Examining Polychaete speciation along a geographic gradient in the northeast pacific ocean region
Primary Investigator
Dr. Gustav Paulay | Curator of Invertebrate Zoology
Florida Museum of Natural History & UF Department of Biology
After volunteering in the Florida Museum IZ department, I became involved in this project at the end of the Fall 2023 semester.
To read more about the project
Polychaetes, or marine worms, like many invertebrates, have a robust biodiversity that is less studied than the biodiversity of terrestrial organisms.
Key Background
Speciation can occur by isolation, in which geographic isolation of population groups restricts gene flow. Large ocean distances ultimately result in divergences to the point of speciation. This can also be referred to as allopatric speciation.
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When species undergo differentiation spatially, they continue to differentiate until reaching a sufficient distinction that they become reproductively isolated, after which they can become sympatric.
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In addition to isolation, selection can also facilitate speciation. This can happen along environmental gradients, even along continuous coastlines. Differing environmental conditions that occur along this gradient can lead to differential selection and adaptation of populations, and eventually create a separation between species. This process is known as ecological speciation.
With that in mind...
My project will be a search for phylogenetic breaks along the northeast pacific coast that indicate species differentiation. This is predicted by ecological speciation, the mechanism in which speciation can occur along a geographic gradient. With that considered, I believe a potential driver of this speciation to be temperature, resulting in a stratification of species latitudinally. Using sequences and samples available from the Florida Museum of Natural History and the Los Angeles County Museum, this project will build a phylogeny of polychaetes from the northeast Pacific Ocean region; I will look for sister lineages that show allopatric distribution and compare their ranges across all samples. The phylogenetic information will be used to construct a map of divergence diversity, which will inform patterns of speciation by geography. This project will start with a collection of >1100 COI sequences of west coast polychaetes from FLMNH that will be expanded with additional data taken from LACM, BOLD (Barcode of Life Database) and additional sequencing.