Dinosaurs in the Attic Read Free

decaying litter of the forest floor, feeding mostly on fungus spores. It is a peaceful insect, neither an annoying pest nor a crop destroyer. Although it is extremely common (literally billions can be found in most continents of the world), its existence is unknown to all humanity save for a dozen or so entomologists; and of these, only two or three have any real interest in the bug. As I sit on the roof of this Museum and consider that here, beneath me, are some of the most beautiful, rare, and extravagant creations of nature and man, I wonder what could possibly be important enough about this little beetle to warrant its inclusion in the Museum's collections.

To answer this question, we must look back thirty or so years to the discovery of Bambara intricata. This particular bug hails from the Bimini islands, a low, windswept string of cays in the Bahamas, not far from Florida. In 1947 the Museum established a research station on North Bimini (now closed) named the Lerner Marine Laboratory. Before then, the area had seen little scientific exploration, and only two insects had been reported from the island: the mosquito (whose presence was immediately and unpleasantly apparent to the visitor) and a pretty species of butterfly. Thus, one of the first priorities was to do an insect "inventory" of the islands to collect and record the species that lived there. In 1951 a group of Museum entomologists went to Bimini and spent four months luring and trapping as many insects as they could, using nets, funnels, ultraviolet lights, and white sheets. When they were finished they had collected 109,718 insects and 27,839 arachnids, including thousands of featherwing beetles. (To capture the featherwings, they used an ingenious contraption called a Berlese funnel, which drives tiny insects out of decaying leaves, bark, and soil.) They caught so many tiny featherwings that the beetles "formed a black cloud" when the collecting vials of alcohol were shaken.

Among these thousands of specimens, the Museum scientists found that six species of feathering beetle were present on the island. Eventually the vials of alcohol were transferred to the main entomology storage area in New York City, where for fifteen years they rested in a dark cabinet.

In the mid-sixties, someone finally took an interest in the insects. A curator at the Field Museum of Natural History in Chicago, Henry Dybas, borrowed a number of the vials containing the featherwings for a research project on a strange phenomenon known as parthenogenesis—the reproduction of an animal without fertilization by the male. Dybas had evidence that many species of the featherwing beetle exist in all-female populations, reproducing without the aid of males. He wanted to examine a large number of specimens collected at the same time to see if indeed they were all female. In doing so, he developed several startling theories.

Through his examination of featherwing beetles, Dybas was able to illuminate the complex workings of a small corner of the natural world. He wondered, for example, why the beetles were so small. He wanted to know why many species or populations seemed to have done away with males. Finally, he had observed that the featherwing beetles from Bimini had no feather wings, even though the same species on the mainland possessed them. After some thought, Dybas came up with an interesting interlocking theory that explained these three questions.

First, he had reason to believe that the beetles had evolved from a larger into a smaller size, primarily because they needed to be light enough to float on the wind, and thus to occupy a niche in which smallness was an advantage. In becoming small, however, the featherwings could carry fewer and fewer eggs, since the eggs could not be "miniaturized" the way the insect could. Thus, the Bimini beetles lost the ability to carry thousands of eggs and produce many offspring at a single time, as most other insects do. Indeed, they became so