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.