Convergent evolution of life habit and shell shape in scallops (Bivalvia: Pectinidae) with a description of a new genus

Abstract

Collectively, our results illustrate that both the evolutionary processes of convergence and parallelism generated repeated life habit states in the scallops. Bias in the types of habit transitions observed may indicate constraints due to physical or ontogenetic limitations of particular phenotypes. Recessing to permanent attachment Recessing to byssal attachment Recessing to free-living Recessing to gliding Permanent attachment* to byssal attachment Permanent attachment to free-living Permanent attachment to recessing Permanent attachment to gliding Byssal attachment to permanent attachment (2 cementing; 1 nestling) Byssal attachment to free-living Byssal attachment to recessing Byssal attachment to gliding Free-living to permanent attachment Free-living to byssal attachment Free-living to recessing Free-living to gliding Gliding to permanent attachment Gliding to byssal attachment Gliding to recessing Gliding to free-living Total number of transitions 17 *Cementing and nestling are grouped together under permanent attachment.