A game theoretic model of kleptoparasitism with strategic arrivals and departures of beetles at dung pats

Dung beetles Onthophagus taurus lay their eggs in brood balls within dung pats. The dung that is used must be sufficiently fresh, and so beetles must keep moving from pat to pat to find fresh dung. If another beetle finds a brood ball it will usually eat the egg inside and lay its own egg in the brood ball instead of constructing its own ball. Thus, beetles will often stay near their eggs to guard them. We model a population of beetles where the times of arrival and departure from pats are strategic choices, and investigate optimal strategies depending upon environmental conditions, which can be reduced to two key parameters, the cost of brood ball construction and the ease of finding balls to parasitise. We predict that beetles should follow one of three distinct behaviors; stay in patches for only short periods, arrive late and be purely parasitic, remain in pats for longer periods in order to guard their brood balls. Under different conditions populations can consist of the first of these types only, a combination of the first and second types, or a combination of all three types

Pupal remodeling and the evolution and development of alternative male morphologies in horned beetles

<p>Abstract</p> <p>Background</p> <p>How novel morphological traits originate and diversify represents a major frontier in evolutionary biology. Horned beetles are emerging as an increasingly popular model system to explore the genetic, developmental, and ecological mechanisms, as well as the interplay between them, in the genesis of novelty and diversity. The horns of beetles originate during a rapid growth phase during the prepupal stage of larval development. Differential growth during this period is either implicitly or explicitly assumed to be the sole mechanism underlying differences in horn expression within and between species. Here I focus on male horn dimorphisms, a phenomenon at the center of many studies in behavioral ecology and evolutionary development, and quantify the relative contributions of a previously ignored developmental process, pupal remodeling, to the expression of male dimorphism in three horned beetle species.</p> <p>Results</p> <p>Prepupal growth is not the only determinant of differences in male horn expression. Instead, following their initial prepupal growth phase, beetles may be extensively remodeled during the subsequent pupal stage in a sex and size-dependent manner. Specifically, male dimorphism in the three <it>Onthophagus </it>species studied here was shaped not at all, partly or entirely by such pupal remodeling rather than differential growth, suggesting that pupal remodeling is phylogenetically widespread, evolutionarily labile, and developmentally flexible.</p> <p>Conclusion</p> <p>This study is the first to document that male dimorphism in horned beetles is the product of two developmentaly dissociated processes: prepupal growth and pupal remodeling. More generally, adult morphology alone appears to provide few clues, if any, as to the relative contributions of both processes to the expression of alternative male morphs, underscoring the importance of developmental studies in efforts aimed at understanding the evolution of adult diversity patterns.</p

Development of functional ectopic compound eyes in scarabaeid beetles by knockdown of orthodenticle

Complex traits like limbs, brains, or eyes form through coordinated integration of diverse cell fates across developmental space and time, yet understanding how complexity and integration emerge from uniform, undifferentiated precursor tissues remains limited. Here, we use ectopic eye formation as a paradigm to investigate the emergence and integration of novel complex structures following massive ontogenetic perturbation. We show that down-regulation via RNAi of a single head patterning gene—orthodenticle—induces ectopic structures externally resembling compound eyes at the middorsal adult head of both basal and derived scarabaeid beetle species (Onthophagini and Oniticellini). Scanning electron microscopy documents ommatidial organization of these induced structures, while immunohistochemistry reveals the presence of rudimentary ommatidial lenses, crystalline cones, and associated neural-like tissue within them. Further, RNA-sequencing experiments show that after orthodenticle down-regulation, the transcriptional signature of the middorsal head—the location of ectopic eye induction—converges onto that of regular compound eyes, including up-regulation of several retina-specific genes. Finally, a light-aversion behavioral assay to assess functionality reveals that ectopic compound eyes can rescue the ability to respond to visual stimuli when wild-type eyes are surgically removed. Combined, our results show that knockdown of a single gene is sufficient for the middorsal head to acquire the competence to ectopically generate a functional compound eye-like structure. These findings highlight the buffering capacity of developmental systems, allowing massive genetic perturbations to be channeled toward orderly and functional developmental outcomes, and render ectopic eye formation a widely accessible paradigm to study the evolution of complex systems.Fil: Zattara, Eduardo Enrique. Indiana University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Macagno, Anna L. M.. Indiana University; Estados UnidosFil: Busey, Hannah A.. Indiana University; Estados UnidosFil: Moczek, Armin P.. Indiana University; Estados Unido

