Genetic structure of three populations of the ‘living fossil’ brachiopod Lingula from Queensland, Australia

Abstract
An electrophoretic survey of enzyme variation demonstrates that the genomes of 3 populations of the inarticulate brachiopod Lingula contain a higher level of variability than the average for marine, tropical invertebrates and for other brachiopods. Genetic distances between populations from localities up to 1200 km apart were very small, indicating that the populations belong to a single species, L. anatina Lamarck. Larval dispersal is capable of maintaining a homogeneous gene pool over this range. It is predicted that the dispersal mechanism is sufficiently efficacious to ensure gene-flow throughout most of the Indo-West Pacific distribution of Lingula. Further investigations of genetic distance should support the hypothesis, based on studies of adult and larval morphology, that many presently recognized species should be reassigned to L. anatina.