{ "134778-21875096": { "datetime_modified":"20250410T100925", "datetime_start":"20250418T100000", "datetime_end":"20250418T120000", "has_end_time":1, "date_start":"2025-04-18", "date_end":"2025-04-18", "time_start":"10:00:00", "time_end":"12:00:00", "time_zone":"America\/Detroit", "event_title":"EEB Student Dissertation Defense - Selections in molecular and phenotypic evolution", "occurrence_title":"", "combined_title":"EEB Student Dissertation Defense - Selections in molecular and phenotypic evolution: Siliang Song", "event_subtitle":"Siliang Song", "event_type":"Workshop \/ Seminar", "event_type_id":"21", "description":"Dissertation Title: Selections in molecular and phenotypic evolution\r\n\r\nDissertation Abstract: Selection plays an undoubtedly important role in evolution. My dissertation explores the pattern and impact of selection at both molecular and phenotypic levels. In Chapter 1, I challenged the neutral theory of molecular evolution by demonstrating that beneficial mutations are way more abundant than previously assumed. I proposed an adaptive tracking theory to reconcile this finding with the low substitution rate inferred from comparative genomic patterns; under this theory, a natural population is always adapting to the rapidly changing environment. In Chapter 2, I investigated the genetic maintenance of human same-sex sexual behavior (SSB) and showed that modern contraception had disrupted previously hypothesized evolutionary mechanisms that maintained SSB-associated alleles. In Chapter 3, I further distinguished between bisexual behavior (BSB) and exclusive SSB (eSSB) in their genetic basis, finding that BSB-associated alleles may confer reproductive advantages whereas eSSB-associated alleles are likely under negative selection. In Chapter 4, I examined the genetic architecture of the human sex ratio, identified the impact of large measurement error in inferring the heritability of sex ratio, and provided genomic evidence supporting Fisher\u2019s principle. Finally, I addressed methodological aspects of evolutionary analysis: in Chapter 5, I uncovered biases in inferring fitness landscape ruggedness due to measurement errors and proposed a correction; in Chapter 6, I introduced \u201ceffective fitness\u201d as a more informative metric to quantify fluctuating selection with genetic drift. 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One more Friday. One more reason to smile.\r\nJoin connect@michiganengineering for the last Fragel Friday of the semester this Friday (4\/18) at 10 AM\u2014your final chance to score a fresh, FREE fragel before we break for the summer (limited quantities).\r\n\r\nWhether you missed us last week or just can\u2019t get enough, we\u2019ve got you covered. Swing by the Grove, fuel up, and catch up with friends before finals take over.\r\n\r\nThis is it until September\u2014don\u2019t miss your fragel fix!", "occurrence_notes":null, "guid":"135018-21875962@events.umich.edu", "permalink":"http:\/\/events.umich.edu\/event\/135018", "building_id":"0", "building_name":"The Grove", "campus_maps_id":"564", "room":"", "location_name":"The Grove", "has_livestream":0, "cost":"", "tags":["Undergraduate Students","Undergraduate","Outdoors","North Campus","Michigan Engineering","In Person","Graduate Students","Graduate","Free","Food","Engineering","Community Engagement","Community","College Of Engineering","Breakfast"], "website":"https:\/\/connect.engin.umich.edu\/", "sponsors":[ { "group_name":"connect@michiganengineering", "group_id":"4879", "website":"" } ], "image_url":"https:\/\/events.umich.edu\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "styled_images":{ "event_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_thumb\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_large":"https:\/\/events.umich.edu\/media\/cache\/event_large\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_large_2x":"https:\/\/events.umich.edu\/media\/cache\/event_large_2x\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/event_large_lightbox\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "group_thumb":"https:\/\/events.umich.edu\/media\/cache\/group_thumb\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "group_thumb_square":"https:\/\/events.umich.edu\/media\/cache\/group_thumb_square\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "group_large":"https:\/\/events.umich.edu\/media\/cache\/group_large\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "group_large_lightbox":"https:\/\/events.umich.edu\/media\/cache\/group_large_lightbox\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_large_crop":"https:\/\/events.umich.edu\/media\/cache\/event_large_crop\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_list":"https:\/\/events.umich.edu\/media\/cache\/event_list\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_list_2x":"https:\/\/events.umich.edu\/media\/cache\/event_list_2x\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_grid":"https:\/\/events.umich.edu\/media\/cache\/event_grid\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_grid_2x":"https:\/\/events.umich.edu\/media\/cache\/event_grid_2x\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_feature_large":"https:\/\/events.umich.edu\/media\/cache\/event_feature_large\/media\/attachments\/2025\/04\/event_135018_original-1.jpg", "event_feature_thumb":"https:\/\/events.umich.edu\/media\/cache\/event_feature_thumb\/media\/attachments\/2025\/04\/event_135018_original-1.jpg" }, "occurrence_count":1, "first_occurrence":21875962 } }