Robert Drewes is a American biologist with a long fascination for the African continent, having conducted field research in 30 different countries in Africa since 1969. In this presentation, he will bring us up to date on the Academy's research and conservation efforts in São Tomé and Príncipe. These two mountainous islands together form Africa's second smallest republic (after the Seychelles Islands) and are biologically unique. They are the two middle members of a four-island chain, sometimes known as the Gulf of Guinea Islands, which is the only archipelago on earth comprised of both continental and oceanic islands. São Tomé and Príncipe arose some 2 to 4000 meters up from the ocean floor and thus have never been attached to mainland Africa. This means that the ancestors of all the plants and animals that are found on the islands today must have crossed hundreds of km of deep salt water to get there. The colonizers that make it to the islands through a various dispersal methods are then separated from their mainland founder populations and, over time, begin to accumulate genetic changes, a process we all know as evolution. Among the vertebrates found there, more than half of the 49 species and subspecies of land birds breeding on the islands are endemic and include the world's largest sunbird as well as the smallest ibis. But one of most surprising findings of all, is the presence of an amphibian fauna. This is because amphibians almost never cross saltwater barriers and are therefore considered among the poorest of dispersers. Please join us for this evening presentation to find out what else has been discovered in the Academy's many years of scientific travel to this remote island region to study the process of evolution and life on Earth.
Dr. Robert Drewes
Dr. Robert Drewes is Curator of the Department of Herpetology at the California Academy of Sciences. He completed his undergraduate degree at San Francisco State and his Ph.D. in Biology at UCLA, focusing on the evolutionary relationships of the dominant treefrog family of Africa, Madagascar, and the Seychelles Islands. His graduate career at UCLA also instilled an ongoing fascination with environmental physiology (the study of how individual organisms physically interact with the environment).
Drewes' ongoing research on the systematics, natural history, and behavior of African reptiles and amphibians began with a year-long trip to East Africa in 1969.