Aktywność fizyczna a otyłość mężczyzn po 60. roku życia

  Introduction and aim of the thesis: Physical activity is indispensible part of healthy lifestyle. However, the majority of elderly people are characterized by low physical activity which can generate variety of illnesses. The aim of the research was to evaluate physical activity of men over 60 years old as well as to evaluate the connection between this activity and obesity. Materials and methods: The research was conducted on the group of 25 men over 60 years old. The physical activity was measured as weekly number of steps with the use of pedom­eters. Somatic parameters (BH, BM, WC, %FAT) were evaluated. BMI and WHR were cal­culated. Results: Only 33.33% old men had physical activity on levels rec ommended for healthy lifestyle. Most men in the in the evaluated group had too much body mass (over weight 45,83%, obesity 37,5%). Negative, high correlations were observed between the physical activity and body mass indexes (BM, WC, %FAT, BMI,WHR). Conclusions: Evaluated men usually led sedentar y lifestyle or had low physical activi ty which led to overweight and obesity. It may appear that pro-health projects dedicated for men over 60 years old are not enough.  Wprowadzenie i cel pracy: Aktywność fizyczna jest nieodzownym elementem zdrowego stylu życia. Tym niemniej większość osób w starszym wieku cechuje niska aktywność fizyczna, co może generować występowanie różnorakich chorób. Celem badań była ocena aktywności fizycznej mężczyzn po 60. roku życia oraz zbadanie jej związku z występowaniem otyłości. Materiał i metody: Badaniami objęto 25 mężczyzn po 60. roku życia. Aktywność fizyczną oceniono tygodniową liczbą kroków policzonych z wykor zystaniem krokomierzy. Ocenie poddano parametry somatyczne (BH, BM, WC, %FAT). Obliczono wskaźniki BMI i WHR. Wyniki: Zaledwie 33,33% mężczyzn cechowała aktywność fizyczna na rekomendowanym dla zdrowia poziomie. W badanej grupie większość badanych cecho wała się nadmiarem masy ciała (nadwaga 45,83%, otyłość 37,5%). Zaobserwowano ujemne, wysokie korelacje (r = –0,6) pomiędzy aktywnością fizyczną, a wskaźnikami masy ciała (BM, WC, %FAT, BMI, WHR). Wnioski: Badani mężczyźni cechowali się w większości siedzącym trybem życia lub niską aktywnością fizyczną, co miało związek z występowaniem nadwagi lub otyłości. Wydaje się, że programy prozdrowotne kierowane do mężczyzn po 60. roku życia są niewystarczające

Threshold Evolution in Exotic Populations of a Polyphenic Beetle

Polyphenic development is thought to play an important role in the evolution of phenotypic diversity and morphological novelties, yet the evolution of polyphenisms has rarely been documented in natural populations. Here we compare the morphologies of male dung beetles (Onthophagus taurus; Coleoptera: Scarabaeidae) from populations introduced to Australia and the eastern United States. Males in this species express two alternative morphologies in response to larval feeding conditions. Males encountering favourable conditions grow larger than a threshold body size and develop a pair of horns on their heads, whereas males that encounter poor conditions do not reach this threshold size and remain hornless. Australian and US populations did not differ in overall body size ranges, but exhibited significant differences in the location of the critical body size threshold that separates alternative male morphs. Australian males remained hornless at much larger body sizes than males in US populations, resulting in substantial and significant differences in the average body size-horn length allometry between exotic populations, as well as significant differences in morph ratios. The phenotypic divergence observed between field populations was maintained in laboratory populations after two generations under identical environmental conditions, suggesting a genetic basis to allometric divergence in these populations. Divergence between exotic O. taurus populations was of a magnitude and kind typically observed between species. We use our results to examine potential causes of allometric divergence in onthophagine beetles, and discuss the evolutionary potential of threshold traits and polyphenic development in the origin of morphological and behavioural diversity

