Do directional selection on directional asymmetry affect testes size and secondary sexual characters in birds?
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Directional selection on directional asymmetry does affect testes size and secondary sexual characters in birds. The degree of testes size asymmetry is positively associated with relative livers and body fat mass, supporting the packaging hypothesis . Sperm competition also influences directional asymmetry, with species experiencing higher levels of sperm competition having a relatively larger right testis and more sperm in the right seminal glomerus . However, there is no significant relationship between testes asymmetry and male condition or secondary sexual traits . These findings suggest that natural and sexual selection play a role in driving testes size asymmetry, but the relationship with male quality and secondary sexual traits is not well supported.
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15 Citations | The provided paper does not directly address the question of whether directional selection on directional asymmetry affects testes size and secondary sexual characters in birds. |
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