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<jats:p> The physical processes causing energy exchange between the Sun’s hot corona and its cool lower atmosphere remain poorly understood. The chromosphere and transition region (TR) form an interface region between the surface and the corona that is highly sensitive to the coronal heating mechanism. High-resolution observations with the Interface Region Imaging Spectrograph (IRIS) reveal rapid variability (~20 to 60 seconds) of intensity and velocity on small spatial scales (≲500 kilometers) at the footpoints of hot and dynamic coronal loops. The observations are consistent with numerical simulations of heating by beams of nonthermal electrons, which are generated in small impulsive (≲30 seconds) heating events called “coronal nanoflares.” The accelerated electrons deposit a sizable fraction of their energy (≲10 <jats:sup>25</jats:sup> erg) in the chromosphere and TR. Our analysis provides tight constraints on the properties of such electron beams and new diagnostics for their presence in the nonflaring corona. </jats:p>

<jats:sec> <jats:title>BACKGROUND</jats:title> <jats:p>Differences among species in their ability to adapt to environmental change threaten biodiversity, human health, food security, and natural resource availability. Pathogens, pests, and cancers often quickly evolve resistance to control measures, whereas crops, livestock, wild species, and human beings often do not adapt fast enough to cope with climate change, habitat loss, toxicants, and lifestyle change. To address these challenges, practices based on evolutionary biology can promote sustainable outcomes via strategic manipulation of genetic, developmental, and environmental factors. Successful strategies effectively slow unwanted evolution and reduce fitness in costly species or improve performance of valued organisms by reducing phenotype-environment mismatch or increasing group productivity. Tactics of applied evolutionary biology range broadly, from common policies that promote public health or preserve habitat for threatened species—but are easily overlooked as having an evolutionary rationale, to the engineering of new genomes.</jats:p> </jats:sec> <jats:sec> <jats:title>ADVANCES</jats:title> <jats:p>The scope and development of current tactics vary widely. In particular, genetic engineering attracts much attention (and controversy) but now is used mainly for traits under simple genetic control. Human gene therapy, which mainly involves more complex controls, has yet to be applied successfully at large scales. In contrast, other methods to alter complex traits are improving. These include artificial selection for drought- and flood-tolerant crops through bioinformatics and application of “life course” approaches in medicine to reduce human metabolic disorders.</jats:p> <jats:p>Successful control of unwanted evolution depends on governance initiatives that address challenges arising from both natural and social factors. Principal among these challenges are (i) global transfer of genes and selection agents; (ii) interlinked evolution across traditional sectors of society (environment, food, and health); and (iii) conflicts between individual and group incentives that threaten regulation of antibiotic use and crop refuges. Evolutionarily informed practices are a newer prospect in some fields and require more systematic research, as well as ethical consideration—for example, in attempts to protect wild species through assisted migration, in the choice of source populations for restoration, or in genetic engineering.</jats:p> </jats:sec> <jats:sec> <jats:title>OUTLOOK</jats:title> <jats:p>A more unified platform will better convey the value of evolutionary methods to the public, scientists, and decision-makers. For researchers and practitioners, applications may be expanded to other disciplines, such as in the transfer of refuge strategies that slow resistance evolution in agriculture to slow unwanted evolution elsewhere (for example, cancer resistance or harvest-induced evolution). For policy-makers, adoption of practices that minimize unwanted evolution and reduce phenotype-environment mismatch in valued species is likely essential to achieve the forthcoming Sustainable Development Goals and the 2020 Aichi Biodiversity Targets.</jats:p> </jats:sec>

<jats:p>The heating of the outer solar atmospheric layers, i.e., the transition region and corona, to high temperatures is a long-standing problem in solar (and stellar) physics. Solutions have been hampered by an incomplete understanding of the magnetically controlled structure of these regions. The high spatial and temporal resolution observations with the Interface Region Imaging Spectrograph (IRIS) at the solar limb reveal a plethora of short, low-lying loops or loop segments at transition-region temperatures that vary rapidly, on the time scales of minutes. We argue that the existence of these loops solves a long-standing observational mystery. At the same time, based on comparison with numerical models, this detection sheds light on a critical piece of the coronal heating puzzle.</jats:p>

<jats:p>The solar chromosphere and transition region (TR) form an interface between the Sun’s surface and its hot outer atmosphere. There, most of the nonthermal energy that powers the solar atmosphere is transformed into heat, although the detailed mechanism remains elusive. High-resolution (0.33–arc second) observations with NASA’s Interface Region Imaging Spectrograph (IRIS) reveal a chromosphere and TR that are replete with twist or torsional motions on sub–arc second scales, occurring in active regions, quiet Sun regions, and coronal holes alike. We coordinated observations with the Swedish 1-meter Solar Telescope (SST) to quantify these twisting motions and their association with rapid heating to at least TR temperatures. This view of the interface region provides insight into what heats the low solar atmosphere.</jats:p>

