Dissertation/Thesis Abstract

Myriad Mirids: The spectacular radiation of Pseudoloxops (Hemiptera: Miridae) plant bugs in French Polynesia (and the kids that love them!)
by Balukjian, Bradley James, Ph.D., University of California, Berkeley, 2013, 373; 3593769
Abstract (Summary)

In the first chapter, we revise the taxonomy of a lineage of plant bugs (Hemiptera: Miridae) that has radiated in the islands of French Polynesia. Six species of endemic Pseudoloxops plant bugs were previously known from two islands in French Polynesia, indicating a small radiation. We collected ecological, morphological, molecular, and geographical data for hundreds of fresh and historical Pseudoloxops specimens, expanding the genus' range to nine islands in two archipelagoes (the Austral and Society Islands). We combined all of the above data sources in an iterative integrative taxonomy framework to test the six existing species hypotheses and to search for new diversity.

In the second chapter, we explore the relative importance of ecology and geographic isolation in this lineage to provide a first approximation of whether the radiation was adaptive or non-adaptive. We collected Pseudoloxops from a wide range of plants, with 27 species in 25 different plant families and 13 orders. We then inferred a combined Bayesian molecular phylogeny from three genes, including 25 of the 26 known Pseudoloxops species, to examine the roles of plant affiliation and geography (island distribution) in speciation. We reconstructed the ancestral states using parsimony for these two characters, and found 12 speciation events that were well-supported in the phylogeny. Both plant-switching and island-hopping were correlated with speciation. For the 7 speciation events for which we could unequivocally determine plant affiliation before and after speciation, 4 were associated with a plant shift. For the 8 speciation events where island distribution could be reconstructed, two involved shifts to a new island. There were 5 cases for which we could determine both character states before and after speciation. In three of them, speciation occurred within the same locality with a switch in plant taxonomic order, suggesting that the lineage has great dietary versatility. However, much more research into feeding needs to be conducted, as anecdotal evidence from Pseudoloxops outside of French Polynesia suggests they may be facultative predators. In the other two speciation events, there was neither a geographic shift nor a change in plant affiliation, suggesting some other mechanism for speciation. Based on our results, both plant-switching and geography have played a role in the diversification of this radiation.

In the third chapter, we address the larger societal impact of taxonomic and biodiversity research by examining the effect of a natural history-driven curriculum on elementary schoolchildren's scientific knowledge. While studies have demonstrated the potential for natural history education to improve children's attitudes towards and knowledge of science and nature, few studies have been done in areas where indigenous culture heavily influences children's worldview. The lead author taught a nine-month natural history/biodiversity class focused on insects and plants to fifth-graders at the Pao Pao elementary school on the French Polynesian island of Moorea and tested their scientific knowledge before and after receiving the program. We compared their results to a control that did not receive the program, and while both cohorts improved, the experimental group's improvement was significantly greater (mean of 82.2% vs. 30.5%). We performed a delayed post-test evaluation three years after the conclusion of the program with a subset of the experimental cohort to test their retention and interest in science. Finally, the qualitative coding of the experimental group's test and survey responses revealed both the influence of indigenous culture on their scientific understanding and the appeal of taxonomy and field trips to children. When prompted for an example of a native plant, 24% of the experimental group named a plant introduced by the Polynesians, suggesting the misconception that plants with a prevalent role in indigenous culture have always been there. In the follow-up survey, 36.7% mentioned the field trips among their memories of the course, and 20% gave full scientific names for species they recalled from the class. The latter contrasts with the commonly held belief that taxonomy is too arcane to connect with the general public. (Abstract shortened by UMI.)

Indexing (document details)
Advisor: Gillespie, Rosemary G.
Commitee: Polhemus, Dan A., Ranney, Michael A., Roderick, George K.
School: University of California, Berkeley
Department: Environmental Science, Policy, and Management
School Location: United States -- California
Source: DAI-B 75/01(E), Dissertation Abstracts International
Subjects: Entomology, Systematic, Education
Keywords: Environmental education, French polynesia, Hemiptera, Integrative taxonomy, Miridae, Speciation
Publication Number: 3593769
ISBN: 978-1-303-37151-6
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