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University of Mississippi

Phylogeography of the Malagasy Ant Species Otontomachus coquereli

Abstract

dc:description.abstract

<p>Madagascar is an extremely diverse and geographically complex area boasting levels of endemism that blatantly raise questions about their origins. There is evidence that these endemics arose via insitu diversification during Madagascar's ~88 million year isolation, even though it was essentially in the middle of Gondwana with ample opportunity to acquire inhabitants. Madagascar's high levels of diversity and endemism make it an ideal location to study speciation, especially considering the evidence that such high levels speciation occurred in Madagascar itself. Several hypotheses have been formulated to relate the complex geography to genetic divergence, and thereby speciation. I explore three hypotheses concerning the effect of mountains, rivers, and watersheds on the genetic distribution of the endemic Malagasy ant species Odontomachus coquereli. I recovered three genetic clusters from STRUCTURE arranged from north to south. Genetic diversity in these clusters decreases southward, suggesting a southward migration. Divergence time analysis in IMa2 indicates that these clusters were formed by splits during the last two consecutive ice ages, and the geographical positioning of these clusters indicates that these splits coinciding with ice ages were aided by different montane refugia within the species. Together, the data show that climate change and refugia have been the driving force of genetic structuration in this species.</p>

Degree

thesis:*
Name thesis:degree_name
M.S. in Biological Science
Level thesis:degree_level
Thesis
Discipline thesis:degree_discipline
Biology
Year dc:date.available
2013

Author and committee

dc:creator, dc:contributor.*
Author dc:creator
  • Jackson, Jason
Contributors dc:contributor
  • Brice P. Noonan
  • Rebecca Symula
  • Ryan Garrick

Subjects

dc:subject × 4

Identifiers

dc:identifier.*
Repository record dc:identifier
https://egrove.olemiss.edu/etd/1269
OAI identifier oai:identifier
oai:egrove.olemiss.edu:etd-2268

Chain of custody

source
Harvested from
University of Mississippi
Base URL
egrove.olemiss.edu/do/oai/
Last updated
2026-07-24
Source record
OAI-PMH GetRecord
citation

Jackson, Jason. Phylogeography of the Malagasy Ant Species Otontomachus coquereli. Thesis thesis, 2013. https://egrove.olemiss.edu/etd/1269