Study of the genetic and developmental architecture of mate preferences lags behind the study of sexual ornaments. This is in part because of the challenges involved in describing mate preferences, which are expressed as a function of variation in ornaments. We used the function-valued approach to test for genetic and environmental components of variation in female mate preferences in Enchenopa treehoppers (Hemiptera: Membracidae). These insects communicate with plant-borne vibrational signals, and offer a case study of speciation involving sexual selection and environmental change. We focused on female preferences for male signal frequency, the most divergent signal trait in Enchenopa. Obtaining complete, individuallevel descriptions of mate preferences in a full-sib, split-family rearing experiment, we document substantial genetic variation in mate preference functions. Focusing on traits describing variation in the shape of the preference functions, we further document considerable broad-sense heritability and evidence of weak genotype 9 environment interaction in most traits. Against the background of recent and rapid divergence in Enchenopa, these results indicate potent mechanisms that maintain variation and sustain the involvement of mate preferences in sexual selection.
Parental care can be partitioned into traits that involve direct engagement with offspring and traits that are expressed as an extended phenotype and influence the developmental environment, such as constructing a nursery. Here, we use experimental evolution to test whether parents can evolve modifications in nursery construction when they are experimentally prevented from supplying care directly to offspring. We exposed replicate experimental populations of burying beetles (Nicrophorus vespilloides) to different regimes of posthatching care by allowing larvae to develop in the presence (Full Care) or absence of parents (No Care). After only 13 generations of experimental evolution, we found an adaptive evolutionary increase in the pace at which parents in the No Care populations converted a dead body into a carrion nest for larvae. Cross-fostering experiments further revealed that No Care larvae performed better on a carrion nest prepared by No Care parents than did Full Care larvae. We conclude that parents construct the nursery environment in relation to their effectiveness at supplying care directly, after offspring are born. When direct care is prevented entirely, they evolve to make compensatory adjustments to the nursery in which their young will develop. The rapid evolutionary change observed in our experiments suggests there is considerable standing genetic variation for parental care traits in natural burying beetle populations—for reasons that remain unclear.
Sudden declines of frequent and effective pollinators are often assumed to reduce pollination success. Yet this assumption has rarely been tested experimentally and may depend upon responses of other pollinators in the community. We temporarily excluded bumble bees in populations of the milkweed Asclepias verticillata, and quantified pollinator visitation rates and pollen receipt in both control and bumble bee exclusion plots. Asclepias pollination success did not decline following bee exclusion due to a nearly three-fold increase in wasp visitation. This highlights the importance of studies that explore the effectiveness and compensatory responses of other pollinator species in the community.
Fisherian selection is a within-population process that promotes signal–preference coevolution and speciation due to signal–preference genetic correlations. The importance of the contribution of Fisherian selection to speciation depends in part on the answer to two outstanding questions: What explains differences in the strength of signal–preference genetic correlations? And, how does the magnitude of within-species signal–preference covariation compare to species differences in signals and preferences? To address these questions, we tested for signal–preference genetic correlations in two members of the Enchenopa binotata complex, a clade of plant-feeding insects wherein speciation involves the colonization of novel host plants and signal–preference divergence. We used a full-sibling, split-family rearing experiment to estimate genetic correlations and to analyze the underlying patterns of variation in signals and preferences. Genetic correlations were weak or zero, but exploration of the underlying patterns of variation in signals and preferences revealed some full-sib families that varied by as much as 50% of the distance between similar species in the E. binotata complex. This result was stronger in the species that showed greater amounts of genetic variation in signals and preferences. We argue that some forms of weak signal–preference genetic correlation may have important evolutionary consequences.
Adaptive plasticity often offsets the negative effects of rapid environmental change. However, anthropogenic stressors like noise and artificial light at night (ALAN) are often unlike those environments experienced ancestrally, making the resulting responses of individuals potentially maladaptive or less predictable. Further uncertainty stems from few studies exploring how the two anthropogenic stressors may interact to influence individual responses. Here we reared female Gryllus veletis field crickets in traffic noise, ALAN, both, or neither to assess how each environment impacted their development, mating behaviors, and reproductive output. We first found that anthropogenic stressors influenced female development in three ways: those reared in ALAN took longer to reach adulthood, females reared in traffic noise were smaller as adults, and females reared in traffic noise lived longer than those reared in both anthropogenic stressors. We then documented pronounced effects on their behaviors and fitness. Females reared in noise in any capacity were more responsive to advertising males and mated with them faster, and females reared in any anthropogenic stressor retained spermatophores longer. Perhaps more significantly, any anthropogenic stressor reduced the lifetime fitness of females through reduced oviposition, hatching success, both, or reduced offspring size at hatching. However, we did not find decreased fitness of females reared with both anthropogenic stressors relative to those reared with just one. Our results highlight how novel anthropogenic stressors may impact populations, but whether individuals can adapt may depend on an interplay between development, mating behaviors, and reproductive output.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.