Snippets From Science

• In dragonflies and some other insects, when several males mate with one female, there occurs a phenomenon known as “sperm competition.” For example, when a male dragonfly trying to mate discovers sperm already stored in the female’s genital chamber he uses parts of his genitalia to dig out and discard his competitor’s sperm. He copulates with the “virginized” female, who then carries his sperm. The male may then guard the impregnated female as she lays eggs carrying his genes.

Why one male removes the sperm of another before copulating is unclear, although several theories have been advanced. One is that strong and aggressive males have a better chance of fathering strong and aggressive offspring. Another is that males from previous matings failed to guard the female prior to egg-laying. Yet another suggests that a male removes older sperm to ensure that fresh (viable) sperm inseminate the female. Regardless, it seems obvious that there must be an evolutionary reason for this kind of sperm competition. (Gullan and Cranston, The Insects, Blackwell Pub., 2005; and other sources)

• Researchers in Hungary projected two images of dogs on a screen. The images were of the same dog, except one was 30 percent larger than the other. Recordings of food-growls from a large dog and a small dog were played on a speaker behind the screen. Twenty-four dogs were tested to see which image they focused on as they listened to large and small dog growls. Twenty of the dogs looked first and for a longer period of time at the dog whose size matched the growl. The researchers concluded that “…matching a sound to a photograph is a complex cognitive talent previously [once] seen only in primates.” (Science, Dec. 24, 2010; PLoS ONE on line, Dec. 15, 2010)

• The controversy rages on about whether global warming is occurring and, if so, what are man’s contributions to the phenomenon. Today everyone seems to be an expert on what’s happening (or what’s going to happen). Do many climate scientists support the view that global warming is occurring and that man plays a role in accelerating such change? Recently, Anderegg et al analyzed the views of climate experts who regularly publish on the subject of global change. A dataset was established of 1,372 climate researchers and their publication record, along with the number of times their studies were cited in the literature. The data showed that 97 – 98 percent of the most active climate researchers support the view that global warming is real and that man is contributing to climate change. Denialists, of course, argue that these scientists were all biased by each other’s findings. However, they forget that scientists take great pleasure in proving another scientist wrong. (Proceedings of the National Academy of Sciences, vol. 107, no. 52, 2010 – note: this is one of the most prestigious scientific publications in the world)

• Mushrooms emit and secrete chemicals that attract insects, especially flies, and such chemicals can actually stun or kill. Some of these chemicals can cause hallucinations and even death in humans. Keeping this in mind, one theory as to why many mushrooms are called “toadstools” is the belief that toads station themselves near mushrooms so they can snap up and eat insects that stray into the path of their long tongues. But it is unlikely that toads actually sit on mushrooms. Another mushroom snippet is that, at one time, puffballs were called “puckfists” in England, which means “fairy fart.” In parts of Spain they were called “pedo de lobos,” and in France, “pet de loup,” both meaning “fart of the wolf.” (Morgan, A., Toads and Toadstools, Celestial Arts, Berkeley, CA, 1995; other sources)