Defense behavior of three, free living giant (Megapis) honey bee subspecies, Apis laboriosa, A. dorsata dorsata and A. dorsata breviligula, was compared. Disturbed worker bees responded with characteristic dorso-ventral defense body twisting (DBT). Workers of A. laboriosa twisted the thorax by 55°, and the two other A. dorsata subspecies by about 10° more. A. laboriosa workers raised the tip of the abdomen by 90° and workers of the two other bee subspecies by about 20° higher. Differences in those traits were highly significant between A. laboriosa and both A. dorsata subspecies, but were not significant between those two subspecies. The whole cycle of DBT was the most vigorous in A. d. breviligula (0.11 s), and it was twice as vigorous as in A. d. dorsata (0.26 s) and trice as in A. laboriosa (0.32 s). A. laboriosa twisted the body together with wings folded over the abdomen, while the two A. dorsata subspecies raised the abdomen between spread wings. This supports the opinion to treat A. laboriosa as a separate species.

After the drones are excited, they evert the endophallus, which mostly stops at partly everted stage with a slender tip at the end. The reason of the stop and the appearance of the tip is not known. There are transversal hairy folds at the ventral border of the cervix of honeybee drone endophallus. They form a duct inside the cervix. The dorsal walls of the duct come together at an acute angle and join at the summit quite tight. During partial eversion, the cervical duct appears at the end; however, its dorsal walls do not open (separate). The diameter of the duct is 0.4–0.5 mm. The bulb of the endophallus is not able to pass through such a small duct and therefore the eversion stops. Only after the pressure inside partly everted endophallus is increased sufficiently, the dorsal walls of the duct are opened, the interior of the cervix is enlarged and the bulb passes through it, which results in full eversion. The increased pressure inside the endophallus results in the semen being ejected with greater force. This is important during multiple matings of queen bees.

Philosophical implications of the current nanotechnology boom are not limited to possible problems in ethics. They result essentially from a new understanding of science, which is orientated toward applicability, and from an intensification of a technocratic view of nature in the context of visionary programs. For the integration of nanotechnological discovery in the great context of the history of science and ideas are Relations prepared to synthetic chemistry and to the paradigm of progress in modern times. The instrumental comprehension of nature, which show us the leading-ideas of nanotechnology, leads to the question as to which influence they could have on existing views of science and world. Possible answers to this question are outlined by a look at the ontological character of nano-objects, and by references to the one-sidedness of the view of nature, which is founded in the nanotechnological scenarios of the future.

A central question in behavioral ecology has been why animals live in groups. Previous theories about the evolution of sociality focused on the potential benefits of decreased risk of predation, increased foraging or feeding efficiency, and mutual aid in defending resources and/or rearing offspring. This paper argues that access to mutualistic endosymbiotic microbes is an underappreciated benefit of group living and sets out to reinvigorate Troyer’s hypothesis that the need to obtain cellulolytic microbes from conspecifics influenced the evolution of social behavior in herbivores and to extend it to nonherbivores. This extension is necessary because the benefits of endosymbionts are not limited to nutrition; endosymbionts also help protect their hosts from pathogens. When hosts must obtain endosymbionts from conspecifics, they are forced to interact. Thus, complex forms of sociality may be more likely to evolve when hosts must repeatedly obtain endosymbionts from conspecifics than when endosymbionts can be obtained either directly from the environment, are vertically transmitted, or when repeated inoculations are not necessary. Observations from a variety of taxa are consistent with the ideas that individuals benefit from group living by gaining access to endosymbionts and the complexity of social behavior is associated with the mode of acquisition of endosymbionts. Ways to test this theory include (a) experiments designed to examine the effects of endosymbionts on host fitness and how endosymbionts are obtained and (b) using phylogenetic analyses to examine endosymbiont–host coevolution with the goal of determining the relationship between the mode of endosymbiont acquisition and host sociality.