<jats:sec> <jats:title>Background</jats:title> <jats:p>The human sense of fairness presents an evolutionary puzzle because it appears to run counter to the short-term interests of at least some parties. We not only react negatively to getting less than a partner but sometimes also to getting more, which seems illogical. Following an ideal of impartiality, we seek appropriate outcomes for everyone within the community, not just a few individuals, and, in particular, not just ourselves. Why do we react this way? Are we the only species to do so? Here, we consider the evidence with regard to nonhuman primates and other animals to illuminate the evolution of the sense of fairness. Because social ideals escape measurement, we focus on behavioral responses to equal versus unequal reward division. Moreover, a true sense of fairness includes taking account of receiving both less than a partner and more than a partner. Therefore, we consider the evidence for both of these in other species and how this informs our understanding of the evolution of fairness in humans.</jats:p> </jats:sec> <jats:sec> <jats:title>Advances</jats:title> <jats:p>There is widespread evidence for sensitivity to receiving less than a partner, or “first-order inequity aversion” (IA), in species that cooperate outside mating bonds and kinship. In these studies, animals are paired with a social partner who receives a preferred reward for completing a task. Subjects may respond by refusing to participate or refusing to accept the food reward, and such reactions are compared with those following control tests in which both subjects receive the same reward for the same effort. Increased responses when the partner receives a preferred reward are indicative of a sensitivity to inequity.</jats:p> <jats:p>Thus far, passive and active protest against unfavorable outcomes has been documented in monkeys, apes, dogs, and birds. It is thought that these species compare their outcomes with those of others so as to judge the merit of their partnerships. They may turn away from partners that appropriate more than their fair share of the yields of cooperation.</jats:p> <jats:p>A complete sense of fairness also includes second-order IA, however, which seeks to equalize outcomes even at a short-term cost to the self. This requires individuals to give up an immediate benefit to stabilize a long-term valuable cooperative relationship. Second-order IA reactions have thus far been found only in humans and apes. We hypothesize that second-order IA requires anticipation of first-order IA in the partner and its negative impact on the relationship. To forestall these consequences, and ensure continued cooperation, outcomes are equalized between partners.</jats:p> </jats:sec> <jats:sec> <jats:title>Outlook</jats:title> <jats:p>Thus, humans and other species seem to share basic reactions to inequity, which serves to sustain cooperation. We postulate that the basic emotional reactions and calculations underlying our sense of fairness are rooted in our primate background and offer a model that places these reactions in the context of cooperative relationships.</jats:p> <jats:p>Future research should more explicitly investigate the key variables underlying IA, such as the degree of dependence on cooperation, anticipation of the way resource division affects relationships, and the freedom to choose among and change partners. A cross-species investigation with a standardized paradigm, including both first- and second-order IA, may further illuminate the factors involved and help verify or falsify the model proposed.</jats:p> </jats:sec>

<jats:p> As the interface between the Sun’s photosphere and corona, the chromosphere and transition region play a key role in the formation and acceleration of the solar wind. Observations from the Interface Region Imaging Spectrograph reveal the prevalence of intermittent small-scale jets with speeds of 80 to 250 kilometers per second from the narrow bright network lanes of this interface region. These jets have lifetimes of 20 to 80 seconds and widths of ≤300 kilometers. They originate from small-scale bright regions, often preceded by footpoint brightenings and accompanied by transverse waves with amplitudes of ~20 kilometers per second. Many jets reach temperatures of at least ~10 <jats:sup>5</jats:sup> kelvin and constitute an important element of the transition region structures. They are likely an intermittent but persistent source of mass and energy for the solar wind. </jats:p>

<jats:p>The solar atmosphere was traditionally represented with a simple one-dimensional model. Over the past few decades, this paradigm shifted for the chromosphere and corona that constitute the outer atmosphere, which is now considered a dynamic structured envelope. Recent observations by the Interface Region Imaging Spectrograph (IRIS) reveal that it is difficult to determine what is up and down, even in the cool 6000-kelvin photosphere just above the solar surface: This region hosts pockets of hot plasma transiently heated to almost 100,000 kelvin. The energy to heat and accelerate the plasma requires a considerable fraction of the energy from flares, the largest solar disruptions. These IRIS observations not only confirm that the photosphere is more complex than conventionally thought, but also provide insight into the energy conversion in the process of magnetic reconnection.</jats:p>

<jats:p> The 25th anniversary of the magnitude ( <jats:italic>M</jats:italic> ) 6.9 Loma Prieta earthquake that struck the San Francisco Bay Area on 17 October 1989 is a fitting time to examine what progress has been made in increasing community resilience to minimize seismic risk. The regions affected by the 2010 <jats:italic>M</jats:italic> 7.0 earthquake that struck Port-au-Prince, Haiti, and the <jats:italic>M</jats:italic> 8.8 event near Concepción, Chile, a few weeks later illustrate the extremes in earthquake resilience. In the zone of most intense shaking, 1 of every 10 Haitians was killed, compared to 1 of every 2500 Chileans, reflecting huge differences in construction quality and community resilience. The Loma Prieta event left 63 people dead, largely the result of the collapse of a bridge, an overpass, and homes built on unconsolidated fill. But beyond the loss of life, the Bay Area was affected by more than $10 billion in disruption of economic activity and damaged infrastructure. One challenge in implementing community resilience is to use science and engineering to find solutions that not only save lives but also get communities back to business as quickly as possible after a seismic event. </jats:p>