scholarly journals Sexual conflict in twins: male co-twins reduce fitness of female Soay sheep

2009 ◽  
Vol 5 (5) ◽  
pp. 663-666 ◽  
Author(s):  
Peter Korsten ◽  
Tim Clutton-Brock ◽  
Jill G. Pilkington ◽  
Josephine M. Pemberton ◽  
Loeske E. B. Kruuk
Keyword(s):  
Sex Allocation ◽  
Limited Resources ◽  
First Year ◽  
Specific Interactions ◽  
Soay Sheep ◽  
Sibling Interactions ◽  
Survival And Reproduction ◽  
Males And Females ◽  
Long Term Consequences

Males and females often have different requirements during early development, leading to sex-specific interactions between developing offspring. In polytocous mammals, competition for limited resources in utero may be asymmetrical between the sexes, and androgens produced by male foetuses could have adverse effects on the development of females, with potentially long-lasting consequences. We show here, in an unmanaged population of Soay sheep, that female lambs with a male co-twin have reduced birth weight relative to those with a female co-twin, while there was no such effect in male twins. In addition, females with a male co-twin had lower lifetime breeding success, which appeared to be mainly driven by differences in first-year survival. These results show that sex-specific sibling interactions can have long-term consequences for survival and reproduction, with potentially important implications for optimal sex allocation.

scholarly journals Mutation load decreases with haplotype age in wild Soay sheep

2021 ◽  
Author(s):  
M.A. Stoffel ◽  
S.E. Johnston ◽  
J.G. Pilkington ◽  
J.M Pemberton
Keyword(s):  
Inbreeding Depression ◽  
Purifying Selection ◽  
Small Population ◽  
First Year ◽  
Mutation Load ◽  
Soay Sheep ◽  
Recessive Mutations ◽  
Deleterious Alleles ◽  
Lower Population

AbstractRuns of homozygosity (ROH) are pervasive in diploid genomes and expose the effects of deleterious recessive mutations, but how exactly these regions contribute to variation in fitness remains unclear. Here, we combined empirical analyses and simulations to explore the deleterious effects of ROH with varying genetic map lengths in wild Soay sheep. Using a long-term dataset of 4,592 individuals genotyped at 417K SNPs, we found that inbreeding depression increases with ROH length. A 1% genomic increase in long ROH (>12.5cM) reduced the odds of first-year survival by 12%, compared to only 7% for medium ROH (1.56-12.5cM), while short ROH (<1.56cM) had no effect on survival. We show by forward genetic simulations that this is predicted: compared with shorter ROH, long ROH will have higher densities of deleterious alleles, with larger average effects on fitness and lower population frequencies. Taken together, our results are consistent with the idea that the mutation load decreases in older haplotypes underlying shorter ROH, where purifying selection has had more time to purge deleterious mutations. Finally, our study demonstrates that strong inbreeding depression can persist despite ongoing purging in a historically small population.

scholarly journals Implanted satellite transmitters affect sea duck movement patterns at short and long timescales

The Condor ◽  
2020 ◽  
Vol 122 (3) ◽  
Author(s):  
Juliet S Lamb ◽  
Peter W C Paton ◽  
Jason E Osenkowski ◽  
Shannon S Badzinski ◽  
Alicia M Berlin ◽  
...  
Keyword(s):  
Breeding Site ◽  
Behavioral Changes ◽  
First Year ◽  
Behavioral Patterns ◽  
Telemetry Data ◽  
Short Term ◽  
Satellite Transmitters ◽  
Males And Females ◽  
Long Timescales

