Anna C. Gonzalez

Natsci - Article II

May 11, 1998

In 1939, an angler in South Africa landed a living fossil - a coelacanth - that gave evolutionists the chance to test a theory that the coelacanth might be the missing link between bony fish and the first vertebrate to make it out of the water. The latest research has found that the fish appears to have a whole new class of immunoglobulin genes - a fourth type of organization, different from those in most vertebrates, birds and sharks.

The team of investigators, lead by geneticist Gary Litman of the University of South Florida, found that the coding genes for the coelacanth's immunoglobulin heavy chain variable region are clustered around other genes of the same type; as they are in sharks but not like the gene organization in land vertebrates and bony fish. However, unlike sharks and like those animals mentioned, the genes recombined during development. Litman argues that the coelacanths may be a transitional form between the two.