Biogeography of Cladophoropsis membranacea (Siphonocladales, Chlorophyta) as Revealed by Single Copy DNA Distances

Single copy DNA measurements were determined among isolates of Cladophoropsis membranacea from the Caribbean, Mauritania, the Canary Islands and the Red Sea using DNA-DNA hybridization. The genotypic relationships found amongst the Atlantic isolates demonstrate that the present day distribution pattern has been affected by jump dispersal. We have to reject strict trans-Atlantic vicariance and unimpeded gene flow through the Atlantic. The isolate from the Red Sea is more closely related to the Mauritanian/Caribbean isolates than to the Canarian one. This can be explained by jump dispersal around southern Africa. Any of these events should postdate the separation of the Canarian and Caribbean populations from which the isolates have been sampled.