A PHYLOGENETIC REEVALUATION OF THE GENUS GAVIA (AVES: GAVIIFORMES) USING NEXT-GENERATION SEQUENCING

<p>Avian phylogenetic analysis based on DNA sequences, rather than morphological characters, has been used in recent decades to resolve systematic relationships. Advancements in molecular techniques have improved avian phylogenetics and have led to new insights on the relationships between and within taxa. Loons (Aves: Gaviiformes) are one of the oldest living lineages of birds, and the order includes five extant species. The morphological cladogram of <em>Gavia</em> placed <em>G. arctica</em> as a sister species to <em>G. pacifica</em>. However, a more recent study based on mtDNA resulted in a discordant tree splitting the <em>G</em>. <em>arctica</em>/<em>G. pacifica</em> clade, and placed <em>G. pacifica</em> as sister to the (<em>G. immer</em>, <em>G</em>. <em>adamsii</em>) clade. These hypotheses were tested using next-generation sequencing (NGS) data in the form of a RAD-tag dataset comprising 232,094 bps from 2502 variable loci. Bayesian inference, Maximum Likelihood, and Maximum Parsimony phylogenetic analyses of a concatenated dataset strongly supported the traditional phylogeny (<em>G. stellata</em>, ((<em>G. arctica</em>, <em>G. pacifica</em>), (<em>G</em>. <em>adamsii</em>, <em>G. immer</em>))), and differed from the largely mitochondrially-based hypothesis that placed <em>G. pacifica</em> sister to the (<em>G. immer</em>, <em>G. adamsii</em>) clade. Both internally- and externally-calibrated molecular clock based estimates of divergence dates placed the most recent common ancestor of modern loons in the early Miocene, which is earlier than previously thought, ~21.4 mya (20-22.8 mya) provides a more parsimonious explanation for body size evolution in loons.</p>

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Biology

Year dc:date.available

2014

Author dc:creator

• Sprengelmeyer, Quentin D

Contributors dc:contributor

• Dr. Alec Lindsay

• Gavia
• avian phylogenetics
• next-generation sequencing
• evolution
• RAD-tags

Repository record dc:identifier

https://commons.nmu.edu/theses/1

OAI identifier oai:identifier

oai:commons.nmu.edu:theses-1017