Conventional wisdom has long held that tropical rainforests act as a sink for carbon dioxide, cleansing the atmosphere of a major greenhouse gas. However, biologists studying the forests of Costa Rica are finding that rising temperatures are causing trees to grow less and to pump out more carbon dioxide, adding to an accelerating pattern of global warming.

Phenotypic selection occurs when individuals with certain characteristics produce more surviving offspring than individuals with other characteristics. Although selection is regarded as the chief engine of evolutionary change, scientists have only recently begun to measure its action in the wild. These studies raise numerous questions: How strong is selection, and do different types of traits experience different patterns of selection? Is selection on traits that affect mating success as strong as selection on traits that affect survival? Does selection tend to favor larger body size, and, if so, what are its consequences? We explore these questions and discuss the pitfalls and future prospects of measuring selection in natural populations.

The conservation and sustainable use of marine resources is a highlighted goal on a growing number of national and international policy agendas. Unfortunately, efforts to assess progress, as well as to strategically plan and prioritize new marine conservation measures, have been hampered by the lack of a detailed, comprehensive biogeographic system to classify the oceans. Here we report on a new global system for coastal and shelf areas: the Marine Ecoregions of the World, or MEOW, a nested system of 12 realms, 62 provinces, and 232 ecoregions. This system provides considerably better spatial resolution than earlier global systems, yet it preserves many common elements and can be cross-referenced to many regional biogeographic classifications. The designation of terrestrial ecoregions has revolutionized priority setting and planning for terrestrial conservation; we anticipate similar benefits from the use of a coherent and credible marine system.

Evolutionary biology is a historical science, like astronomy and geology. Understanding how and why evolution has occurred requires synthesizing multiple lines of inquiry. Historical studies, such as those that estimate phylogenetic trees, can detail the pattern of evolutionary diversification, whereas studies on living species can provide insight into the processes that affect ecological interactions and evolutionary change. The evolutionary radiation of Anolis lizards in the Greater Antilles illustrates the interplay between historical and modern-day approaches and strongly supports the hypothesis that interspecific interactions drive adaptive diversification. Studies of these species also demonstrate the role that manipulative experiments can play in understanding evolutionary phenomena.

Coral reefs worldwide are being degraded by human-induced disturbances, resulting in ecological, economic, and cultural losses. Runoff and sedimentation are among the greatest threats to the coastal reefs surrounding high islands and adjacent to continental landmasses. Existing scientific data identify the key stressors, synergisms, and outcomes at the coral reef ecosystem, community, and population levels. These data demonstrate that marine protected areas alone may be insufficient for coral reef protection; integrated watershed management practices are also needed. Gaps in the effectiveness of environmental policy, legislation, and regulatory enforcement have resulted in the continued degradation of US and Australian reefs. Several Pacific islands, with intact resource stewardship and traditional leadership systems, have been able to apply research findings to coral reef management policies relatively quickly. Three case histories in Micronesia provide insight into how social sciences and biophysical data can be combined to manage human behaviors responsible for coral reef destruction.

The method of multiple working hypotheses, developed by the 19th-century geologist T. C. Chamberlin, is an important philosophical contribution to the domain of hypothesis construction in science. Indeed, the concept is particularly pertinent to recent debate over the relative merits of two different statistical paradigms: null hypothesis testing and model selection. The theoretical foundations of model selection are often poorly understood by practitioners of null hypothesis testing, and even many proponents of Chamberlin's method may not fully appreciate its historical basis. We contend that the core of Chamberlin's message, communicated over a century ago, has often been forgotten or misrepresented. Therefore, we revisit his ideas in light of modern developments. The original source has great value to contemporary ecology and many related disciplines, communicating thoughtful consideration of both complexity and causality and providing hard-earned wisdom applicable to this new age of uncertainty.

Whether crocodiles shed tears while eating has been fodder for fable and controversy for hundreds of years. We present the first unequivocal evidence that crocodilians lacrimate during meals and that they do so in a peculiar fashion.

Open-access journals are growing in number and importance. Because they rely on revenue from publication fees rather than subscriptions, these journals have important economic implications for the institutions that sponsor, produce, and use research in the life sciences. This article shows how the wholesale adoption of open-access pricing would influence institutional journal costs in the field of cell biology. Estimating prices under two open-access models, we find that a switch to open access would result in substantial cost reductions for most institutions. At the same time, the top universities would pay up to 10 times as much as they currently do. Institutions with fewer than 4.29 million library volumes would be likely to save money under either open-access model. The long-term viability of open-access publishing in the biosciences may depend on the establishment of an environment in which the top research institutions are willing and able to pay a greater share of the total systemwide cost.