IMPROVING GLOBAL HEALTH: COUNTING REASONS WHY

This paper examines cumulative ethical and self-interested reasons why wealthy developed nations should be motivated to do more to improve health care in developing countries. Egalitarian and human rights reasons why wealthy nations should do more to improve global health are that doing so would (1) promote equality of opportunity, (2) improve the situation of the worst-off, (3) promote respect of the human right to have one's most basic needs met, and (4) reduce undeserved inequalities in well-being. Utilitarian reasons for improving global health are that this would (5) promote the greater good of humankind, and (6) achieve enormous benefits while requiring only small sacrifices. Libertarian reasons are that this would (7) amend historical injustices and (8) meet the obligation to amend injustices that developed world countries have contributed to. Self-interested reasons why wealthy nations should do more to improve global health are that doing so would (9) reduce the threat of infectious diseases to developed countries, (10) promote developed countries' economic interests, and (11) promote global security. All of these reasons count, and together they add up to make an overwhelmingly powerful case for change. Those opposed to wealthy government funding of developing world health improvement would most likely appeal, implicitly or explicitly, to the idea that coercive taxation for redistributive purposes would violate the right of an individual to keep his hard-earned income. The idea that this reason not to improve global health should outweigh the combination of rights and values embodied in the eleven reasons enumerated above, however, is implausibly extreme, morally repugnant and perhaps imprudent.     

WHY SOME ADULTS DO NOT DRINK MILK

About three-fourths of all adult patients not drinking milk either do not like it (48 per cent), think it disagrees with them (13 per cent), or have no reason for not drinking it (16 per cent). However, most of the patients in all groups began to drink milk when given suitable information on its importance in diet.     

WHY DO BALEEN WHALES MIGRATE?1

The annual migrations of baleen whales are a conspicuous but unexplained feature of their behavioral repertoire. Some hypotheses offered to explain whale migration focus on direct benefits to the calf (thermoregulation, calm water) and some do not (resource tracking, and the “evolutionary holdover” hypothesis). Here, we suggest that a major selective advantage to migrating pregnant female baleen whales is a reduced risk of killer whale (Orcinus orca) predation on their newborn calves in low-latitude waters. Killer whale abundance in high latitudes is substantially greater than that in lower latitudes, and most killer whales do not appear to migrate with baleen whales. We suggest that the distribution of killer whales is determined more by their primary marine mammal prey, pinnipeds, and that following the baleen whale migrations would remove them from their pinniped prey. There are problems with all current hypotheses, most of which stem from a lack of directed research. We explore variation in migratory habits between species, populations, and individuals that may provide a “natural laboratory” for discriminating among the competing hypotheses.     

WHY EPISTASIS IS IMPORTANT FOR SELECTION AND ADAPTATION

Organisms are built from thousands of genes that interact in complex ways. Still, the mathematical theory of evolution is dominated by a gene‐by‐gene perspective in which genes are assumed to have the same effects regardless of genetic background. Gene interaction, or epistasis, plays a role in some theoretical developments such as the evolution of recombination, reproductive isolation, and canalization, but is strikingly missing from our standard accounts of phenotypic adaptation. This absence is most puzzling within the field of quantitative genetics, which, despite its polygenic perspective and elaborate statistical representation of epistasis, has not found a single important role for gene interaction in evolution. To the contrary, there is a widespread consensus that epistasis is evolutionary inert, and that all we need to know to predict evolutionary dynamics is the additive component of the genetic variance. This view may have roots in convenience, but also in theoretical results showing that the response to selection derived from epistatic variance components is not permanent and will decay when selection is relaxed. I show that these results are tied to a conceptual confusion, and are misleading as general statements about the significance of epistasis for the selection response and adaptation.     

WHY COMPENSATING WILDLIFE DAMAGES MAY BE BAD FOR CONSERVATION

Abstract: In an effort to attenuate human-wildlife conflict and promote conservation of charismatic megafauna, compensation programs for wildlife damages have been implemented in many countries. Compensating pastoralists and farmers for damage caused by wildlife reduces hunting pressure on wild animal populations. However, it can also lead to a decrease in efforts to prevent damage and exacerbate conflicts with wildlife. Furthermore, compensation programs increase the return to agriculture and can therefore be viewed as a subsidy toward crop and livestock production. Such subsidies can trigger agricultural expansion (and habitat conversion), an inflow of agriculture producers, and intensification of agricultural production. Each of these impacts is shown to have potentially adverse effects on the wildlife population that compensation intends to favor. In some circumstances, the net effect on the wildlife stock could be negative. This calls for a careful assessment of local ecological and economic conditions before compensation is implemented. Incentive mechanisms that are directly tied to conservation outcomes (e.g., payments to locals based on the size of the wildlife population) should be considered instead of compensation programs.     

WHY WE ARE NOT DEAD ONE HUNDRED TIMES OVER

The possibility of pervasive weak selection at tens or hundreds of millions of sites across the genome, suggested by recent studies of silent site DNA sequence variation and divergence, raises the problem of the survival of the population in the face of the large genetic load that may result. Two alternative resolutions of this problem are presented for populations where recombination is sufficiently frequent that different sites under selection evolve independently. One invokes weak stabilizing selection, of the magnitude compatible with abundant silent site variability. This can be shown to produce only a modest genetic load, due to the effectiveness of even weak stabilizing selection in keeping the trait mean close to the optimum. The other invokes soft selection, whereby individuals compete for a limiting resource whose abundance determines the absolute fitness of the population. Weak purifying selection at a large number of sites produces only a small variance in fitness among individuals within the population, due to the fact that most sites are fixed rather than polymorphic. Even when it produces a large genetic load, it is compatible with the observations on fitness variance when selection is soft. It may be very difficult to distinguish between these two possibilities.