Land bridge and long-distance dispersal——Old views, new evidence

The theory of sea-floor spreading and continental drift is one of the most important achievements in the last century with large ramification for biogeography1]. Similarly, cladistics, which was started in the 1960s, has been widely employed in systemati…

Land bridge and long-distance dispersal—Old views, new evidence

The study of land bridge based on con- tinental drift1) and long-distance dispersal are gaining increasing attention in biogeography. We review several major dispersal theories including the Mal- pigiacea route, patterns of chameleon dispersal and the floating island model. The Malpigiaceae route indicates that the Malpigiaceae family originated in northern South America and that members of several clades migrated into North America and subsequently moved via north Atlantic land connections into the Old World starting in the Eocene. This route may also explain many other pantropic disjunction patterns, including some Chinese plants disjunctions, involving South America. Not all biogeographical distribution patterns can be explained by vicariance theory, so more research, including chameleon distribution, has recently focused on long-distance dispersal. The lat- est analyses suggest that chameleons have dis- persed over long-distances from Madagascar on several occasions. The floating island model would explain flora and fauna similarities between South America and Africa. Studying long-distance dispersal mechanisms is important for understanding distribu- tion patterns and even the spread of pandemics. More research on the specific implications of long- distance dispersal for biogeography is necessary.