9701052 CAIRA Tapeworms are obligate flatworm parasites that are often restricted to specific host animals. Many tapeworm species have been associated with their hosts for long periods of time. Understanding the phylogenetic history of tapeworms is significant to biologists, who wish to understand the consequences of shared history on host and parasite species, and to lessen the harmful effects of tapeworms on humans and domesticated animals. The phylogenetic history of tapeworms has been difficult to reconstruct, because morphological characters are few and difficult to interpret, fossils are absent, and investigations on molecular characters have not been conducted. In this research, Janine Caira, Chris Simon and doctoral candidate Peter Olson will infer the phylogenetic history of tapeworms by sequencing the nucleus-encoded 18S-like ribosomal RNA gene, from representative species in each of 14 recognized major groups (orders) of tapeworms, and conducting a comparative analysis of these sequences. The work will provide a foundation with which to test hypotheses of tapeworm phylogenetic history based on morphological, ecological, and other types of evidence. In particular, the researchers will determine whether the tapeworms placed within an order share a common history (are Omonophyletic groupsO) or not.
