ABSTRACT
In the early 1950s, biologists pulled about a dozen oysters from the New Haven harbor and shipped them to Northwestern University in Illinois, about 1,000 miles away from New Haven and in a different time zone, one hour earlier. The oysters were submerged in their original harbor water and kept in total darkness. To explore their feeding patterns, the researchers tied fi ne threads to the shells that could activate recording pens every time the oysters’ muscular movements caused the hinged shells to part or to close. Just as expected, the oysters continued to open and shut their shells as if they were still snug at the bottom of their home harbor, even though they had been displaced to another time zone, more than 1,000 miles to the west. Then, after about two weeks, something strange happened. Gradually the hour of maximal opening of the shells began to shift. Now, anyone who lives near the shore knows that the high-and low-water marks also shift gradually from day to day. Tides are synchronized not with the place of the sun in the sky; rather it is the moon’s schedule of appearance that matters, and the moon runs about 50 minutes behind the sun cycle. However, the biologists in Illinois were witnessing a daily shifting that did not correspond to the one in New Haven. After four weeks of recording and analyzing the data, the biologist determined beyond any doubt that the oysters had restabilized the rhythmic opening and closing of their shells to the tidal cycle that would occur in Evanston, Illinois, if there were an ocean in that location (see Aveni 1989; Brown 1962; Brown et al. 1970).
