In Darwin’s footsteps
Christoph Dieffenbacher
Zoologists and evolutionary biologists of the University of Basel are diving for cichlids in the great lakes of Eastern Africa to examine them morphologically and genetically. (Images: Robert Huber, Adrian Indermaur)
-
In Darwin’s footsteps: In the great lakes of east Africa, zoologists and evolutionary biologists of the University of Basel are diving for cichlids, so that they can later study their morphology and genetics. (Photo: Adrian Indermaur)link.zoom -
One among many: Scientists have described more than 200 different cichlid species from Lake Tanganyika. There are also dozens of undescribed species, such as fish number LGC5 (Petrochromis sp. “rainbow”) from the Basel collection. The European Research Council (ERC) has provided funding of two million euros for the project Cichlid X, which aims to study the full range of cichlid species from Lake Tanganyika. (Photo: Adrian Indermaur)link.zoom -
Expedition to the great lake: At more than 650 km long and nearly 1,500 m deep, Lake Tanganyika in east Africa is the largest body of fresh water on the African continent. The lake is renowned among biologists for its unusually diverse cichlid population. The Basel zoologists use a specially adapted fishing boat to survey the lake s many different species of cichlids. The researchers travels take them to the remotest parts of Lake Tanganyika, such as the Mahale Mountains in Tanzania. (Photo: Adrian Indermaur)link.zoom -
Turning the beach into a laboratory: The freshly caught cichlids are measured, weighed, and photographed. The researchers take DNA samples before preserving the fish for further exa mination. The Basel scientists strange activities are often a source of general amusement for a whole crowd of children. (Photo: Adrian Indermaur)link.zoom -
A little bit of Africa in Basel: Back at the University of Basel’s Zoological Institute, the cichlids are sorted and added to the ever-growing collection. Later the fish are put through a CT scan in the laboratory so that their specific environmental adaptations can be studied. Each species also has its genome sequenced. (Photo: Robert Huber)link.zoom
More than 150 years ago, the English naturalist Charles Darwin realized that living organisms change by adapting to their environment. As they adapt to different surroundings, whole new species can arise. Thus almost 2,000 new species of cichlids have evolved in the great lakes of east Africa alone – Lake Tanganyika, Lake Malawi, and Lake Victoria.
These tropical freshwater fish, which can also be found swimming around our fish tanks, vary greatly in appearance. Their basic shape is oval, rather elongated, and flattened at the sides, but they have differently shaped mouths, depending on their diet. According to Professor Walter Salzburger, a zoologist and evolutionary biologist at Basel University, “Cichlids are fascinating model organisms for understanding how biological diversity arises.” The African lakes are probably the only place on earth where such a huge number and variety of species have developed through adaption to different ecological niches – and in a relatively explosive way.
Salzburger, who is originally from the Tyrol region, flies to east Africa with his team at least twice a year. There, the zoologists spend a few weeks diving for cichlids, chasing them into nets, fishing for them, trapping them, or buying them from local fishermen, so that they can later study their morphology and genetics. And it isn’t uncommon for a fish to end up in a frying pan as dinner for the visitors from Basel.
Walter Salzburger joined the zoological institute of the University of Basel in 2007 as assistant professor. In his research, the zoologist focuses on the evolution of cichlids. He also conducts research into vertebrates of the Alpine region.