymmetry developmental instability secondary sexual trait asymmetry-size co-variation sex comb sexual selection Drosophila bipectinata |
| title | Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection Hypothesis |
| title_full | Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection Hypothesis |
| title_fullStr | Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection Hypothesis |
| title_full_unstemmed | Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection Hypothesis |
| title_short | Consistent Positive Co-Variation between Fluctuating Asymmetry and Sexual Trait Size: A Challenge to the Developmental Instability-Sexual Selection Hypothesis |
| title_sort | consistent positive co variation between fluctuating asymmetry and sexual trait size a challenge to the developmental instability sexual selection hypothesis |
| topic | fluctuating asymmetry developmental instability secondary sexual trait asymmetry-size co-variation sex comb sexual selection Drosophila bipectinata |
| url | http://www.mdpi.com/2073-8994/7/2/976 |
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