Psychologische Methoden zur Landschaftsbildbewertung für Landschaftsplaner*innen

Im Rahmen eines dreistufigen Seminars, welches im Sommersemester 2017 gemeinsam von einem Landschaftsplaner und einer Psychologin durchgeführt wurde, lernten zwölf Studierende im ersten Teil verschiedene Methoden zur Landschaftsbildbewertung kennen. Das Lernziel war es, sich zunächst systematisch mit der sogenannten Laienperspektive zu beschäftigen, um diese im Rahmen der Landschaftsplanung einbeziehen zu können. Dazu führten die Studierenden in vier Kleingruppen qualitative und quantitative Umfragen mit jeweils rund 40 Teilnehmenden durch, werteten diese aus und präsentierten sie ihren Mitstudierenden. Damit die Studien einen hohen Anwendungsbezug hatten, stand im Mittelpunkt der Einfluss von Landschaften auf den Menschen und seine Bedürfnisse nach Erholung, Wohlbefinden, Gesundheit, Lebensqualität und dem Erleben landschaftlicher Schönheit. Im zweiten Teil des Seminars stand die Rolle der Expert*innen im Mittelpunkt und die Frage, wie valide und reliabel die Urteile von Studierenden der Landschaftsplanung als angehenden Expert*innen sind. Dazu bewerteten Studierenden zu drei Zeitpunkten im Semester die gleichen sechs Fotos nach den landschaftsplanerischen Kriterien Vielfalt, Eigenart, Schönheit und Erholungswert. Zwischen den Bewertungen wurden sie ausführlich im Verstehen und Anwenden dieser Kriterien geschult. Wie erwartet, wurden die Urteile der Studierenden mit jeder Messwiederholung ähnlicher, die Effekte waren aber gering. Die weiterhin bestehenden Unterschiede der Ergebnisse deuten darauf hin, dass auch (angehende) Expert*innen keine einheitlichen und stabilen Bewertungen in Bezug auf die Kriterien fällen und es daher in der Praxis sinnvoll ist, mehrere Urteile einzuholen. Im dritten Teil waren die Studierenden gebeten, insgesamt 60 Fotos des Forschungsprojektes „Szenarien für den Ausbau der Erneuerbaren Energien aus Naturschutzsicht“ hinsichtlich Vielfalt, Eigenart, Schönheit, Erholung und Naturnähe zu bewerten. Sie unterstützten das Forschungsprojekt durch ihre Urteile, und die Ergebnisse zeigten einen weiteren Schritt in deren Professionalisierung. Allerdings wurden erneut Schwächen der verwendeten Kriterien deutlich, denn die Urteile in Bezug auf Vielfalt, Eigenart und Schönheit sowie Erholungswert korrelieren hoch miteinander, sie messen also nicht trennscharf. Die Veranstaltung ermöglichte insbesondere durch ihren dialogischen Charakter ein gemeinsames Lernen und entsprechende Erfolgserlebnisse. Deutlich ergänzt wurden die bereits bei den Studierenden vorhandenen planerischen Kompetenzen um Theorien und Methoden sozialwissenschaftlicher Disziplinen. Insbesondere die Anwendung ermöglichte eine entsprechende Reflektion und Problemorientierung, die ohne die eigenen praktischen Erfahrungen mit verschiedenen erlernten Methoden nicht möglich gewesen wäre. Schließlich führte das bewusste Wahrnehmen anderer Positionen zum Thema Landschaft zu einer besseren Einordnung des planerischen Handelns. (DIPF/Orig.

EST and microarray analysis of horn development in Onthophagus beetles

<p>Abstract</p> <p>Background</p> <p>The origin of novel traits and their subsequent diversification represent central themes in evo-devo and evolutionary ecology. Here we explore the genetic and genomic basis of a class of traits that is both novel and highly diverse, in a group of organisms that is ecologically complex and experimentally tractable: horned beetles.</p> <p>Results</p> <p>We developed two high quality, normalized cDNA libraries for larval and pupal <it>Onthophagus taurus </it>and sequenced 3,488 ESTs that assembled into 451 contigs and 2,330 singletons. We present the annotation and a comparative analysis of the conservation of the sequences. Microarrays developed from the combined libraries were then used to contrast the transcriptome of developing primordia of head horns, prothoracic horns, and legs. Our experiments identify a first comprehensive list of candidate genes for the evolution and diversification of beetle horns. We find that developing horns and legs show many similarities as well as important differences in their transcription profiles, suggesting that the origin of horns was mediated partly, but not entirely, by the recruitment of genes involved in the formation of more traditional appendages such as legs. Furthermore, we find that horns developing from the head and prothorax differ in their transcription profiles to a degree that suggests that head and prothoracic horns are not serial homologs, but instead may have evolved independently from each other.</p> <p>Conclusion</p> <p>We have laid the foundation for a systematic analysis of the genetic basis of horned beetle development and diversification with the potential to contribute significantly to several major frontiers in evolutionary developmental biology.</p