ARE THE IMPACTS OF EVENTS IN THE EARTHS HISTORY DISCERNABLE IN THE CURRENT DISTRIBUTIONS OF FRESH-WATER ALGAE

Freshwater microalgae, lacking a fossil record, have contributed littl e to the study of historical biogeography. Some of the innate difficul ties are discussed, as well as some of the more hopeful possibilities, if distribution records, morphology and DNA sequence analysis are com bined with knowledge of the earth's history. Examples of species withi n the same family showing quite different distributions are given, alo ng with suggested explanations. These include possible examples of the role played by waterfowl in dissemination of freshwater algae.