Phenotypic and genetic variation in emergence and development time of a trimorphic damselfly

Abstract

Although colour polymorphisms in adult organisms of many taxa are often adaptive in the context of sexual selection or predation, genetic correlations between colour and other phenotypic traits expressed early in ontogeny could also play an important role in polymorphic systems. We studied phenotypic and genetic variation in development time among female colour morphs in the polymorphic damselfly Ischnura elegans in the field and by raising larvae in a common laboratory environment. In the field, the three different female morphs emerged at different times. Among laboratory-raised families, we found evidence of a significant correlation between maternal morph and larval development time in both sexes. This suggests that the phenotypic correlation between morph and emergence time in the field has a parallel in a genetic correlation between maternal colour and offspring development time. Maternal colour morph frequencies could thus potentially change as correlated responses to selection on larval emergence dates. The similar genetic correlation in male offspring suggests that sex-limitation in this system is incomplete, which may lead to an ontogenetic sexual conflict between selection for early male emergence (protandry) and emergence times associated with maternal morph.

Correlational Selection on Lay Date and Life-History Traits: Experimental Manipulations of Territory and Nest Site Quality

“…The fitness surfaces in Figures 6 and 7 demonstrate that egg size and laying dates are under strong correlational selection in this system, and the experimental manipulation of territory quality ties selection to the availability of good-quality territory. Correlational selection acts on the genetic architecture of morphs (Forsman and Appelqvist 1998;Abbott and Svensson 2005), favoring successful combinations of genes for egg mass and laying date in the two alternative morphs of females cor-relation selection on a large number of female traits is reviewed in Sinervo and Svensson 2002). Elsewhere (Sinervo and Calsbeek, unpubl.…”

“…Life-history tradeoffs in female side-blotched lizards lead to disruptive selection that favors alternative combinations of traits that determine life history, behavior, and physiology Sinervo and Zamudio 2001). Disruptive se-lection favoring nonrandom combinations of traits is referred to as correlational selection (Brodie et al 1995;McGlothlin et al 2005) and may be responsible for the origin or maintenance of alternative strategies (Forsman and Appelqvist 1998;Sinervo and Svensson 2002;Abbott and Svensson 2005). Previous work in this system has revealed a variety of trait combinations that are under correlational selection (e.g., clutch size, egg size, immunocompetence, and laying date [Svensson et al 2001;Sinervo and Svensson 2002]).…”

Assessing the extent of genome‐wide intralocus sexual conflict via experimentally enforced gender‐limited selection

“…Intralocus sexual conflict has been found in a wide variety of taxa and for many traits including body size (Lindenfors et al, 2002), morphology (Merilä et al, 1997), coloration (Price & Burley, 1994;Forsman, 1995;Forsman & Appelqvist, 1999), development (Abbott & Svensson, 2005) and reproductive output (Hunt et al, 2006). The most compelling genetic evidence for intralocus sexual conflict comes from the Drosophila melanogaster laboratory model system, where a negative genetic correlation between adult lifetime fitness between the sexes has been found Gibson et al, 2002).…”

Intralocus Sexual Conflict Over Immune Defense, Gender Load, and Sex-Specific Signaling in a Natural Lizard Population

“…Phenotypic traits that have been suggested or shown to be affected by intralocus sexual conflict in animals include body size (Badyaev 2002;Calsbeek and Sinervo 2004;Prasad et al 2007), development time (Abbott and Svensson 2005), locomotor activity (Long and Rice 2007), and immune defense (Rolff 2002;Mckean and Nunney 2005;Rolff et al 2005;Calsbeek and Bonneaud 2008). Immune defense in particular is an important fitness-related trait as it enables animals to protect themselves against parasites or infectious diseases (Rolff 2002).…”