Not only are beetles among the most diverse group of animals on Earth, but some rival the most flamboyant birds and dazzling coral reef fish with their metallic sheens. Researchers have now traced the evolutionary history of this iridescence in one group of beetles, the weevils, and identified an unexpectedly varied assortment of complex light-altering crystals in the insects. The new work also shows that these diverse crystal architectures all share a single origin in these beetles' evolutionary past. Weevils "have developed high crystal diversity from a relatively modest tool kit," says Ainsley Seago, a systematist with the Australian National Insect Collection in Canberra, who led the work.
Isabel López-Rull and her colleagues at the National
Autonomous University of Mexico in Mexico City found that nests of house
sparrows (Passer domesticus) and house finches (Carpodacus mexicanus;
pictured) with higher levels of cellulose acetate, a component of
cigarette butts, had fewer mites. The researchers attached fibres from
either smoked or unsmoked cigarette filters to parasite-attracting heat
traps and placed them in 27 sparrow and 28 finch nests. Traps bearing
fibres from smoked filters, which contain more nicotine than those of
unsmoked ones, captured fewer mites, suggesting that nicotine — and
perhaps other compounds in cigarettes — repel the parasites.
Birds have long been known to line their nests with vegetation
that deters parasites, and the authors suggest that the use of cigarette
butts is an urbanized form of this earlier adaptation.
Biol. Lett. http://dx.doi.org/10.1098/rsbl.2012.0931 (2012)
Research Highlights Nature 492, 156 (13 December 2012)

















+posited+that+life+emerged+from+compounds+in+the+atmosphere+of+early+Earth.jpg)
