scholarly journals Multivariate sexual selection on male tegmina in wild populations of sagebrush crickets,Cyphoderris strepitans(Orthoptera: Haglidae)

2016 ◽  
Vol 30 (2) ◽  
pp. 338-351 ◽  
Author(s):  
G. D. Ower ◽  
J. Hunt ◽  
S. K. Sakaluk
Keyword(s):  
Sexual Selection ◽  
Wild Populations ◽  
Cyphoderris Strepitans

scholarly journals Multivariate sexual selection on male song structure in wild populations of sagebrush crickets,Cyphoderris strepitans(Orthoptera: Haglidae)

2013 ◽  
pp. n/a-n/a
Author(s):  
Geoffrey D. Ower ◽  
Kevin A. Judge ◽  
Sandra Steiger ◽  
Kyle J. Caron ◽  
Rebecca A. Smith ◽  
...  
Keyword(s):  
Sexual Selection ◽  
Wild Populations ◽  
Song Structure ◽  
Male Song ◽  
Cyphoderris Strepitans

scholarly journals Effects of Genotype and Light on Mating Preference in Drosophila Melanogaster

1979 ◽  
Vol 32 (6) ◽  
pp. 607 ◽  
Author(s):  
JG Oakeshott ◽  
DL Hayman
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Genetic Variability ◽  
Mating Success ◽  
Experimental Analysis ◽  
Mating Preference ◽  
Wild Populations ◽  
Visual Defect ◽  
Female Phenotype ◽  
Dark Regime

Patterns of mating have been investigated among yellow-bodied and white-eyed D. melanogaster. The relative mating success of yellow-bodied and white-eyed males was found to depend on both the light/dark regime and the phenotype of the female receiving them. White-eyed males were more likely to succeed in the dark 01' with white-eyed females. The effect of the light/dark regime probably reflected the visual defect in white-eyed males and the effect of the female phenotype was primarily due to strong avoidance of yellow-bodied males by white-eyed females. The overall pattern of mating indicated environment-dependent sexual selection and suggested several models for the experimental analysis of the relations between environmental and genetic variability. Possible implications for wild populations are also discussed.

scholarly journals Cyphoderris Strepitans (Orthoptera: Haglidae): Reproductive Biology and Geographical Distribution

1980 ◽  
Vol 4 ◽  
pp. 53-57
Author(s):  
Darryl Gwynne
Keyword(s):  
Sexual Selection ◽  
Reproductive Success ◽  
National Parks ◽  
Egg Production ◽  
Paternal Care ◽  
Common Species ◽  
Male Reproductive Success ◽  
Male Investment ◽  
Cyphoderris Strepitans ◽  
Variance In Reproductive Success

Cyphoderris strepitans Morris and Gwynne is a common species of nocturnal insect in many sagebrush areas within Grand Tetons and Yellowstone National Parks. It is a primitive orthopteran group, a relict of the ancient family Haglidae. Only five species in three genera are currently known (Morris and Gwynne 1978, Storozhenko 1980). Males produce a calling song by rubbing their forewings together. Females are attracted to male song; during mating the female feeds on the tissues of the male's fleshy underwings. Virgin and non-virgin males can, therefore, be distinguished by examining their underwings. At the end of mating the male transfers a large proteinaceous spermatophore which the female also consumes. The main objective of this study has been to investigate the role and consequences of the male investment in his underwings and spermatophore (see Morris and Gwynne 1979). Female katydids use spermatophore proteins for egg production (Gwynne and Toalson unpublished) so these nutrients can be regarded as an important male investment likely to influence patterns of sexual selection within this group. Trivers (1972) outlined the theory of parental investment and its influence on sexual selection. Females, because they produce fewer larger gametes (eggs) are usually the limiting sex for the males which have a relatively large number of small gametes (sperm). As a result, males are predicted to maximize reproductive success by competing with each other to inseminate as many females as possible. Females, because they are limited by their fewer gametes will not gain by competing for copulations. Instead they should enhance reproductive success by being selective about which males fertilize their eggs. Sexual selection should, therefore, be stronger on males since competition for mates should produce a greater variance in the reproductive success of this sex (i.e., some males obtain few or no mates while others mate frequently). Males can offset the initial disparity of investment in gametes by investing parentally via paternal care of eggs or offspring or, as in many insects, by feeding the female with prey items or glandular products (Thornhill 1976). These sorts of male investments should decrease the variance in reproductive success of these males because the males are more "female like" in their reproductive strategy i.e., competing less because they reduce the number of potential copulations engaged in due to the large nutrient investment in each copulation. In orthopterans such as Cyphoderris where females feed on male-produced nutrients the following predictions emerge: (1) females should select a mate who is likely to provide more of the nutrient; (2) as mentioned above, the variance in male reproductive success should be low; few males should go unmated. Previous work in Grand Teton National Park has indicated that females may prefer Cyphoderris males who can supply more nutrients. Significantly more virgin males are mated than non-virgins (Morris and Gwynne 1979). Virgins are likely to be a better mate choice for females since they have not only more wing material but also would have large reproductive accessory glands capable of producing a full sized spermatophore. The main purpose of this season's work was to investigate the variance in reproductive success of males. An effort was also made to further collect information on the distribution of C. strepitans in and around Grand Teton and Yellowstone national parks. This information is presented first. (* Erratum: pp. 51 and 52 should be 56 and 57)

