Analysing convergence, consistency and trajectory of Artificial Bee Colony Algorithm

Recently, swarm intelligence based algorithms gained attention of the researchers due to their wide applicability and ease of implementation. However, much research has been made on the development of swarm intelligence algorithms but theoretical analysis of these algorithms is still a less explored area of the research. Theoretical analyses of trajectory and convergence of potential solutions towards the equilibrium point in the search space can help the researchers to understand the iteration-wise behaviour of the algorithms which can further help in making them efficient. Artificial Bee Colony (ABC) optimization algorithm is swarm intelligence based algorithm. This paper presents the convergence analysis of ABC algorithm by using results from the theory of dynamical system and convergent boundaries for the parameters $\phi$ and $\psi$ is proposed. Also the trajectory of potential solutions in the search space is analysed by obtaining a partial differential equation corresponding to the position update equation of ABC algorithm. The analysis reveals that the ABC algorithm performs better/efficiently when parameters $\phi$ and $\psi$ are in the convergent region and potential solutions movement follows 1-Dimensional advection equation

Behavioural Genetics and Social Environment in the Small Carpenter Bee, Ceratina Calcarata

Most bees are solitary but the eastern small carpenter bee, Ceratina calcarata, are both subsocial and facultatively social. Females form associations of parents and a single generation of offspring, often including a smaller under provisioned dwarf eldest daughter (DED) who feeds her adult siblings. To study the influence of social environment on this species, firstly, observation nests were constructed, and secondly, I conducted an experiment in the field to compare gene expression profiles among ages and phenotypes of foraging females. Observation nests were treated by removing either only mothers, or both mothers and DEDs. In the absence of mothers offspring were more tolerant, and aggression was significantly greater in the absence of both mother and DED. Here I also present brain gene expression profiles of foraging mothers, DEDs in the presence and absence of mothers, and regular daughters. I found significant differences in gene expression associated with age, size and social environment

The evolution and mechanisms of caste plasticity in vespid wasps

Social insects are ecologically dominant predators, pollinators, herbivores and detritivores across many terrestrial ecosystems. Key to the ecological success of these species is a uniquely strong division of labour between reproductives (‘queens’) and non-reproductives (‘workers’). In some social insect species, reproductive division of labour is obligate and developmentally determined, but many other taxa possess full reproductive plasticity, which is the basal state for social insect evolution. Answering the question of how division of reproductive labour is maintained in the presence of reproductive plasticity is an important prerequisite to understanding how and why this plasticity has been lost in the most derived social insect taxa. In this thesis, I address this question using two species of social wasp which exhibit strong division of reproductive labour but full reproductive plasticity. Two chapters of the thesis examine responses to queen loss in the European paper wasp P. dominula, in order to understand the mechanisms by which groups accommodate the loss of a reproductive. In Chapter 2 I show that in this species, groups generate replacement reproductives rapidly and with little conflict by relying on an age-based succession criterion. In Chapter 3 I analyse the transcriptomic mechanisms that underlie this succession process, and show that variation in individuals’ phenotypes only partially explains their transcriptomic responses, a result that suggests hidden costs of queen loss. In Chapter 4, I analyse individual-level transcriptomic data from a facultatively social tropical hover wasp, Liostenogaster flavolineata, which forms linearly age-based dominance hierarchies in which individuals exhibit progressively reduced foraging effort as they move up in rank. I show that despite differences in social structure, variation in gene expression in colonies of this species is surprisingly similar to that of obligately social species such as P. dominula. I also find that genes that are associated with indirect fitness in L. flavolineata are more strongly evolutionarily conserved than genes associated with direct fitness, a surprising result that runs counter to results obtained for other social insect species. Additionally, in Chapter 5 I argue for a reconceptualization of the loss of reproductive plasticity that has occurred in more complex insect societies. Taken as a whole, this thesis sheds light on the behavioural and transcriptomic mechanisms by which distinct fitness strategies are maintained in reproductively skewed societies as well as revealing potential limitations of these mechanisms, emphasising the value of reproductively plastic social insects as models for the evolution of sociality

