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Full-Text Articles in Life Sciences
Comparing The Reproductive Fitness Of Fundulus Hybrids And Their Parental Species (Fundulus Olivaceus And Fundulus Notatus) Within Mississippi Freshwater Contact Zones, Sarah Stovall
Honors Theses
Hybridization of closely related taxonomic groups within the Animal Kingdom has led to complex species interactions that are not well understood. Pre-zygotic or post-zygotic barriers complicate hybridization as a means to diversify; however, diverging hybrids may speciate and expedite evolution of involved taxa. This study pursues understanding of these intricate interactions using topminnow Fundulus notatus, Fundulus olivaceus, and their hybrids from the Fundulus notatus species complex. Persisting hybrids within riverine contact zones were hypothesized to experience barriers of hybrid breakdown from lower fitness in comparison to the pure species. Specimens were collected within four contact zones: Spring River, …
Patterns Of Genomic Introgression In Topminnow Hybrid Zones, Amanda F. Ray
Patterns Of Genomic Introgression In Topminnow Hybrid Zones, Amanda F. Ray
Honors Theses
Hybridization and introgression are two important evolutionary mechanisms that can increase genetic diversity. Interesting introgression patterns can form when parental species have genes that confer some adaptive benefit to the organism. The Fundulus notatus species complex contains species with various identifying characterisics. Fundulus notatus, the blackstripe topminnow, and Fundulus olivaceus, the blackspotted topminnow, are closely related and occupy many of the same rivers in their preferred niches. These two species often hybridize and form hybrid zones where their niches overlap. We studied two hybrid zones located in the Tombigbee River and Spring River. Within each hybrid zone, we …
Effect Of Reinforcement Selection On Mate Selection Rates Of Gambusia Affinis And Gambusia Holbrooki, Molly Stephens
Effect Of Reinforcement Selection On Mate Selection Rates Of Gambusia Affinis And Gambusia Holbrooki, Molly Stephens
Honors Theses
This study was conducted in order to investigate the effects that reinforcement selection has on non-hybridized and hybridized populations of two separate species of Gambusia (G. affinis and G. holbrooki). In order to examine if organisms from a population that had been previously exposed to hybridization would choose mates so as to not produce species hybrid offspring, 29 trials consisting of 9 different mate preference combinations and 87 individuals were recorded and analyzed. Once mate preference was determined for each female used in each trial, the effect that reproductive isolation had on reinforcement in hybrid zones was analyzed. The results …