scholarly journals Mechanisms of Cultural Evolution in the Songs of Wild Bird Populations

2021 ◽  
Vol 12 ◽  
Author(s):  
Heather Williams
Keyword(s):  
Sexual Selection ◽  
Cultural Evolution ◽  
Mean Value ◽  
Directional Selection ◽  
Specific Reference ◽  
Wild Populations ◽  
Rare Form ◽  
Savannah Sparrow ◽  
Savannah Sparrows ◽  
Over Time

Young songbirds draw the source material for their learned songs from parents, peers, and unrelated adults, as well as from innovation. These learned songs are used for intraspecific communication, and have well-documented roles for such functions as territory maintenance and mate attraction. The songs of wild populations differ, forming local “dialects” that may shift over time, suggesting that cultural evolution is at work. Recent work has focused on the mechanisms responsible for the cultural evolution of bird songs within a population, including drift, learning biases (such as conformity and rare-form copying), and selection (including sexual selection). In many songs or song repertoires, variability is partitioned, with some songs or song segments being stable and consistent, while others vary within the population and across time, and still others undergo population-wide transitions over time. This review explores the different mechanisms that shape the cultural evolution of songs in wild populations, with specific reference to a long-term investigation of a single population of philopatric Savannah sparrows. Males learn a single four-segment song during their 1st year and sing the same song thereafter. Within this song, the buzz segment is a population marker, and may be stable for decades – variant forms occur but eventually disappear. In contrast, the middle segment is highly variable both within the population and over time; changes in relative prevalence of different forms may be due to cultural drift or a rare-form learning bias. Within the introductory segment, a high note cluster was replaced by a click train between 1982 and 2010, following an S-shaped trajectory characteristic of both selective sweeps in population genetics and the replacement of one form by another in human language. In the case of the Savannah sparrows, this replacement may have been due to sexual selection. In subsequent generations, the number of clicks within trains increased, a form of cultural directional selection. In contrast to the narrowing of a trait's range during directional selection in genetic systems, variation in the number of clicks in a train increased as the mean value shifted because improvisation during song learning allowed the range of the trait to expand. Thus, in the single short song of the Savannah sparrow, at least four different mechanisms appear to contribute to three different types of cultural evolutionary outcomes. In the future, it will be import to explore the conditions that favor the application of specific (and perhaps conditional) learning rules, and studies such as the ongoing song seeding experiment in the Kent Island Savannah sparrow population will help in understanding the mechanisms that promote or repress changes in a population's song.

scholarly journals Sexual selection can partly explain low frequencies of Segregation Distorter alleles

2021 ◽  
Vol 288 (1959) ◽  
Author(s):  
Thomas A. Keaney ◽  
Therésa M. Jones ◽  
Luke Holman
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Theoretical Model ◽  
Competitive Ability ◽  
Natural Frequencies ◽  
Mendelian Inheritance ◽  
Wild Populations ◽  
Low Frequencies ◽  
Female Remating ◽  
Segregation Distorter

