High rate of extrapair paternity in a human population demonstrates diversity in human reproductive strategies.
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ABSTRACT:
SUBMITTER: Scelza BA
PROVIDER: S-EPMC7030936 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:BackgroundThe rate of extrapair paternity is a commonly used index for the risk of sperm competition in birds, but paternity data exist for only a few percent of the approximately 10400 extant species. As paternity analyses require extensive field sampling and costly lab work, species coverage in this field will probably not improve much in the foreseeable future. Recent findings from passerine birds, which constitute the largest avian order (?5,900 species), suggest that sperm phenotypes carry a signature of sperm competition. Here we examine how well standardized measures of sperm length variation can predict the rate of extrapair paternity in passerine birds.Methodology/principal findingsWe collected sperm samples from 55 passerine species in Canada and Europe for which extrapair paternity rates were already available from either the same (n = 24) or a different (n = 31) study population. We measured the total length of individual spermatozoa and found that both the coefficient of between-male variation (CV(bm)) and within-male variation (CV(wm)) in sperm length were strong predictors of the rate of extrapair paternity, explaining as much as 65% and 58%, respectively, of the variation in extrapair paternity among species. However, only the CV(bm) predictor was independent of phylogeny, which implies that it can readily be converted into a currency of extrapair paternity without the need for phylogenetic correction.Conclusion/significanceWe propose the CV(bm) index as an alternative measure to extrapair paternity for passerine birds. Given the ease of sperm extraction from male birds in breeding condition, and a modest number of sampled males required for a robust estimate, this new index holds a great potential for mapping the risk of sperm competition across a wide range of passerine birds.
| S-EPMC2956655 | biostudies-literature
Project description:BackgroundVibrio parahaemolyticus is frequently isolated from environmental and seafood samples and associated with gastroenteritis outbreakes in American, European, Asian and African countries. To distinguish between different lineages of V. parahaemolyticus various genotyping techniques have been used, incl. multilocus sequence typing (MLST). Even though some studies have already applied MLST analysis to characterize V. parahaemolyticus strain sets, these studies have been restricted to specific geographical areas (e.g. U.S. coast, Thailand and Peru), have focused exclusively on pandemic or non-pandemic pathogenic isolates or have been based on a limited strain number.ResultsTo generate a global picture of V. parahaemolyticus genotype distribution, a collection of 130 environmental and seafood related V. parahaemolyticus isolates of different geographical origins (Sri Lanka, Ecuador, North Sea and Baltic Sea as well as German retail) was subjected to MLST analysis after modification of gyrB and recA PCRs. The V. parahaemolyticus population was composed of 82 unique Sequence Types (STs), of which 68 (82.9%) were new to the pubMLST database. After translating the in-frame nucleotide sequences into amino acid sequences, less diversity was detectable: a total of 31 different peptide Sequence Types (pSTs) with 19 (61.3%) new pSTs were generated from the analyzed isolates. Most STs did not show a global dissemination, but some were supra-regionally distributed and clusters of STs were dependent on geographical origin. On peptide level no general clustering of strains from specific geographical regions was observed, thereby the most common pSTs were found on all continents (Asia, South America and Europe) and rare pSTs were restricted to distinct countries or even geographical regions. One lineage of pSTs associated only with strains from North and Baltic Sea strains was identified.ConclusionsOur study reveals a high genetic diversity in the analyzed V. parahaemolyticus strain set as well as for geographical strain subsets, with a high proportion of newly discovered alleles and STs. Differences between the subsets were identified. Our data support the postulated population structure of V. parahaemolyticus which follows the 'epidemic' model of clonal expansion. Application of peptide based AA-MLST allowed the identification of reliable relationships between strains.
| S-EPMC4015679 | biostudies-literature
Project description:Harvest, through its intensity and regulation, often results in selection on female reproductive traits. Changes in female traits can have demographic consequences, as they are fundamental in shaping population dynamics. It is thus imperative to understand and quantify the demographic consequences of changes in female reproductive traits to better understand and anticipate population trajectories under different harvest intensities and regulations. Here, using a dynamic, frequency-dependent, population model of the intensively hunted brown bear (Ursus arctos) population in Sweden, we quantify and compare population responses to changes in four reproductive traits susceptible to harvest-induced selection: litter size, weaning age, age at first reproduction, and annual probability to reproduce. We did so for different hunting quotas and under four possible hunting regulations: (i) no individuals are protected, (ii) mothers but not dependent offspring are protected, (iii) mothers and dependent offspring of the year (cubs) are protected, and (iv) entire family groups are protected (i.e., mothers and dependent offspring of any age). We found that population growth rate declines sharply with increasing hunting quotas. Increases in litter size and the probability to reproduce have the greatest potential to affect population growth rate. Population growth rate increases the most when mothers are protected. Adding protection on offspring (of any age), however, reduces the availability of bears for hunting, which feeds back to increase hunting pressure on the nonprotected categories of individuals, leading to reduced population growth. Finally, we found that changes in reproductive traits can dampen population declines at very high hunting quotas, but only when protecting mothers. Our results illustrate that changes in female reproductive traits may have context-dependent consequences for demography. Thus, to predict population consequences of harvest-induced selection in wild populations, it is critical to integrate both hunting intensity and regulation, especially if hunting selectivity targets female reproductive strategies.
