{"687839":{"#nid":"687839","#data":{"type":"event","title":"EAS Planetary \u0026 Astrobiology Seminar - Dr. Anthony Burnetti","body":[{"value":"\u003Cp\u003ELife has transformed the Earth, with the transduction of matter and energy through metabolism enabling cascading changes. Many of the greatest innovations in the history of life on Earth, however, are \u2018evolutionary singularities\u2019 \u2013 from the origin of life itself to eukaryogenesis to nitrogen fixation, they have appeared precisely once and gone on to change the world. Why are these innovations singular \u2013 are they very difficult to evolve with us only observing them due to anthropic selection effects, or do eco-evolutionary forces suppress the origin of newcomers in the face of incumbents? To approach this question, we study the evolution of phototrophy: the ability to use light for metabolic energy, one of the most significant metabolic innovations of all time. Unlike other singular innovations, this was invented exactly twice \u2013 chlorophototrophy and retinalophototrophy. This \u2018dual singularity\u2019 presents a unique opportunity to study the origins of evolutionary innovations: while apparently accessible enough to evolve twice, something has nonetheless limited its origins to only two. We find that these two forms cleanly ecologically partition phototrophic niche space, suggesting that each of them lays down an \u2018evolutionary priority effect\u2019 preventing the evolution of newcomers sufficiently similar to itself. This suggests that other singular innovations could be singular not due to difficulty of evolution, but due to eco-evolutionary feedbacks preventing the evolution of sufficiently similar forms. This further suggests that many major innovations taken to represent \u2018hard steps\u2019 in the evolution of a biosphere may instead be simpler to evolve than previously thought.\u003C\/p\u003E\u003Cp\u003E*Refreshments: 10:30 AM - 11:00 AM (ES\u0026amp;T L1175)\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003ELife has transformed the Earth, with the transduction of matter and energy through metabolism enabling cascading changes. Many of the greatest innovations in the history of life on Earth, however, are \u2018evolutionary singularities\u2019 \u2013 from the origin of life itself to eukaryogenesis to nitrogen fixation, they have appeared precisely once and gone on to change the world. Why are these innovations singular \u2013 are they very difficult to evolve with us only observing them due to anthropic selection effects, or do eco-evolutionary forces suppress the origin of newcomers in the face of incumbents? To approach this question, we study the evolution of phototrophy: the ability to use light for metabolic energy, one of the most significant metabolic innovations of all time. Unlike other singular innovations, this was invented exactly twice \u2013 chlorophototrophy and retinalophototrophy. This \u2018dual singularity\u2019 presents a unique opportunity to study the origins of evolutionary innovations: while apparently accessible enough to evolve twice, something has nonetheless limited its origins to only two. We find that these two forms cleanly ecologically partition phototrophic niche space, suggesting that each of them lays down an \u2018evolutionary priority effect\u2019 preventing the evolution of newcomers sufficiently similar to itself. This suggests that other singular innovations could be singular not due to difficulty of evolution, but due to eco-evolutionary feedbacks preventing the evolution of sufficiently similar forms. This further suggests that many major innovations taken to represent \u2018hard steps\u2019 in the evolution of a biosphere may instead be simpler to evolve than previously thought.\u003C\/p\u003E\u003Cp\u003E*Refreshments: 10:30 AM - 11:00 AM (ES\u0026amp;T L1175)\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"The evolution of phototrophy: ecology, evolutionary singularities, and what it means for major innovations"}],"uid":"36678","created_gmt":"2026-01-30 13:40:56","changed_gmt":"2026-02-05 17:24:14","author":"tbuchanan9","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2026-02-06T11:00:00-05:00","event_time_end":"2026-02-06T12:00:00-05:00","event_time_end_last":"2026-02-06T12:00:00-05:00","gmt_time_start":"2026-02-06 16:00:00","gmt_time_end":"2026-02-06 17:00:00","gmt_time_end_last":"2026-02-06 17:00:00","rrule":null,"timezone":"America\/New_York"},"location":"EST L1175","extras":["free_food"],"hg_media":{"679132":{"id":"679132","type":"image","title":"Burnetti\u0027s Headshot","body":null,"created":"1769780702","gmt_created":"2026-01-30 13:45:02","changed":"1769780702","gmt_changed":"2026-01-30 13:45:02","alt":"Burnetti\u0027s Headshot","file":{"fid":"263254","name":"Burnetti---Headshot.jpg","image_path":"\/sites\/default\/files\/2026\/01\/30\/Burnetti---Headshot.jpg","image_full_path":"http:\/\/hg.gatech.edu\/\/sites\/default\/files\/2026\/01\/30\/Burnetti---Headshot.jpg","mime":"image\/jpeg","size":385540,"path_740":"http:\/\/hg.gatech.edu\/sites\/default\/files\/styles\/740xx_scale\/public\/2026\/01\/30\/Burnetti---Headshot.jpg?itok=a1hSaENN"}}},"media_ids":["679132"],"related_links":[{"url":"https:\/\/scholar.google.com\/citations?user=ZrHsEhUAAAAJ\u0026hl=en\u0026oi=ao","title":""}],"groups":[{"id":"364801","name":"School of Earth and Atmospheric Sciences (EAS)"},{"id":"660370","name":"Space"}],"categories":[],"keywords":[{"id":"175623","name":"EAS Seminar"},{"id":"722","name":"Astrobiology"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}