{"660441":{"#nid":"660441","#data":{"type":"event","title":"PhD Proposal by Aaron Pfennig","body":[{"value":"\u003Cp\u003EQuantitative Biosciences Thesis Proposal\u003Cbr \/\u003E\r\nOpen to the community\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cstrong\u003EAaron Pfennig\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\n\u003Cstrong\u003ETheoretical and empirical population genetics of admixture and introgression\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EFriday, September 2, 2022\u003C\/p\u003E\r\n\r\n\u003Cp\u003E11:00 am Eastern Time\u003C\/p\u003E\r\n\r\n\u003Cp\u003EEBB Krone - Children\u0026#39;s Healthcare of Atlanta Seminar Room (room #1005)\u003C\/p\u003E\r\n\r\n\u003Cp\u003EZoom Link: \u003Ca href=\u0022https:\/\/gatech.zoom.us\/j\/97879627092\u0022\u003Ehttps:\/\/gatech.zoom.us\/j\/97879627092\u003C\/a\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\n\u003Cstrong\u003EThesis Advisor:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Joseph Lachance\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\n\u003Cstrong\u003ECommittee Members:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EDr. Annalise Paaby\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\nDr. Patrick McGrath\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\nDr. I. King Jordan\u003C\/p\u003E\r\n\r\n\u003Cp\u003ESchool of Biological Sciences\u003C\/p\u003E\r\n\r\n\u003Cp\u003EGeorgia Institute of Technology\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\n\u003Cstrong\u003ESummary:\u003C\/strong\u003E\u003C\/p\u003E\r\n\r\n\u003Cp\u003EAdmixture and introgression are central components of human evolution. Large-scale\u003C\/p\u003E\r\n\r\n\u003Cp\u003Emovements of people have allowed gene flow between previously isolated extant populations,\u003C\/p\u003E\r\n\r\n\u003Cp\u003Ecreating admixed populations (e.g., African-Americans). In addition, historically anatomically\u003C\/p\u003E\r\n\r\n\u003Cp\u003Emodern humans interbred with archaic hominins on multiple occasions, i.e., with Neanderthals\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eand Denisovans. For these reasons, admixture and introgression are crucial sources of human\u003C\/p\u003E\r\n\r\n\u003Cp\u003Egenetic variation. Thus, improving our understanding of the role and implications of admixture\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eand introgression during human evolution will be invaluable to human health in the era of\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eprecision medicine.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\nIn the first part of this thesis proposal, I aim to explore population genetics models for estimating\u003C\/p\u003E\r\n\r\n\u003Cp\u003Emagnitudes of sex-biased admixture from X chromosomal and autosomal ancestry proportions. I\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eevaluate their robustness to noisy data and violations of demographic assumptions using a\u003C\/p\u003E\r\n\r\n\u003Cp\u003Esensitivity analysis and forward simulations. Knowing the confounding effects of population\u003C\/p\u003E\r\n\r\n\u003Cp\u003Estructure will help to improve the interpretability of such models. To further improve the\u003C\/p\u003E\r\n\r\n\u003Cp\u003Einterpretability of such models, I also describe an approach for obtaining confidence intervals for\u003C\/p\u003E\r\n\r\n\u003Cp\u003Esex bias estimates.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\nIn the second part, I propose a theoretical population genetics model that accounts for fitness\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eeffects that can arise from the heterogeneous background in hybrid genomes. I aim to examine\u003C\/p\u003E\r\n\r\n\u003Cp\u003Ethe impact of such fitness effects on the evolutionary dynamics of an unlinked introgressed\u003C\/p\u003E\r\n\r\n\u003Cp\u003Emarker allele. Specifically, I derive expressions for the fixation probability of an introgressed\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eallele using diffusion approximations and branching processes.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u003Cbr \/\u003E\r\nLastly, I propose to study the legacy of archaic introgression in African Americans. A s\u003C\/p\u003E\r\n\r\n\u003Cp\u003ENeanderthal interbreeding occurred in Eurasia, many archaic alleles were only recently\u003C\/p\u003E\r\n\r\n\u003Cp\u003E(re-)exposed to human-specific alleles in genomes of African-Americans, allowing us to study\u003C\/p\u003E\r\n\r\n\u003Cp\u003Ethe dynamics in real-time. Therefore, studying introgressed DNA in African-American genomes\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eallows testing whether archaic variants are still selected against and what their phenotypic\u003C\/p\u003E\r\n\r\n\u003Cp\u003Eeffects are in African-Americans, among others.\u003C\/p\u003E\r\n\r\n\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\r\n","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Theoretical and empirical population genetics of admixture and introgression"}],"uid":"27707","created_gmt":"2022-08-23 18:18:11","changed_gmt":"2022-08-23 18:18:11","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2022-09-02T12:00:00-04:00","event_time_end":"2022-09-02T14:00:00-04:00","event_time_end_last":"2022-09-02T14:00:00-04:00","gmt_time_start":"2022-09-02 16:00:00","gmt_time_end":"2022-09-02 18:00:00","gmt_time_end_last":"2022-09-02 18:00:00","rrule":null,"timezone":"America\/New_York"},"extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"102851","name":"Phd proposal"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78761","name":"Faculty\/Staff"},{"id":"78771","name":"Public"},{"id":"78751","name":"Undergraduate students"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}