Author Donaldson, Kim A
Title Molecular evolution of a coding and a non-coding region of the mitochondrial genome of three transisthmian species of fishes (Centropomidae: Centropomus)
book jacket
Descript 202 p
Note Source: Dissertation Abstracts International, Volume: 63-02, Section: B, page: 0694
Major Professor: Raymond R. Wilson, Jr
Thesis (Ph.D.)--University of South Florida, 2001
Fish divergence times are often inferred from DNA sequence data calibrated by rates derived from the mammalian fossil record, but it is not clear if mammalian mitochondrial DNA substitution rates are comparable enough to those of fishes for correct inferences. From comparative analysis of control region (ca. 1097 bases) and ND5/6 (890 bases) sequences from geminate species of snook (Centropomus) believed to have been separated by the Pliocene uplift of the Isthmus of Panama, this dissertation seeks to calibrate a fish divergence rate for the control region. Additionally, the phylogenetic utility of the control region and ND5/6 sequences are investigated. The most plausible general control region divergence rate of 3.2% per million years +/- 1.1% for centropomids was obtained after applying a 1% per million years divergence rate to transversion substitutions at third codon-positions of ND5/6 sequences to estimate the separation time of the fish geminate species, rather than directly applying the time suggested by the Pliocene uplift. A control region divergence rate of 2.1 per million years appeared the most conceivable when only geminate species pairs were compared to each other. However, because a segment of one ND5/6 sequence might have been corrupted by some type of interspecific recombination or introgression, the derived rates should be interpreted carefully. The 1% per million years rate is essentially a mammalian rate, so fish and mammalian divergence rates appear comparable in the studied mitochondrial DNA sequences. It appears that the three centropomid control region domains have comparable ability to resolve only the most closely related species. The maximum likelihood method appeared the most robust algorithm for analyzing the control region domains. Tests with several tree-building methods showed using the entire control region data set more consistently provided an accepted phylogeny rather than using any one domain
School code: 0206
DDC
Host Item Dissertation Abstracts International 63-02B
Subject Biology, Genetics
Biology, Zoology
0369
0472
Alt Author University of South Florida