Friday, June 29, 2007

Last Issue of Science (June 2007)

In the post yesterday I said that normative theorists can benefit by exposing themselves to even just periodic updates on the empirical considerations that arise in the effort to mitigate different kinds of disadvantage. And the latest issue of Science contains a wealth of such information. Here is a sample of some of the highlights from that issue:

Democratic Congress Begins to Put Its Stamp on Science
Eli Kintisch

Six months into their rule on Capitol Hill, the Democrats have begun to make their mark on science policy. Many of their moves have underscored differences with the White House, including efforts to overturn the ban on federal funding for work on new embryonic stem lines, prominent accusations that the Bush Administration has politicized science advice, and proposals to increase and reshape funding for climate change research. But as far as the Administration's most prominent science initiative is concerned, the new Congress has so far been more than supportive, at least in loosening the purse strings: It is poised to top the president's generous requests for the multiagency American Competitiveness Initiative (ACI), which is aimed at sharply increasing funds for the physical sciences.

Relative Differences: The Myth of 1%
Jon Cohen

"For many, many years, the 1% difference served us well because it was underappreciated how similar we were," says Pascal Gagneux, a zoologist at UC San Diego. "Now it's totally clear that it's more a hindrance for understanding than a help."

Using novel yardsticks and the flood of sequence data now available for several species, researchers have uncovered a wide range of genomic features that may help explain why we walk upright and have bigger brains--and why chimps remain resistant to AIDS and rarely miscarry. Researchers are finding that on top of the 1% distinction, chunks of missing DNA, extra genes, altered connections in gene networks, and the very structure of chromosomes confound any quantification of "humanness" versus "chimpness." "There isn't one single way to express the genetic distance between two complicated living organisms," Gagneux adds.

A Reversal of Fortune in HIV-1 Integration
Alan Engelman

A customized enzyme that effectively excises integrated HIV-1 from infected cells in vitro might one day help to eradicate virus from AIDS patients.

A Narrow Road to Cooperation
Robert Boyd and Sarah Mathew

In every human society, from small-scale foraging bands to gigantic modern nation states, people cooperate with each other to solve collective-action problems. They share food to ensure against shortfalls, risk their lives in warfare to protect their group, work together in building canals and fortifications, and punish murderers and thieves to maintain social order. Because collective action benefits everyone in the group, whether or not they contribute, natural selection favors non-contributors. So, why do people contribute? Everyday experience suggests that people contribute to avoid being punished by others.

But this answer raises a second question: Why do people punish? From an evolutionary perspective, this question has two parts: First, how can contributors who punish avoid being replaced by "second-order" free-riders who contribute but do not incur the cost of punishing? There has been much work on this topic lately, and plausible solutions have emerged (1-5). However, these solutions are not much good unless we can solve the second problem: How can punishment become established within populations in the first place? On page 1905 of this issue, Hauert et al. provide the first cogent answer to this question (6). Surprisingly, they find that punishment can become established if there are individuals who neither produce collective benefits nor consume collective benefits produced by others.

Seeking Clarity in Hormones' Effects on the Heart
Jennifer Couzin

Women hitting menopause these days can be forgiven for feeling baffled about the risks of hormone replacement therapy (HRT). Several years ago, researchers announced that the Women's Health Initiative (WHI), two massive trials of more than 27,000 women, had shown HRT to be surprisingly unhelpful, even unsafe--in particular, a combination of estrogen and progestin appeared to cause heart attacks rather than prevent them, as expected. Hormone use plummeted.

But now new studies that break down WHI participants along age lines are suggesting that women in their 50s, those most likely to suffer menopause symptoms that can be helped by hormones, may not experience cardiac risks from the drugs after all--and might even benefit, depending on whether they received the combination or estrogen alone. Even among researchers who collaborate in the field, the findings remain both nuanced and contentious, with some disagreeing over how to interpret the data they collect. Researchers and the reporters who cover their work are struggling, too, in assessing the overall risk-benefit balance of HRT amid a stream of papers that examine individual risk factors in isolation.


UPDATE: There is also this story, which is also covered in The Guardian.