Seminars

The Ecology and Evolutionary Biology Department has been working hard and monitoring, as well as planning, for COVID-19/Coronavirus and the safety of the UCLA community. We understand that we live in very uncertain times and, with news about the virus changing rapidly, it is hard to digest everything we are reading and hearing from all of the different news outlets. Please know the department is committed to working in everyone’s best interest—students, faculty, staff, and community at large.

We have been mandated by the Chancellor’s Office that there be no hosting of any in-person event/gathering/meeting, of any size, during the duration of Spring quarter 2020. With this, all departmental seminars are canceled for the quarter. We are looking to reschedule speakers in the upcoming academic year. We appreciate your understanding at this time.

February 26, 2020

12:00pm The Hershey Hall Grand Salon, Room 158, Hershey Hall

Jesse Shapiro
Canada Research Chair, Microbial Evolutionary Genomics, Department of Biological Sciences, Université de Montréal

" Does diversity beget diversity in microbiomes "

Microbes are embedded in complex communities where they engage in a wide array of intra- and inter-specific interactions. The extent to which these interactions drive or impede microbiome diversity is not well understood. Two contrasting hypotheses have been put forward to explain how species interactions could influence diversity. ‘Ecological Controls’ (EC) predicts a negative relationship, where the evolution or migration of novel types is constrained as available niches become filled. In contrast, ‘Diversity Begets Diversity’ (DBD) predicts a positive relationship, with existing diversity promoting the accumulation of further diversity via niche construction and other interactions. Using the Earth Microbiome Project, the largest standardized survey of global biodiversity to date, we provide support for DBD as a widespread driver of microbiome diversity. In diverse biomes such as soil, DBD reaches a plateau, which is consistent with increasingly saturated niche space and a greater importance of abiotic factors relative to biotic interactions in limiting diversity. Resident genera that are strongly associated with a particular biome show a stronger DBD relationship than generalists or migrants, presumably because niches were already filled by residents. Genera with larger genomes exhibit a stronger DBD response, which could be due to a higher potential for metabolic interactions and niche construction offered by more diverse gene repertoires. Our results demonstrate a general scaling between levels of community diversity, with broad implications for modelling and predicting microbial ecosystem function and stability.

Refreshments will be served at 11:40 a.m.


Host: Nandita Garud