| S-EPMC8549626 | biostudies-literature
Project description:The existence of interindividual differences in personality traits poses a challenge to evolutionary thinking. Although research on the ultimate consequences of personality differences in nonhuman animals has recently undergone a surge of interest, our understanding of whether and how personality influences reproductive decisions in humans has remained limited and informed primarily by modern societies with low mortality-fertility schedules. Taking an evolutionary approach, we use data from a contemporary polygynous high-fertility human population living in rural Senegal to investigate whether personality dimensions are associated with key life-history traits in humans, i.e., quantity and quality of offspring. We show that personality dimensions predict reproductive success differently in men and women in such societies and, in women, are associated with a trade-off between offspring quantity and quality. In women, neuroticism positively predicts the number of children, both between and within polygynous families. Furthermore, within the low social class, offspring quality (i.e., child nutritional status) decreases with a woman's neuroticism, indicating a reproductive trade-off between offspring quantity and quality. Consistent with this, maximal fitness is achieved by women at an intermediate neuroticism level. In men, extraversion was found to be a strong predictor of high social class and polygyny, with extraverted men producing more offspring than their introverted counterparts. These results have implications for the consideration of alternative adaptive hypotheses in the current debate on the maintenance of personality differences and the role of individual factors in fertility patterns in contemporary humans.
| S-EPMC2900694 | biostudies-literature
Project description:Recent studies have uncovered remarkable variation in paternity within primate groups. To date, however, we lack a general understanding of the factors that drive variation in paternity skew among primate groups and across species. Our study focused on hypotheses from reproductive skew theory involving limited control and the use of paternity "concessions" by investigating how paternity covaries with the number of males, female estrous synchrony, and rates of extragroup paternity. In multivariate and phylogenetically controlled analyses of data from 27 studies on 19 species, we found strong support for a limited control skew model, with reproductive skew within groups declining as female reproductive synchrony and the number of males per group increase. Of these 2 variables, female reproductive synchrony explained more of the variation in paternity distributions. To test whether dominant males provide incentives to subordinates to resist matings by extragroup males, that is, whether dominants make concessions of paternity, we derived a novel prediction that skew is lower within groups when threat from outside the group exists. This prediction was not supported as a primary factor underlying patterns of reproductive skew among primate species. However, our approach revealed that if concessions occur in primates, they are most likely when female synchrony is low, as these conditions provide alpha male control of paternity that is assumed by concessions models. Collectively, our analyses demonstrate that aspects of male reproductive competition are the primary drivers of reproductive skew in primates.
| S-EPMC2583106 | biostudies-literature
Project description:When cuckoldry is frequent we can expect fathers to withhold investment in offspring that may not be theirs. Human paternal investment can be substantial and is in line with observations from tens of thousands of conceptions that suggest that cuckoldry is rare in humans. The generality of this claim seems to be in question as the rate of cuckoldry varies across populations and studies have mostly been on Western populations. Two additional factors complicate our conclusions, (1) current estimates of the rate of cuckoldry in humans may not reflect our past behaviour as adultery can be concealed by the use of contraceptives; and (2) it is difficult to obtain samples that are random with respect to their paternity certainty. Studies that combine genealogies with Y-chromosome haplotyping are able to circumvent some of these problems by probing into humans' historical behaviour. Here we use this approach to investigate 1273 conceptions over a period of 330 years in 23 families of the Afrikaner population in South Africa. We use haplotype frequency and diversity and coalescent simulations to show that the male population did not undergo a severe bottleneck and that paternity exclusion rates are high for this population. The rate of cuckoldry in this Western population was 0.9% (95% confidence interval 0.4-1.5%), and we argue that given the current data on historical populations we have to conclude that, at least for Western human populations, cuckoldry rate is probably in the range of 1%.