Divergent Mating Behaviors and the Evolution of Reproductive Isolation

Sexual selection can cause rapid co-divergence of mating traits and mate preferences, generate reproductive barriers among individuals bearing divergent mating traits, and potentially lead to speciation. In my dissertation, I focused on two emerging topics that challenge this traditional speciation-by-mate-choice paradigm. First, sexual selection encompasses both mate preferences and intrasexual competition, yet speciation research disproportionally focused on the role of the former. Second, sexual behaviors are usually assumed to be genetically inherited, but they may often be shaped by learning instead, which can generate very different evolutionary trajectories for traits and preferences. Using studies of the highly polymorphic strawberry poison frogs (Oophaga pumilio), I demonstrated how incorporating (i) male-male competition and (ii) behavioral learning can enhance our understanding of the potential for speciation to be driven by sexual selection. I first characterized behavioral patterns across a natural contact zone between color morphs and showed that coloration (the divergent mating trait) mediates both female choice and male-male competition. Females often prefer males of their own (local) color over a novel color, and males, when defending territories, are more aggressive against their own color morph. I then tested how these color-mediated female preferences and male aggression biases interact to determine mating patterns. I conducted a controlled breeding experiment in which male-male competition and female mate choice act either in same or in opposing directions. In this study, females reproduced more often with the territorial male over the non-territorial male, regardless of the males’ coloration. This challenges the common assumption that knowledge of female preferences for male mating traits is sufficient to predict mating patterns. Finally, I discovered that learning from mothers during the tadpole stage shapes both female mate preferences and male aggression biases in O. pumilio. Based on this finding, I built a population genetic model and used it to demonstrate a simple and elegant mechanism by which sexual selection alone has the potential to initiate speciation. My research highlights the importance of considering interactions between mate choice, intrasexual competition, and behavioral learning, for studies of mating trait evolution and sexual selection’s role in speciation

The evolutionary dynamics of intralocus sexual conflict

Males and females often have divergent evolutionary interests, sparking two forms of sexual conflict: 1) interlocus sexual conflict (IRSC), an antagonistic interaction between the sexes that is mediated by different loci in each sex; 2) intralocus sexual conflict (IASC), where genes have opposite fitness consequences depending on the sex expressing them. Both forms of conflict appear to be common, yet there are large gaps in our understanding of their evolutionary dynamics. I focus on IASC and begin by synthesising theoretical concepts and empirical findings to better understand its evolutionary dynamics in a critical review of the topic (Chapter 1). I take a multifaceted approach by considering the maintenance, resolution, and consequences of this evolutionary feud. I then explore the extent of sexually antagonistic genetic variation for fitness in a large-scale study of Drosophila melanogaster, using hemiclonal analysis (Chapter 2). I compare results to data collected from the same population five years previously and show that the strength of the conflict has declined over time. Next, I show that subtle changes in temperature during the adult life-stage can dramatically affect sex-specific fitness and alter the direction of the conflict, which could contribute to the maintenance of IASC in natural populations (Chapter 3). I also present a new theoretical model that incorporates IASC into traits that are involved in IRSC arms races (Chapter 4). Surprisingly, IASC can have dramatic and contrasting effects on sexually antagonistic coevolution: stabilising arms races or drawing the sexes into repeated bouts of arms race escalation and stasis. Finally, I extend IASC theory to explore an analogous conflict between castes in social animal societies (Chapter 5) and suggest unique research opportunities to be capitalised upon in species with a division of labour. I summarise the work in this thesis by highlighting the broad and varied biological consequences of such a pervasive conflict (Chapter 6)

Venom Yield, Regeneration, and Composition in the Centipede Scolopendra Polymorpha

In this dissertation, I investigated yield, regeneration, and composition of centipede venom. In the first of three empirical studies, I investigated how size influenced venom volume yield and protein concentration in Scolopendra polymorpha and S. subspinipes. I also examined additional potential influences on yield in S. polymorpha, including relative forcipule size, relative mass, geographic origin, sex, time in captivity, and milking history. Volume yield was positively linearly related to body length in both species; however, body length and protein concentration were uncorrelated. In S. polymorpha, yield was most influenced by body length, but was also positively associated with relative forcipule length and relative body mass. In the second study, I investigated venom volume and total protein regeneration during the 14-day period subsequent to venom extraction in S. polymorpha. I further tested the hypothesis that venom protein components, separated by RP-FPLC, undergo asynchronous synthesis. During the first 48 hours, volume and protein mass increased linearly. However, protein regeneration lagged behind volume regeneration, with only 65–86% of venom volume and 29–47% of protein mass regenerated during the first 2 days. No significant additional regeneration occurred over the subsequent 12 days. Analysis of chromatograms of individual venom samples revealed that five of 10 chromatographic regions and 12 of 28 peaks demonstrated changes in percent of total peak area among milking intervals, indicating that venom proteins are regenerated asynchronously. In the third study, I characterized the venom composition of S. polymorpha using proteomic methods. I demonstrated that the venom of S. polymorpha is complex, generating 23 bands by SDS-PAGE and 56 peaks by RP-FPLC. MALDI TOF MS revealed hundreds of components with masses ranging from 1014.5 to 82863.9 Da. The distribution of molecular masses was skewed toward smaller peptides and proteins, with 72% of components found below 12 kDa. BLASTp sequence similarity searching of MS/MSderived amino acid sequences demonstrated 20 different sequences with similarity to known venom components, including serine proteases, ion-channel activators/inhibitors, and neurotoxins. In Appendix A, I reviewed how animals strategically deploy various emissions, including venom, highlighting how the metabolic and ecological value of these emissions leads to their judicious use

Iowa Conservationist, October 1991, Vol. 50, no.10

This newsletter is produced by the Iowa Department of Natural Resources, formally Iowa State Conservation Commission. This newsletter contains news and stories relating to all aspects of hunting, fishing, trapping, conservation and utilizing the outdoor resources of Iowa