Humans are thought to be unique in their ability to help others voluntarily even though it may sometimes incur substantial costs. However, there are a growing number of studies showing that prosocial behaviors can be observed, not only in humans, but also among nonhuman primates that live in complex social groups. Prosociality has often been described as a major factor that facilitates group living. Nonetheless, it has seldom been explored whether solitary living primates, such as orangutans, share this propensity. In the present study, we tested four captive orangutans (Pongo abelii × pigmaeus, Pongo pigmaeus) in a simple food-delivering task. They had a choice, incurring the same cost, between getting a food reward for themselves and providing an additional food reward to a conspecific recipient passively sitting in an adjacent booth. Two orangutans played the actor's role, and two orangutans participated as recipients. The results showed that the actors did not choose to deliver food to the recipients more often than expected by chance (51.3 % on average). The control condition demonstrated that this tendency was independent of the actor's understanding of the task. These findings suggest that orangutans do not spontaneously share benefits with other conspecifics, even when the prosocial choice does not disadvantage them. This study gives the first experimental evidence that socially housed captive orangutans do not behave prosocially in a choice paradigm experiment. Further studies using a different experimental paradigm should be conducted to examine whether this tendency is consistent with previous findings hypothesizing that the enhanced prosocial propensity shown in humans and other group living primates is an evolutionary outcome of living in complex social environments.
Division of labor, an adaptation in which individuals specialize in performing tasks necessary to the colony, such as nest defense and foraging, is believed key to eusocial insects' remarkable ecological success. Here we report, for the first time, a completely novel specialization in a eusocial insect, namely the ability of Cataglyphis cursor ants to rescue a trapped nestmate using precisely targeted behavior. Labeled “precision rescue”, this behavior involves the ability of rescuers not only to detect what, exactly, holds the victim in place, but also to direct specific actions to this obstacle. Individual ants, sampled from each of C. cursor's three castes, namely foragers, nurses and inactives, were experimentally ensnared (the “victim”) and exposed to a caste-specific group of potential “rescuers.” The data reveal that foragers were able to administer, and obtain, the most help while members of the youngest, inactive caste not only failed to respond to victims, but also received virtually no help from potential rescuers, regardless of caste. Nurses performed intermediate levels of aid, mirroring their intermediate caste status. Our results demonstrate that division of labor, which controls foraging, defense and brood care in C. cursor, also regulates a newly discovered behavior in this species, namely a sophisticated form of rescue, a highly adaptive specialization that is finely tuned to a caste member's probability of becoming, or encountering, a victim in need of rescue.
The RUBICODE project draws on expertise from a range of disciplines to develop and integrate frameworks for assessing the impacts of environmental change on ecosystem service provision, and for rationalising biodiversity conservation in that light. With such diverse expertise and concepts involved, interested parties will not be familiar with all the key terminology. This paper defines the terms as used within the project and, where useful, discusses some reasoning behind the definitions. Terms are grouped by concept rather than being listed alphabetically.
Most apple cultivars are self-sterile and completely dependent on cross-pollination from a different
cultivar in order to set fruit. Various insects may be pollinators, but the main one is the honey bee [HB]
(Apis mellifera). However, despite the advantages of the honey bee as pollinator of many plants, it is a
relatively inefficient pollinator of apple flowers. The main reason for this is the tendency of HBs to visitthe
appleflower fromthe side (sideworker),thus “stealing”nectar withouttouching theflower’s reproductive
organs – stamens and stigma. In contrast, a bee that visits the flower from the top (topworker) contacts
the flower’s reproductive organs, which results in better pollination. Due to the low pollination efficiency,
few seeds are formed, and often the resulting fruit is too small to be of commercial value. Experiments
conducted in Israel over the last few years have shown for the first time that adding bumblebees [BB]
(Bombus terrestris) into pear orchards improved cross-pollination, thus increasing the number of seeds
and subsequently fruit size. The goal of the present work was to test the hypothesis that adding BBs
to apple orchards may improve cross-pollination. We found that adding BBs to the HBs in the apple
orchard improved pollination in all tested cultivars, especially in ‘Gala’, which naturally suffers from
relatively few seeds in the fruit. It appears that the addition of BBs did not only increase the number of
pollinating insects in the orchard that could perform cross-pollination, including in the cool mornings and
in adverse weather conditions, but that it also changed HB foraging behavior, which resulted in improved
cross-pollination and increased efficiency, and subsequently more seeds and larger fruit. The improved
pollination was due to the greater mobility of HBs between rows of pollinated cultivar and pollenizer,
and to the greater proportion of topworkers, which are more efficient pollinators.
We propose that the Anthropocene be defined as the last c. 2000 years of the late Holocene and characterized on the basis of anthropogenic soils. This contrasts with the original definition of the Anthropocene as the last c. 250 years (since the Industrial Revolution) and more recent proposals that the Anthropocene began some 5000 to 8000 years ago in the early to mid Holocene (the early-Anthropocene hypothesis). Anthropogenic soil horizons, of which several types are recognized, provide extensive terrestrial stratigraphic markers for defining the start of the Anthropocene. The pedosphere is regarded as the best indicator of the rise to dominance of human impacts on the total environment because it reflects strongly the growing impact of early
civilisations over much of the Earth’s surface. Hence, the composition of anthropogenic soils is deemed more appropriate than atmospheric composition in providing ‘golden spikes’ for the Anthropocene.
In the nineteenth century, “virus” commonly meant an agent (usually unknown) that caused disease in inoculation experiments. By the 1890s, however, some disease-causing agents were found to pass through filters that retained the common bacteria. Such an agent was called “filterable virus,” the best known being the virus that caused tobacco mosaic disease. By the 1920s there were many examples of filterable viruses, but no clear understanding of their nature. However, by the 1930s, the term “filterable virus” was being abandoned in favor of simply “virus,” meaning an agent other than bacteria. Visualization of viruses by the electron microscope in the late 1930s finally settled their particulate nature. This article describes the ever-changing concept of “virus” and how virologists talked about viruses. These changes reflected their invention and reinvention of the concept of a virus as it was revised in light of new knowledge, new scientific values and interests, and new hegemonic technologies.
Are viruses more biologically successful than cellular life? Here we examine many ways of gauging biological success, including numerical abundance, environmental tolerance, type biodiversity, reproductive potential, and widespread impact on other organisms. We especially focus on successful ability to evolutionarily adapt in the face of environmental change. Viruses are often challenged by dynamic environments, such as host immune function and evolved resistance as well as abiotic fluctuations in temperature, moisture, and other stressors that reduce virion stability. Despite these challenges, our experimental evolution studies show that viruses can often readily adapt, and novel virus emergence in humans and other hosts is increasingly problematic. We additionally consider whether viruses are advantaged in evolvability—the capacity to evolve—and in avoidance of extinction. On the basis of these different ways of gauging biological success, we conclude that viruses are the most successful inhabitants of the biosphere.
Viruses are by far the most abundant 'lifeforms' in the oceans and are the reservoir of most of the genetic diversity in the sea. The estimated 1030 viruses in the ocean, if stretched end to end, would span farther than the nearest 60 galaxies. Every second, approximately 1023 viral infections occur in the ocean. These infections are a major source of mortality, and cause disease in a range of organisms, from shrimp to whales. As a result, viruses influence the composition of marine communities and are a major force behind biogeochemical cycles. Each infection has the potential to introduce new genetic information into an organism or progeny virus, thereby driving the evolution of both host and viral assemblages. Probing this vast reservoir of genetic and biological diversity continues to yield exciting discoveries.