scholarly journals The effects of heterospecific mating frequency on the strength of cryptic reproductive barriers

2019 ◽  
Vol 32 (9) ◽  
pp. 900-912
Author(s):  
Erica L. Larson ◽  
Margaret M. Brassil ◽  
Jonathan Maslan ◽  
Danielle Juárez ◽  
Flordeliza Lilagan ◽  
...  
Genetics ◽  
1999 ◽  
Vol 152 (2) ◽  
pp. 713-727 ◽  
Author(s):  
Loren H Rieseberg ◽  
Jeannette Whitton ◽  
Keith Gardner

Abstract Genetic analyses of reproductive barriers represent one of the few methods by which theories of speciation can be tested. However, genetic study is often restricted to model organisms that have short generation times and are easily propagated in the laboratory. Replicate hybrid zones with a diversity of recombinant genotypes of varying age offer increased resolution for genetic mapping experiments and expand the pool of organisms amenable to genetic study. Using 88 markers distributed across 17 chromosomes, we analyze the introgression of chromosomal segments of Helianthus petiolaris into H. annuus in three natural hybrid zones. Introgression was significantly reduced relative to neutral expectations for 26 chromosomal segments, suggesting that each segment contains one or more factors that contribute to isolation. Pollen sterility is significantly associated with 16 of these 26 segments, providing a straightforward explanation of why this subset of blocks is disadvantageous in hybrids. In addition, comparison of rates of introgression across colinear vs. rearranged chromosomes indicates that close to 50% of the barrier to introgression is due to chromosomal rearrangements. These results demonstrate the utility of hybrid zones for identifying factors contributing to isolation and verify the prediction of increased resolution relative to controlled crosses.


2017 ◽  
Vol 42 (3) ◽  
pp. 503-508
Author(s):  
MMH Khan

Experiments were conducted to observe mating and oviposition behabiour as well as biology of hog-plum beetle. Results revealed that the average mating frequency, mating duration and mating interval were 11.2, 30.5 hours and 60.3 hours, respectively. The highest number of eggs per clusters was on leaf rachis followed by young stem. The mean number of eggs per cluster was 15.70 while the length and breadth of an egg was 1.95 mm and 0.60 mm, respectively. The mean duration of 1st, 2nd, 3rd and 4th instar larvae were 3.80, 3.40, 3.70 and 3.00 days, respectively. The mean pupal period was 22.74 days. The female beetle lived longer (48.30 days) than the male (45.10 days). The size of female beetle was larger (15.30 mm) than male (11.96 mm). The mean length of antennae was 7.42 mm. The length of fore, mid and hind legs were 9.20, 9.50 and 11.70 mm, respectively. Hind wings were larger (16.10 mm length and 7.85 mm breadth) than fore wings (12.38 mm length and 5.30 mm breadth).Bangladesh J. Agril. Res. 42(3): 503-508, September 2017


Apidologie ◽  
2003 ◽  
Vol 34 (1) ◽  
pp. 85-86 ◽  
Author(s):  
Wandee Wattanachaiyingcharoen ◽  
Benjamin P. Oldroyd ◽  
Siriwat Wongsiri ◽  
Kellie Palmer ◽  
J�rgen Paar

2017 ◽  
Vol 4 (11) ◽  
pp. 170860 ◽  
Author(s):  
Kensuke Nakata

Some male spiders exhibit female genital mutilation behaviour (FGM) by removing the female genital appendage (scape) to control the mating frequency of females. Female spiders have two, i.e. right and left, genital openings connected with separate spermathecae into which males transfer sperm successively using one pedipalp (secondary genitalia) at a time. Thus, males must complete at least two palpal insertions to fill both spermathecae, before FGM. The present study examined whether (i) scape removal is only associated with the second palpal insertion (one-action hypothesis) or (ii) two contralateral palpal insertions facilitate FGM, with each insertion cutting the basal part of the scape halfway (two-actions hypothesis). Experiments in which females were replaced after a male had made the first insertion did not support the one-action hypothesis, because scapes remained intact after the newly introduced virgin females received their first palpal insertion, which was the second insertion by the males. In comparison, mating experiments using two half-eunuchs (i.e. one of the palps of each male had been manually removed, forcing them to fill female spermatheca on one side only) supported the two-actions hypothesis. FGM was more frequent in females that received two contralateral palpal insertions than in females that received ipsilateral insertions.


2006 ◽  
Vol 361 (1466) ◽  
pp. 363-374 ◽  
Author(s):  
Tristan A.F Long ◽  
Robert Montgomerie ◽  
Adam K Chippindale

Six sister populations of Drosophila melanogaster kept under identical environmental conditions for greater than 600 generations were reciprocally crossed to investigate the incidence of population divergence in allopatry. Population crosses directly influenced fitness, mating frequency, and sperm competition patterns. Changes in both female remating rate and the outcome of male sperm competition (P 1 , P 2 ) in response to foreign males were consistent with intersexual coevolution. Moreover, seven of the 30 crosses between foreign mates resulted in significant reductions in female fitness, whereas two resulted in significant increases, compared to local matings. This tendency for foreign males to reduce female fitness may be interpreted as evidence for either sexually antagonistic coevolution or the disruption of mutualistic interactions. However, instances in which female fitness improved via cohabitation with foreign males may better reveal sexual conflict, signalling release from the cost of interacting with locally adapted males. By this metric, female reproduction in D. melanogaster is strongly constrained by local adaptation by males, a situation that would promote antagonistic coevolution between the sexes. We conclude that sexual selection can promote population differentiation in allopatry and that sexual conflict is likely to have played a role in population differentiation in this study system.


2006 ◽  
Vol 274 (1607) ◽  
pp. 247-252 ◽  
Author(s):  
Paul E Eady ◽  
Leticia Hamilton ◽  
Ruth E Lyons

Antagonistic sexual coevolution stems from the notion that male and female interests over reproduction are in conflict. Such conflicts appear to be particularly obvious when male genital armature inflicts damage to the female reproductive tract resulting in reduced female longevity. However, studies of mating frequency, genital damage and female longevity are difficult to interpret because females not only sustain more genital damage, but also receive more seminal fluid when they engage in multiple copulations. Here, we attempt to disentangle the effects of genital damage and seminal fluid transfer on female longevity in the beetle Callosobruchus maculatus (Coleoptera: Bruchidae). Males copulating for the sixth time in succession inflicted greater levels of genital damage, but transferred smaller ejaculates in comparison with virgin males. The number of copulations performed by males was negatively related to female fecundity and positively related to female longevity, suggesting a trade-off between fecundity and longevity. However, inclusion of fecundity as a covariate revealed sperm and/or seminal fluid transfer to have a negative impact on female longevity above that caused by the fecundity–longevity trade-off. The consequences of multiple copulations on female longevity were examined. Females that mated twice laid more eggs and died sooner than those that mated once. However, incorporation of fecundity as a covariate into our statistical model removed the effect of female mating frequency on female longevity, indicating that double-mated females suffer greater mortality owing to the trade-off between fecundity and longevity. Males of this species are known to transfer very large ejaculates (up to 8% of their body weight), which may represent a significant nutritional benefit to females. However, the receipt of large ejaculates appears to carry costs. Thus, the interpretation of multiple mating experiments on female longevity and associated functional explanations of polyandry in this species are likely to be complex.


Sign in / Sign up

Export Citation Format

Share Document