128 research outputs found
The causes and consequences of kin recognition in the cooperatively breeding cichlid Neolamprologus pulcher
Kin recognition allows individuals to assess their relatedness to conspecifics, thus they may then show kin discrimination and make informed choices as to with whom to associate and/or breed. Cooperatively breeding species, such as the cichlid Neolamprologus pulcher, are an excellent model system for investigating kin recognition, as they live in complex social groups, containing both kin and non-kin group members. Cooperation involves individuals helping to rear the offspring of the dominant pair. Helping is costly, but helpers may gain direct fitness benefits through living in a group, and if they aid relatives, they can also gain indirect fitness benefits through kin selection. Furthermore, by being able to recognise kin, individuals can also avoid inbreeding and the potentially deleterious consequences of it. Thus, N. pulcher are predicted to have good kin recognition abilities. In this thesis, I investigate kin recognition and its consequences for helping and mate choice in a captive population of N. pulcher. In chapter 2, I investigated the kin recognition capabilities of juvenile N. pulcher whilst controlling for familiarity. I found that N. pulcher preferred to associate with unfamiliar kin over unfamiliar non-kin. Kin recognition was via some form of phenotype matching, with chemical cues being more important than visual cues. Additionally, I found no discrimination between familiar and unfamiliar kin; thus, relatedness rather than familiarity was important in the association preferences of juvenile N. pulcher. Chapter 3 explored whether relatedness to the breeding pair, or differences in individual behavioural types affected the amount or type of helping shown by N. pulcher. Controlling for group size and helper relatedness, I found that the relatedness of the helpers to the breeders had no influence on the amount or type of help carried out. Thus, kin selected benefits alone cannot explain variation in helping behaviour in N. pulcher. The amount of territory maintenance carried out correlated with the amount of territory defence, thus, some individuals were consistently helpful. Individuals varied consistently in their aggressiveness, risk-responsiveness and activity levels, but these traits did not correlate with one another. More aggressive, risk-prone or more active helpers carried out more territory defence than submissive, risk-averse or inactive helpers. In contrast, the amount of territory maintenance carried out by helpers, was not correlated with the behavioural types. Thus, differences in behavioural types explained more variation in helping behaviour in N. pulcher than relatedness. Since motivation to associate with kin might vary with age and individual state, in chapter 4, I investigated whether N. pulcher avoided kin when sexually mature, and examined the fitness consequences of inbreeding. In standard two-way choice tests, I found that whilst male N. pulcher showed no preferences for associating with sisters over female non-kin, female N. pulcher preferred to associate with brothers over male non-kin. However, when given the opportunity to breed, latency to breed and hatching success did not differ between brother-sister pairs and unrelated pairs. Thus, in N. pulcher inbreeding is not actively avoided and does not appear to be detrimental to fitness. I suggest that sex-biased dispersal and regular breeder replacement on territories may minimise the occurrences of inbreeding in the wild and that inbreeding may be opportunistic, rather than a strategic decision. The final theme of my thesis investigated the effect of phenotypic traits on mate choice. In N. pulcher (chapter 4) I found that the size of an individual’s facial stripe, which varies between individuals, played no role in mate association preferences. I then investigated male mate choice for female body size in the non-cooperatively breeding green swordtail, Xiphophorus hellerii. In chapter 5, I found that males showed preferences for large over small females when presented only with visual cues, but not with only chemical cues. However, as the size differential between the large and small female increased, males showed preferences for the larger female based on chemical cues. So, male X. hellerii prefer larger females, which are predicted to be more fecund and hence, bring them greater fitness returns. In conclusion, my study has shown that N. pulcher can recognise kin, but the ability to do this does not compel individuals to show kin directed cooperation, or inbreeding avoidance. Instead, factors such as an individual’s behavioural type have more influence on decisions to help, and inbreeding does not appear to be detrimental to fitness. Overall, this project shows that under the conditions we tested, kin selection alone does not drive the social interactions in N. pulcher groups. Further, it highlights the need to consider multiple factors affecting an individual’s fitness, in order to fully understand why different species show a propensity to recognise and discriminate between kin and non-kin
Development of a Faculty Learning Community to support Scholarship and Feedback
In an effort to explore the ideas of Scholarship of Learning and Teaching, and to comply with Glasgow’s University’s career development programme, a small group of academics from the College of Medicine, Veterinary and Life Sciences established a Learning Community. The LC has several aims:
• To create and design a Learning Community to support scholarship and progression for lecturers on learning & teaching track