A major hindrance to studies of microbial diversity has been that the vast majority of microbes cannot be cultured in the laboratory and thus are not amenable to traditional methods of characterization. Environmental shotgun sequencing (ESS) overcomes this hurdle by sequencing the DNA from the organisms present in a microbial community. The interpretation of this metagenomic data can be greatly facilitated by associating every sequence read with its source organism. We report the development of CompostBin, a DNA composition-based algorithm for analyzing metagenomic sequence reads and distributing them into taxon-specific bins. Unlike previous methods that seek to bin assembled contigs and often require training on known reference genomes, CompostBin has the ability to accurately bin raw sequence reads without need for assembly or training. CompostBin uses a novel weighted PCA algorithm to project the high dimensional DNA composition data into an informative lower-dimensional space, and then uses the normalized cut clustering algorithm on this filtered data set to classify sequences into taxon-specific bins. We demonstrate the algorithm’s accuracy on a variety of low to medium complexity data sets.

We investigate a new model of tumor growth in which cell motility is considered an explicitly separate process from growth. Bulk tumor expansion is modeled by individual cell motility in a density-dependent diffusion process. This model is implemented in the context of an in vivo system, the tumor cord. We investigate numerically microscale density distributions of different cell classes and macroscale whole tumor growth rates as functions of the strength of transitions between classes. Our results indicate that the total tumor growth follows a classical von Bertalanffy growth profile, as many in vivo tumors are observed to do. This provides a quick validation for the model hypotheses. The microscale and macroscale properties are both sensitive to fluctuations in the transition parameters, and grossly adopt one of two phenotypic profiles based on their parameter regime. We analyze these profiles and use the observations to classify parameter regimes by their phenotypes. This classification yields a novel hypothesis for the early evolutionary selection of the metastatic phenotype by selecting against less motile cells which grow to higher densities and may therefore induce local collapse of the vascular network.

In social Hymenoptera, within-colony relatedness is usually high due to the haplodiploid sex-determining system. However, factors such as the presence of multiple reproductive queens (polygyny), multiple queen matings (polyandry) or worker reproduction result in decreased relatedness among workers and the brood they rear, and consequently dilute their inclusive fitness benefits from helping. Here, we investigated population genetic structure, mating system, worker reproduction and parthenogenesis in the desert ant Cataglyphis sabulosa. Analysis of worker genotypes showed that colonies are headed by a single queen, mated with 1–5 males. The inbreeding coefficient within colonies and the levels of relatedness between the queens and their mates were positive, indicating that mating occurs between related individuals. Moreover, the mates of a queen are on average related and contribute equally to worker production. Our analyses also indicate that colonies are genetically differentiated and form a population exhibiting no isolation-by-distance pattern, consistent with the independent foundation of new colonies (that is, without the help of workers). Finally, both ovarian dissections and genetic data on the parentage of males show that workers do not reproduce in queenright colonies; however, they lay both haploid (arrhenotokous males) and diploid (thelytokous females) eggs in queenless colonies. In contrast to the congeneric species C. cursor, where new queens are produced by thelytokous parthenogenesis, female sexuals of C. sabulosa result from classical sexual reproduction.

Honey bees (Apis mellifera) are eusocial insects that exhibit striking caste-specific differences in longevity. Queen honey bees live on average 1–2 years whereas workers live on average 15–38 days in the summer and 150–200 days in the winter. Previous studies of senescence in the honey bee have focused on establishing the importance of extrinsic mortality factors (predation, weather) and behavior (nursing and foraging) in worker bee longevity. However, few studies have tried to elucidate the mechanisms that allow queen honey bees to achieve their long lifespan without sacrificing fecundity. Here, we review both types of studies and emphasize the importance of understanding both proximate and ultimate causes of the unusual life history of honey bee queens.

We studied nest site selection by swarms of the red dwarf honeybee, Apis florea. By video recording and decoding all dances of four swarms, we were able to determine the direction and distances indicated by 1,239 dances performed by the bees. The bees also performed a total of 715 nondirectional dances; dances that were so brief that no directional information could be extracted. Even though dances converged over time to a smaller number of areas, in none of the swarms did dances converge to one site. As a result, even prior to lift off, bees performed dances indicating nest sites in several different directions. Two of four swarms traveled directly in what seemed to be the general direction indicated by the majority of dances in the half hour prior to swarm lift off. The other two traveled along circuitous routes in the general direction indicated by the dances. We suggest that nest site selection in A. florea has similar elements to nest site selection in the better-studied Apis mellifera. However, the observation that many more locations are indicated by dances prior to lift off also shows that there are fundamental differences between the two species.