Title

Phylogeography of the Indonesian Water Python, Liasis mackloti ssp. (Squamata: Boidae: Pythoninae): A Comparative Approach Toward Resolving Phylogeny

Date of Award

2007

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biological Sciences

First Advisor

Brian R. Kreiser

Advisor Department

Biological Sciences

Abstract

Liasis mackloti is currently recognized as three subspecies (L. m. savuensis, L. m. dunni and L. m. mackloti ) inhabiting several islands of the Outer and Inner Banda Arc of islands of Indonesia's Lesser Sundas Archipelago. We used partial mitochondrial cytbchrome b sequences and morphological character states to examine and resolve the phylogenetic relationship of these three subspecies. Both molecular and morphological data sets reveal similar patterns of phylogeny. Their distribution and evolution appears to have been shaped by combined effects of dispersal and vicariance. We conducted pheromone trailing experiments to investigate the level of geographic variation present in this behavior in the macklot's python, Liasis mackloti (Serpentes: Boidae). The results of this study of the L. mackloti complex indicate that during the breeding season male pythons were able to discriminate between homotypic and heterotypic odors within each of the clades (P<0.05). However, male pythons from Timor, Semau and Roti were unable to differentiate pheromone trails produced by females from these three islands (P>0.05). Male L. m. dunni from the island of Wetar are generally longer than females and also exhibited specificity toward homotypic male trails. This homotypic male trailing behavior, in addition to several male-male combat interactions observed during the study suggests that males from Wetar may attempt to displace males for access to females. Pheromone trailing discrimination is an important pre-zygotic reproductive isolating mechanism that may have played an important role during speciation. We also present the role of dispersal and vicariance in shaping current patterns of geographic variation. Courtship behaviors were compared between three subspecies of the Indonesian water python, L. m. mackloti, L. m. savuensis , and L. m. dunni , to elucidate patterns of geographic variation in male courtship behavior in standard laboratory conditions. The insular populations of L. rmackloti ssp . within this archipelago indicate that separation between islands during the Pleistocene played a role in determining current assemblages and variation within species. We observed variation in both the frequency of occurrence and the sequence of the principal courtship behaviors and, when compared statistically, most of these behaviors differed between populations. We observed geographically unique island patterns in the sequence in which male courtship behaviors are displayed. Our data yielded the following information: (1) the courtship sequence in all three subspecies is not random; (2) the sequence of L. m. savuensis is much less complex than that of L. m. mackloti and L. m. dunni ; and (3) the tactile pelvic spurring target sites used by males on the females' dorsum is different between the three subspecies. We also determined whether sexual isolation among selected populations existed. (Abstract shortened by UMI.)