A grant has been awarded from the National Science Foundation to Dr. Jack Sites and Mrs. Alison Whiting at Brigham Young University to study the evolutionary patterns of limb loss in a group of Southern African lizards. Limb loss is a trend seen in many squamate groups, including snakes and various lizards. The lizard family Scincidae (skinks) is arguably the best system in which to study patterns and processes of limb loss because limb reduction (to some degree) is postulated to have occurred over 30 independent times. The southern African genus Scelotes contains species exhibiting the full range of limb reduction, from fully functional pentadactyl limbs (i.e., those with 5 digits) to complete lack thereof, with many intermediate forms. However, the evolutionary relationship among skinks is unknown. The objective of this research is to establish a robust hypothesis of phylogenetic (i.e., genealogical) relationships within southern African scincines, using both DNA sequence and skeletal data, and to evaluate the evolutionary pattern of limb loss within Scelotes in light of phylogeny. Preliminary results support multiple occurrences as well as reversals of limb loss in this group. The loss of limbs in snakes and multiple lizard groups has long been an area of intense interest. This study will lead to a greater understanding of the morphological changes associated with, and the ecological pressures that lead to limb loss, and indirectly may also help scientists understand details about the origin of snakes. In addition, studying limb loss in a group where it has occurred multiple times will lay the foundations for understanding the developmental genetic mechanisms involved in limb development.