The Segregation Distorter ( SD ) allele found in Drosophila melanogaster distorts Mendelian inheritance in heterozygous males by causing developmental failure of non- SD spermatids, such that greater than 90% of the surviving sperm carry SD . This within-individual advantage should cause SD to fix, and yet SD is typically rare in wild populations. Here, we explore whether this paradox can be resolved by sexual selection, by testing if males carrying three different variants of SD suffer reduced pre- or post-copulatory reproductive success. We find that males carrying the SD allele are just as successful at securing matings as control males, but that one SD variant ( SD-5 ) reduces sperm competitive ability and increases the likelihood of female remating. We then used these results to inform a theoretical model; we found that sexual selection could limit SD to natural frequencies when sperm competitive ability and female remating rate equalled the values observed for SD-5 . However, sexual selection was unable to explain natural frequencies of the SD allele when the model was parameterized with the values found for two other SD variants, indicating that sexual selection alone is unlikely to explain the rarity of SD .

scholarly journals Male Hemolymph Loss During Nuptial Feeding as a Proximate Mechanisim Underlying the Virgin-Male Mating Advantage in Sagebrush Crickets

2003 ◽  
Vol 27 ◽  
pp. 45-50
Author(s):  
Scott Sakaluk ◽  
Mark Campbell ◽  
Peter Keorpes ◽  
Andrew Clark
Keyword(s):  
Sexual Selection ◽  
Male Mating ◽  
Energy Reserves ◽  
Substantial Portion ◽  
Mating Advantage ◽  
Virgin Male ◽  
Cyphoderris Strepitans ◽  
Two Alternatives ◽  
Signaling Activity ◽  
Spermatophore Production

Male sagebrush crickets, Cyphoderris strepitans, offer an unusual nuptial food gift to females during mating: females chew on the ends of the males' fleshy hind wings and ingest hemolymph seeping from the wounds they inflict. Previous studies have shown that once a male had mated, his probability of obtaining an additional copulation is reduced relative to that of a virgin male seeking to secure his first mating, a pattern known as the virgin­male mating advantage. One hypothesis to account for the virgin-male mating advantage is that non­virgin males, having lost a substantial portion of their energy reserves at mating, may be unable to sustain the costly acoustical signaling activity required for the passive attraction of additional females. If the future mating prospects of non-virgin males are diminished because of sexual fatigue, this could stem either from the resources required to manufacture a new spermatophore or through the energy needed to replenish haemolymph lost through female wing­feeding. To distinguish between these two alternatives, we experimentally depleted virgin males of varying amounts haemolymph (0, 5 and 10 ul) in a way that mimicked hemolymph loss of non-virgin males, without the attendant costs of spermatophore production. After they had been treated, males were released in the field and recaptured over the course of the breeding season to monitor their mating success. Control males mated significantly sooner than did males depleted of 5 or 10 ul of hemolymph. We conclude, therefore, that the depletion of hemolymph that occurs through female wing feeding is sufficient by itself to diminish a non-virgin male's ability to secure another mating, acting as a brake on the operation of sexual selection in this species.

scholarly journals In search of an honest butterfly: sexually selected wing coloration and reproductive traits from wild populations of the cabbage white butterfly

2021 ◽  
Author(s):  
Anne E. Espeset ◽  
Matthew L. Forister
Keyword(s):  
Sexual Selection ◽  
Environmental Change ◽  
Mate Selection ◽  
Nitrogen Availability ◽  
Pieris Rapae ◽  
Clear Understanding ◽  
Wild Populations ◽  
Honest Signals ◽  
Cabbage White Butterfly ◽  
Testes Size

AbstractSexual selection is an important and well-studied topic and is central to many theories on mate selection and individual behavior. Relatively little is known about the impacts that human-induced rapid environmental change are having on secondary sexually selected characteristics. In particular, we lack a clear understanding of the effects of the introduction of once-limiting nutrients to wild populations. Honest signals function as an indicator of mate quality when there are differences in nutrient acquisition and allocation to secondary traits. We used the cabbage white butterfly, Pieris rapae (L.), to investigate differences in color and testes size as an index of reproductive potential. We collected individuals from four sites in California and Nevada to capture variation among areas with high and low cropland and potential nitrogen availability. Differences in mean testes size among sites raise the possibility that individuals from sites surrounded by high agricultural areas have smaller testes than individuals from less agriculturally-developed areas. Coloration variables and testes size were positively associated, consistent with the hypothesis that nitrogen-based coloration in the cabbage white is an honest mating signal. However, variation among sites in that relationship suggests complexities that need further exploration, including the possibility that the signal is not of equal value in all populations. Thus these results advance our understanding of complex relationships among human-induced environmental change and sexual selection in the wild.

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