Abstract Studies of the effects of transmitters on wildlife often focus on survival. However, sublethal behavioral changes resulting from radio-marking have the potential to affect inferences from telemetry data and may vary based on individual and environmental characteristics. We used a long-term, multi-species tracking study of sea ducks to assess behavioral patterns at multiple temporal scales following implantation of intracoelomic satellite transmitters. We applied state-space models to assess short-term behavioral patterns in 476 individuals with implanted satellite transmitters, as well as comparing breeding site attendance and migratory phenology across multiple years after capture. In the short term, our results suggest an increase in dispersive behavior immediately following capture and transmitter implantation; however, behavior returned to seasonally average patterns within ~5 days after release. Over multiple years, we found that breeding site attendance by both males and females was depressed during the first breeding season after radio-marking relative to subsequent years, with larger relative decreases in breeding site attendance among males than females. We also found that spring and breeding migrations occurred later in the first year after radio-marking than in subsequent years. Across all behavioral effects, the severity of behavioral change often varied by species, sex, age, and capture season. We conclude that, although individuals appear to adjust relatively quickly (i.e. within 1 week) to implanted satellite transmitters, changes in breeding phenology may occur over the longer term and should be considered when analyzing and reporting telemetry data.

scholarly journals Transition and adjustment of students to the university environment

2018 ◽  
Vol 34 (11) ◽  
Author(s):  
Katica Lacković-Grgin ◽  
Izabela Sorić
Keyword(s):  
Self Esteem ◽  
Stressful Event ◽  
First Year ◽  
Student Body ◽  
Psychological Variables ◽  
University Environment ◽  
Long Term Consequences ◽  
The University ◽  
Assessment Of Stress

A sample of the student body of the Faculty of Philosophy was given two inquiries: one upon enrolment at the Faculty and another after the first year of study. The aim of the research was to establish the nature of loneliness amongst students, the durability of the effect of moving from home, and the effect of financial and educational burdens on the self-esteem and loneliness of students. The authors desired to establish which of diese variables, coupled with other personal and enviromental factors, reliably prognosticate the student's adjustment to the university. The indicators of adjustment were the satisfaction with achievement and the assessment of stress during the first year of study. The results show that loneliness amongst students is situational which validates the assumption that separation from significant persons is a stressful event but without durable effects on loneliness. Self-esteem was shown to be stable while the effects of educational burdens on self- respect proved lasting. In addition, self-esteem, just as the removal from home, showed itself to be a good predictor both regarding satisfaction with achievement and stress during die first year of study. On the basis of their findings, the authors suggest that in order to investigate the short-termed consequences of entering the university one ought to choose those psychological variables which represent states while for the prediction of long-term consequences traits should be chosen.

Barriers to Physical Activity in Adolescents

2015 ◽  
Vol 23 (2) ◽  
pp. 47-59 ◽  
Author(s):  
Nadine Langguth ◽  
Tanja Könen ◽  
Simone Matulis ◽  
Regina Steil ◽  
Caterina Gawrilow ◽  
...  
Keyword(s):  
Physical Activity ◽  
Leisure Activities ◽  
Outcome Expectations ◽  
Multidimensional Approach ◽  
Factor Analyses ◽  
Physical And Mental Health ◽  
Tailored Interventions ◽  
Long Term Consequences ◽  
Age Range

During adolescence, physical activity (PA) decreases with potentially serious, long-term consequences for physical and mental health. Although barriers have been identified as an important PA correlate in adults, research on adolescents’ PA barriers is lacking. Thus reliable, valid scales to measure adolescents’ PA barriers are needed. We present two studies describing a broad range of PA barriers relevant to adolescents with a multidimensional approach. In Study 1, 124 adolescents (age range = 12 – 24 years) reported their most important PA barriers. Two independent coders categorized those barriers. The most frequent PA barriers were incorporated in a multidimensional questionnaire. In Study 2, 598 adolescents (age range = 13 – 21 years) completed this questionnaire and reported their current PA, intention, self-efficacy, and negative outcome expectations. Seven PA barrier dimensions (leisure activities, lack of motivation, screen-based sedentary behavior, depressed mood, physical health, school workload, and preconditions) were confirmed in factor analyses. A multidimensional approach to measuring PA barriers in adolescents is reliable and valid. The current studies provide the basis for developing individually tailored interventions to increase PA in adolescents.

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