• To understand how a Learning Community can be used to support staff on career development pathways
• To empower participants to engage in the University’s career development programme through peer support and peer mentorship within the Learning Community
• provide practical support for scholarship projects (it is hoped that all members will be supported to drive their scholarship ‘from idea to manuscript’)
It is hoped that through the sharing of ideas, and collaboration between schools, the LC hope to publish and disseminate scholarship, and provide a series of recommendations regarding scholarship support. Planned scholarship outputs include papers in educational journals, conference abstracts and presentations, and a significant ambition to influence policy within the university regarding scholarship and career development
Cystic fibrosis bone disease: Pathophysiology, assessment and prognostic implications.
Cystic fibrosis bone disease (CFBD) is a common long-term complication of cystic fibrosis (CF) that can lead to increased fractures and significant morbidity and mortality in this patient population. CFBD pathophysiology remains poorly understood and is likely to be multifactorial. There are limited studies evaluating diagnostic tools and tests to guide therapeutic decisions and monitoring of CFBD. This review will present and discuss the current evidence
Confused About Scholarship and ECDP? (Us too!) A Possible Solution!
In an effort to explore the ideas of Scholarship of Learning and Teaching, and to comply with Glasgow’s University’s career development programme, a small group of academics from the College of Medicine, Veterinary and Life Sciences established a Learning Community. The LC has several aims:
• To create and design a Learning Community to support scholarship and progression for lecturers on learning & teaching track
• To understand how a Learning Community can be used to support staff on career development pathways
• To empower participants to engage in the University’s career development programme through peer support and peer mentorship within the Learning Community
• provide practical support for scholarship projects (it is hoped that all members will be supported to drive their scholarship ‘from idea to manuscript’)
It is hoped that through the sharing of ideas, and collaboration between schools, the LC hope to publish and disseminate scholarship, and provide a series of recommendations regarding scholarship support. Planned scholarship outputs include papers in educational journals, conference abstracts and presentations, and a significant ambition to influence policy within the university regarding scholarship and career development
Effects of territorial damselfish on corallivorous fish assemblage composition and coral predation in the Mauritian lagoon
Predation is a significant stressor for many coral species. Understanding how predation interacts with factors such as climate change is key to coral conservation. Territorial damselfish of the genus Stegastes form territories on branching corals (genus Acropora) on which they cultivate algae, and while defending these territories, provide corals with indirect protection from predation. However, it is not known how the protection afforded by Stegastes spp. varies with corallivorous fish assemblage composition, nor whether corallivore assemblages themselves may be affected by the presence of Stegastes spp. and their associated Acropora spp. habitats. This study examined relationships among predation protection by Stegastes spp., branching Acropora coral cover, and the number and species richness of corallivorous fish present within a given area, namely the Mauritian lagoon in the western Indian Ocean. Predation on bleaching-resilient massive Porites lutea corals within and outside Stegastes territories was surveyed at sites around Mauritius island. Corallivorous fish assemblages, branching coral cover, and Stegastes spp. density were also surveyed at each site visit. Results show that high predation was correlated with the presence of high numbers of corallivores, but predation was lower within Stegastes spp. territories irrespective of all observed corallivore densities. Greater numbers of Stegastes spp. were correlated with increasing density of obligate corallivores. Non-Acroporid coral cover was positively correlated with species richness of obligate corallivores, while branching Acropora coral cover was negatively correlated with overall corallivore density. This study shows for the first time that predation on bleaching-resilient massive corals is lower within Stegastes spp. territories regardless of the number of corallivores present, adding to the growing body of knowledge on the complex relationships between Stegastes spp. and their environment. The findings also indicate possible effects of the presence of Stegastes spp. and their branching Acropora habitats on corallivorous fish density in areas with low coral diversity, which may warrant further study
Paternity of Subordinates Raises Cooperative Effort in Cichlids
Background
In cooperative breeders, subordinates generally help a dominant breeding pair to raise offspring. Parentage studies have shown that in several species subordinates can participate in reproduction. This suggests an important role of direct fitness benefits for cooperation, particularly where groups contain unrelated subordinates. In this situation parentage should influence levels of cooperation. Here we combine parentage analyses and detailed behavioural observations in the field to study whether in the highly social cichlid Neolamprologus pulcher subordinates participate in reproduction and if so, whether and how this affects their cooperative care, controlling for the effect of kinship.
