What is Afrotheria?
The development of molecular techniques to explore the evolutionary relationships of animals has resulted in scientists gathering overwhelming support for a common African ancestry for several "odd" groups of mammals. This ancient radiation of African mammals, the Afrotheria, includes seven groups with little superficial resemblance to each other: the elephants, sea cows, and hyraxes; the aardvark and sengis (or elephant-shrews), and the golden-moles and tenrecs. Although some biologists do not accept this arrangement, it is still a useful and efficient assemblage to focus specialist group conservation activities. The IUCN already has active groups that include elephants and sea cows, so when the Afrotheria Specialist Group was formed in 2001, it only included the remaining five "forgotten" groups of mammals.
The Afrotheria Specialist Group deals with very few species — there is only one aardvark, 6 hyraxes, 18 sengis, 21 golden-moles, and 33 tenrecs. Many of these species have broad distributions in a wide variety of habitats, which means they are not particularly vulnerable to extinction (the aardvark, for example, and several hyraxes and sengis). However, many afrotherians are vulnerable or already endangered because they have specialized habitat requirements and restricted distributions, including some golden-moles and some forest-dwelling sengis. Several tenrecs on Madagascar are endangered due to the disappearance of forest and aquatic habitats on the island. In nearly all the cases where afrotherians are threatened or endangered, the basic problem is the disappearance of their habitat due to a variety of human activities.
The new Afrotheria Specialist Group must determine the status of many poorly known species and develop conservation strategies for those that are threatened, but it also needs to encourage research, improve coordination, and increase awareness of the importance of conserving these mammals and their habitats. The Afrotheria represents one of the major mammalian evolutionary radiations. By one count, the seven groups that make up the Afrotheria represent nearly a third of all the living orders of mammals. However, they only contribute about 77 of the 1260 or so species of mammals found in Africa and Madagascar. This means that with relatively few species extinctions, entire groups of afrotherian mammals would cease to exist, thus terminating over 100 million years of evolution in Africa and drastically reducing that region's biodiversity.
Galen B. Rathbun, Ph.D.
Peter J. Stephenson, Ph.D.