Convergent evolution is the independent evolution of similar characteristics by means of natural selection. Convergence is a well-known phenomenon, but convergence resulting from equivalent environmental gradients has only been pursued in a few cases. The main purpose of this study was to look for evidence of convergence of life history traits between two sympatrically distributed topminnows. The two species typically separate along a stream size gradient with Fundulus notatus inhabiting the downstream environment, and F. olivaceus inhabiting the upstream headwater environment. However, there are at least three known drainages where the normal distribution pattern is reversed, and F. notatus is found upstream of F. olivaceus. Divergent life history traits are displayed in drainages with the normal distribution pattern, leading to the prediction that life history traits of headwater F. notatus (reversed distribution) will converge on those of headwater F. olivaceus (normal distribution). A field study and an energetics experiment were used to look for convergent life history traits. These data reveal convergent life history traits of headwater F. notatus on downstream F. olivaceus.
","abstract_html":"<p>Convergent evolution is the independent evolution of similar characteristics by means of natural selection. Convergence is a well-known phenomenon, but convergence resulting from equivalent environmental gradients has only been pursued in a few cases. The main purpose of this study was to look for evidence of convergence of life history traits between two sympatrically distributed topminnows. The two species typically separate along a stream size gradient with <em>Fundulus notatus</em> inhabiting the downstream environment, and <em>F. olivaceus</em> inhabiting the upstream headwater environment. However, there are at least three known drainages where the normal distribution pattern is reversed, and <em>F. notatus</em> is found upstream of <em>F. olivaceus</em>. Divergent life history traits are displayed in drainages with the normal distribution pattern, leading to the prediction that life history traits of headwater <em>F. notatus</em> (reversed distribution) will converge on those of headwater <em>F. olivaceus</em> (normal distribution). A field study and an energetics experiment were used to look for convergent life history traits. These data reveal convergent life history traits of headwater <em>F. notatus</em> on downstream <em>F. olivaceus</em>.</p>","abstract_has_math":false,"creators":["Harris, Jared Aubin"],"institution":null,"degree_name":"Master of Science (MS)","degree_level":"Masters Thesis","degree_discipline":"Biological Sciences","degree_department":null,"school":null,"contributors":["Jake Schaefer","Carl Qualls","Nathan Franssen"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2013,"date_issued":"2013-12-01T08:00:00Z","date_published":"2013-12-01T08:00:00Z","updated_at":"2026-07-24T05:45:06Z","subjects":[],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://aquila.usm.edu/masters_theses/501","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Jake Schaefer","Carl Qualls","Nathan Franssen"]},{"key":"dc:creator","label":"Author","values":["Harris, Jared Aubin"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.available","label":"Dc Date Available","values":["2018-11-14T08:00:00Z"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Biological Sciences"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Masters Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science (MS)"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://aquila.usm.edu/masters_theses/501"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Convergent evolution is the independent evolution of similar characteristics by means of natural selection. Convergence is a well-known phenomenon, but convergence resulting from equivalent environmental gradients has only been pursued in a few cases. The main purpose of this study was to look for evidence of convergence of life history traits between two sympatrically distributed topminnows. The two species typically separate along a stream size gradient with Fundulus notatus inhabiting the downstream environment, and F. olivaceus inhabiting the upstream headwater environment. However, there are at least three known drainages where the normal distribution pattern is reversed, and F. notatus is found upstream of F. olivaceus. Divergent life history traits are displayed in drainages with the normal distribution pattern, leading to the prediction that life history traits of headwater F. notatus (reversed distribution) will converge on those of headwater F. olivaceus (normal distribution). A field study and an energetics experiment were used to look for convergent life history traits. These data reveal convergent life history traits of headwater F. notatus on downstream F. olivaceus.
"]},{"key":"dc:title","label":"Title","values":["Convergence of Life History Phenotypes in Two Species of Topminnows, Fundulus notatus and Fundulus olivaceus"]}]}],"canonical_facts":{"dc:contributor":["Jake Schaefer","Carl Qualls","Nathan Franssen"],"dc:creator":["Harris, Jared Aubin"],"dc:date.available":["2018-11-14T08:00:00Z"],"dc:description.abstract":["Convergent evolution is the independent evolution of similar characteristics by means of natural selection. Convergence is a well-known phenomenon, but convergence resulting from equivalent environmental gradients has only been pursued in a few cases. The main purpose of this study was to look for evidence of convergence of life history traits between two sympatrically distributed topminnows. The two species typically separate along a stream size gradient with Fundulus notatus inhabiting the downstream environment, and F. olivaceus inhabiting the upstream headwater environment. However, there are at least three known drainages where the normal distribution pattern is reversed, and F. notatus is found upstream of F. olivaceus. Divergent life history traits are displayed in drainages with the normal distribution pattern, leading to the prediction that life history traits of headwater F. notatus (reversed distribution) will converge on those of headwater F. olivaceus (normal distribution). A field study and an energetics experiment were used to look for convergent life history traits. These data reveal convergent life history traits of headwater F. notatus on downstream F. olivaceus.
"],"dc:identifier":["https://aquila.usm.edu/masters_theses/501"],"dc:title":["Convergence of Life History Phenotypes in Two Species of Topminnows, Fundulus notatus and Fundulus olivaceus"],"thesis:degree_discipline":["Biological Sciences"],"thesis:degree_level":["Masters Thesis"],"thesis:degree_name":["Master of Science (MS)"]},"updated_at":"2026-07-24T05:45:06Z"}