Methodology/Principal Findings
We show that: (i) male subordinates gained paternity in 27.8% of all clutches and (ii) if they participated in reproduction, they sired on average 11.8% of young. Subordinate males sharing in reproduction showed more defence against experimentally presented egg predators compared to subordinates not participating in reproduction, and they tended to stay closer to the breeding shelter. No effects of relatedness between subordinates and dominants (to mid-parent, dominant female or dominant male) were detected on parentage and on helping behaviour.
Conclusions/Significance
This is the first evidence in a cooperatively breeding fish species that the helping effort of male subordinates may depend on obtained paternity, which stresses the need to consider direct fitness benefits in evolutionary studies of helping behaviour
Helpers influence on territory use and maintenance in Alpine marmot groups
In social mammals, territory size and shape vary according to the number and strength of neighbour individuals competing for resources. Two main theories have been proposed to explain this variability: the Group Augmentation (GA) and the realized Resource Holding Potential (rRHP) hypotheses. The first states that the outcome of the interactions among groups depends on the total number of individuals in the group while the second states that only the number of animals directly involved in intergroup competition determines this outcome. We collected data on space use of individually tagged Alpine marmots ( Marmota marmota), a cooperative breeding species that overlaps part of its territory with neighbouring groups. In accordance with the rRHP hypothesis, we found that groups having higher proportion of helpers, rather than higher total number of individuals, had lower percentage of the territory overlapping with neighbouring groups and a larger area available for individual exclusive use
Race/ethnicity and socio-economic differences in colorectal cancer surgery outcomes: analysis of the nationwide inpatient sample
The causes and consequences of inbreeding avoidance and tolerance in cooperatively breeding vertebrates
Cooperative breeders provide a particularly interesting scenario for studying inbreeding. Such populations are viscous due to delayed dispersal and short dispersal distances, resulting in the build-up of relatives in the local population. This leads to a high risk of inbreeding, and consequently of inbreeding depression. This has driven the evolution of an array of inbreeding avoidance mechanisms resulting in a relatively low level of close inbreeding in the majority of cooperative breeders. However, there are a number of species where inbreeding occurs relatively frequently. The presence of regular inbreeding (in cases where inbreeding is not a result of recent population declines), suggests that inbreeding tolerance and even preference can evolve under some circumstances. Both inbreeding and inbreeding avoidance mechanisms have enormous downstream fitness consequences for cooperative breeding species. For example, they can influence reproductive dynamics leading to a monopolisation of breeding opportunities by dominant individuals. Inbreeding and its avoidance are also likely to impact on the evolution of cooperative breeding itself through influencing levels of relatedness between potential cooperators. Finally, in some cooperative breeders, a high degree of inbreeding avoidance can be detrimental to population viability, and hence is of particular concern to conservationists. In this review, I discuss these issues in detail and also briefly consider recent advances in the methods available for the study of inbreeding in natural populations
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