| S-EPMC4611233 | biostudies-literature
Project description:Optimal foraging behaviour by nectavores is expected to result in a leptokurtic pollen dispersal distribution and predominantly near-neighbour mating. However, complex social interactions among nectarivorous birds may result in different mating patterns to those typically observed in insect-pollinated plants. Mating system, realised pollen dispersal and spatial genetic structure were examined in the bird-pollinated Eucalyptus caesia, a species characterised by small, geographically disjunct populations. Nine microsatellite markers were used to genotype an entire adult stand and 181 seeds from 28 capsules collected from 6 trees. Mating system analysis using MLTR revealed moderate to high outcrossing (tm=0.479-0.806) and low estimates of correlated paternity (rp=0.136±s.e. 0.048). Paternity analysis revealed high outcrossing rates (mean=0.72) and high multiple paternity, with 64 different sires identified for 181 seeds. There was a significant negative relationship between the frequency of outcross mating and distance between mating pairs. Realised mating events were more frequent than expected with random mating for plants <40 m apart. The overall distribution of pollen dispersal distances was platykurtic. Despite extensive pollen dispersal within the stand, three genetic clusters were detected by STRUCTURE analysis. These genetic clusters were strongly differentiated yet geographically interspersed, hypothesised to be a consequence of rare recruitment events coupled with extreme longevity. We suggest that extensive polyandry and pollen dispersal is a consequence of pollination by highly mobile honeyeaters and may buffer E. caesia against the loss of genetic diversity predicted for small and genetically isolated populations.
| S-EPMC5117840 | biostudies-literature
Project description:BackgroundDNA markers are inevitable tools of human identification in forensic science. Single Nucleotide Polymorphisms (SNPs) are one category of these markers which is concerned to use especially in the case of degraded DNA because of their short amplicons.ObjectivesDetection of highly informative SNPs by the criteria is the essential step to develop a useful panel of SNP markers. The purpose of this work is to get high informative SNPs for human identification in Persian ethnic of the Iranian population.Material and methodsGenotype and allele frequencies of 10 SNPs from the SNPforID browser were determined by a PCR-RFLP method on 100 samples that was taken from 100 unrelated Persian people.ResultsThese ten SNPs were in Hardy-Weinberg equilibrium (P value > 0.1) except rs1355366 (P value = 0.02) and Heterozygosity of seven SNPs is greater than 0.45 but minor allele frequency of only four SNPs is more than 0.45. According to criteria only three SNPs rs1454361, rs2111980 and rs2107612 can pass all standards and are highly informative in population for forensic uses.ConclusionsOur data showed that the CPI (Combined probability of Identity) and CPE (Combined Power of Exclusion) for ten SNPs are 1.13 E-04 and 0.809 respectively. It was also showed based on the criteria only three SNPs (rs2107612, rs1454361 and rs2111980) are highly informative in Persian population. If we can find 39 SNPs with PE and PI close to PE and PI of these three SNPs (rs2107612, rs1454361 and rs2111980), we will be able to use of these 39 SNPs in human identification with sufficient power of discrimination.
| S-EPMC7080969 | biostudies-literature
Project description:Many studies investigated variation in the frequency of extrapair paternity (EPP) among individuals. However, our understanding of within-individual variation in EPP remains limited. Here, we comprehensively investigate variation in EPP at the within-individual level in a population of blue tits (Cyanistes caeruleus). Our study is based on parentage data comprising >10 000 genotyped offspring across 11 breeding seasons. First, we examined the repeatability of the occurrence of EPP, the number of extrapair offspring, the number of extrapair partners, and the occurrence of paternity loss using data from males and females that bred in multiple years. Second, we tested whether within-individual changes in EPP between breeding seasons relate to between-year changes in the local social environment. Repeatabilities were generally low but significant for the occurrence and number of extrapair young in females and for whether a male sired extrapair young or not. We found no evidence that the presence of the former social partner or changes in the proportion of familiar individuals or in phenotypic traits of the neighbors influenced changes in levels of EPP in females. However, in adult males, a decrease in the average body size of male neighbors was associated with higher extrapair siring success. If confirmed, this result suggests that the competitive ability of a male relative to its neighbors influences his extrapair mating success. We suggest that alternative hypotheses, including the idea that within-individual changes in EPP are due to "chance events" rather than changes in an individual's social breeding environment, deserve more consideration.
| S-EPMC7689542 | biostudies-literature
Project description:Telomere length is related to aging in many eukaryotes and the rate of telomere attrition has been suggested to reflect individual genetic quality. Telomere length could thus have implications for mate choice. We investigated telomere length variation in bluethroat Luscinia svecica families with mixed paternity, including social parents, extra-pair fathers and nestlings, testing whether telomere length is associated with social and/or extra-pair mate choice through assortative mating or selection of mates with relatively long telomeres. In adults, relative telomere length (rTL) did not differ between the sexes, nor between two age categories. In chicks, however, rTL decreased with body mass at sampling (an index of nestling age). We found a positive correlation between the rTL of social mates, suggesting assortative mating with respect to telomere length or a correlative thereof. However, extra-pair males did not differ from social mates in rTL, and accordingly there was also no difference between within- and extra-pair young (i.e. half-siblings) when controlling for the effect of mass. We found no relationships between telomere length, age and fitness-related traits in adults, but an intriguing year-difference in telomere length in both sexes. In conclusion, we found no support for the idea that females choose extra-pair males based on their telomere length, but social mate choice seems to be influenced by rTL, possibly through its co-variation with aspects reflecting individual quality, like early arrival at the breeding grounds.
| S-EPMC5544213 | biostudies-other