American Scientist

This roundup summarizes some notable recent items about scientific research, selected from news reports compiled in Sigma Xi’s free electronic newsletter.

Monkey on the Menu

Each week, travelers smuggle more than five tons of illegal African bushmeat through Paris’s largest airport. That estimate troubles conservation biologists, who usually think of trade in wild animal meat as a local, not international, issue. But a systematic search of 134 airline passengers arriving from west and central Africa revealed that 7 percent of them were toting illegal bushmeat such as monkeys and pangolins. The meat was likely destined for an underground luxury market where it could bring more than $15 per pound. Stricter law enforcement may be necessary, the authors argue, to prevent the spread of disease and the impact on protected species.

Chaber, A.-L., et al. The scale of illegal meat importation from Africa to Europe via Paris. Conservation Letters (published online June 7)

Of Texas and Mars

Rarely do geologists see a canyon form in real time. But in 2002, a catastrophic Texas deluge carved out a gorge more than 30 feet deep and over a mile long in just three days. Based on aerial photos, gorge morphology, and flow measurements from the flood, researchers conclude that the new canyon grew quickly because the torrent ripped out entire boulders of blocky limestone, rather than gradually abrading the rock. The unusual opportunity to connect known water-flow rates to canyon geology could help reconstruct even bigger prehistoric megafloods that shaped parts of Earth and Mars.

Lamb, M. P., and M. A. Fonstad. Rapid formation of a modern bedrock canyon by a single flood event. Nature Geoscience 3:477–481 (July)

Kids Thrive with Two Moms

Same-sex couples are raising hundreds of thousands of children in the United States. And, according to a long-term study, those kids are competent and well-adjusted. The study followed about 80 children conceived by lesbian moms using donor insemination in the mid 1980s. By the age of 17, the kids rated better in academic and social competence and had fewer behavior problems than a nationally representative sample. The comparison isn’t perfect—the two samples of children were matched for age and socioeconomic status, but not ethnicity or region—but the results nevertheless suggest that kids with two moms are doing fine.

Gartrell, N., and H. Bos. U.S. National Longitudinal Lesbian Family Study: Psychological adjustment of 17-year-old adolescents. Pediatrics 126:28–36 (July)

Organic Ecology

An organic potato field can take pretty good care of itself. That’s because it fosters a well-balanced community of pathogens and predatory insects that restrain the voracious Colorado potato beetle (Leptinotarsa decemlineata). Conventional fields have just as many beneficial species, but their abundance is skewed such that a single species can make up 80 percent of the population. Ecologists assembled 42 experimental mini–potato fields, and found that evenly distributed predator and pathogen communities typical of organic fields resulted in 18 percent fewer potato beetles and 35 percent larger plants than did skewed communities. The results highlight the importance of species evenness—an often-neglected aspect of biodiversity.

Crowder, D. W., et al. Organic agriculture promotes evenness and natural pest control. Nature 466:109–112 (July 1)

Beyond “Ribbit”

There’s more than one way to pick a fight. Male red-eyed treefrogs (Agalychnis callidryas) defend territories with vocal calls and rapid hind-leg push-ups—but it wasn’t clear whether other frogs respond to the sight of a bouncing male, or to the vibrations he makes. Researchers decoupled the two signals by mounting a robotic bouncing frog near a sapling, and using a mechanical shaker to agitate the plant. Either signal by itself incited aggression in about half the frogs tested—suggesting that vibrations alone put a frog on alert. Although vibrational signals are well known in insects and terrestrial animals, few studies have examined their importance in other arboreal creatures.

Caldwell, M. S., et al. Vibrational signaling in the agonistic interactions of red-eyed treefrogs. Current Biology 20:1010–1017 (June 8)

Biblical Bee-Traders

Archaeologists have unearthed the 3,000-year-old remains of honeybees (Apis mellifera) inside clay hives in northern Israel. The ancient insects don’t match the local subspecies, suggesting that beekeepers imported their stock from hundreds of miles away. Among the fragmented bee parts, one leg and a couple of wings were intact enough to identify the subspecies. Based on their physical proportions, the appendages probably came from A. mellifera anatoliaca, which today lives in cool, moist climates of Turkey. Importing these hives was probably worth the trouble: The Anatolian subspecies is more docile and produces more honey than Israel’s native honeybees.

Bloch, G., et al. Industrial apiculture in the Jordan valley during Biblical times with Anatolian honeybees. Proceedings of the National Academy of Sciences of the U.S.A. 107:11240–11244 (June 22)

Not Junk After All

Pseudogenes, once dismissed as inert and defective copies of functional genes, actually execute a previously unknown kind of gene regulation. At least that’s the case for the tumor-suppressor gene PTEN. PTEN is transcribed to mRNA that codes for a protein. Whether a cell will actually build that protein, however, depends on whether the mRNA survives or is tagged for destruction by microRNAs. And that’s where the pseudogene comes in. Its mRNA is so similar to PTEN’s that it serves as a decoy, diverting destructive microRNAs and leaving PTEN free to carry out its anti-cancer function. Several gene-expression experiments in cell culture back this model for PTEN and its pseudogene; now researchers wonder whether other seemingly derelict sequences are equally useful.

Poliseno, L., et al. A coding-independent function of gene and pseudogene mRNAs regulates tumour biology. Nature 465:1033–1038 (June 24)