Resurrected Plants and Sexy-scented Fruit Flies

• Burmese Pythons, which are devastating the Southern Florida/Everglades ecosystem, average about 20 feet in length. Raccoons, opossums, rabbits, and bobcats are disappearing as the population of pythons continues to soar. Florida has faced many ecological challenges over the years, but this one will require a tremendous investment in money and manpower to overcome. (www.msnbc.msn.com; many other sources)

• Russian scientists resurrected a frozen plant (Silene stenophylla) that had lived in Siberia 32,000 years ago and was buried beneath 40 feet of ice. They took tissue from the immature seeds of the plant and managed to get the tissue to grow into mature seeds, which they planted in normal soil. The seeds grew up into a fully formed plant, flowered, and formed viable seeds. This discovery lends credence to the suggestion by Australian scientist James Haile that the permafrost may be a “giant molecular freezer” that preserves the DNA of thriving Pleistocene ecosystems. Can a mammoth be far behind? (Yashina et al, 2012, Proc. of the National Acad. of Sciences, Feb. 21; http://www.news.blogs.cnn.com)

• Marijuana is the most widely used illicit substance in the world; 43 percent of U.S. adults aged 18 and older have tried the drug at least once. Marijuana has a few legitimate medical uses (e.g., to treat glaucoma, reduce nausea from cancer drugs, etc.), but do recreational marijuana users become addicted to the drug? Researchers asked over 8,000 people between the ages of 16 and 64 about their use of this and other drugs. Only about 9 percent fit a diagnosis of marijuana dependence, but there are often serious side effects. Heavy usage can lead to intolerance to the drug and withdrawal symptoms when trying to stop, and such users can end up with respiratory and cardiovascular problems. Short-term memory may also be affected. And some users do become addicted. Among those “successfully” treated by psychotherapists, 60 percent relapsed within six months. Scientists are learning that the chemicals to which we are exposed can induce changes in our genes (epigenetics). This raises the possibility that long-term marijuana use may permanently alter genes that control a person’s mental state. (Scientific American Mind, Mar./April, 2012; other sources)

• A pheromone is a volatile chemical released from one animal that brings about a change in behavior of another member of the species. In fruit flies, the composition of a certain pheromone released from the body surface of males and females changes as the flies age. Older fruit flies are less attractive to other flies because the amount of their “attractiveness” pheromone diminishes. Figuratively, they don’t smell sexy. However, when scientists isolated the pheromone from young flies and applied it to older ones, they once more became attractive sex partners. Such findings raise many questions about the role of pheromones in animal behavior. (Pletcher et al, 2012, J. Exp. Biology, Feb. 9)

• The phrase “a plaque of locusts” was frighteningly illustrated in 1874, when after several years of drought locusts went on a rampage in the Midwest. “[A cloud of locusts] passed over Lincoln, Nebraska, from 9:00 AM to 3:00 PM in an unbroken column estimated to be at least 300 miles wide from east to west and averaging at least a half mile in depth. When that cloud came to earth, the results were disastrous.” They reduced fields of ripe grain to stalks and even ate the brim off a farmer’s straw hat. (Charles Howes, 1984, This Place Called Kansas)