PETER D. MOORE Division of Biosphere Sciences King's College London The warming of the earth's climate following the last glaciation was interrupted in the North Atlantic region by a severe spell of cold conditions that lasted from about 10,800 to 10,000 years ago (called the "Younger Dryas" event). The cause of this setback to global warming is thought to be the diversion of ice meltwater from the North American ice sheet into the St. Lawrence River and, hence, into the North Atlantic. But

Peter D. Moore Division of Biosphere Sciences King's College London Parasitic wasps, which use nectar as a supply of energy, can detect sources by using odor cues. They are also able to locate their hosts by smells associated with them. Under experimental conditions, wasps have proved capable of learning complex associations between various odors and sources of either hosts or foods. They were then able to make choices based upon their relative hunger or motivation to lay eggs in their host o

PETER D. MOORE Department of Biosphere Sciences King's College London, U.K. Fungal epidemics in natural plant communities are influenced by a wide range of climatic and other factors, but not, apparently, by high density of the host species or by human disturbance. The outcome of periodic fungal attacks is diversification of the plant community, but diversity itself does not offer in return any protection against further epidemics. Attacks on juvenile plants can cause considerable modifica