A collaboration I was lucky to be involved in led by Jesse Shapiro and PhD student Naima Madi (University of Montreal, although Jesse has now moved across the road to McGill) and with Carmen Lia Murall and Pierre Legendre has now been published. In this study, we used a vast dataset of 16S sequences from the Earth Microbiome Project (around 10 million of em!) to test whether microbiome diversification (via de novo evolution or via immigration) was positively or negatively influenced by standing microbiome diversity. As usual I am going to be lazy and leave it at that and just paste the Abstract below.
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. Historically, two contrasting hypotheses have been suggested 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 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 high-throughput amplicon sequencing data from the Earth Microbiome Project, we provide evidence that DBD is strongest in low-diversity biomes, but weaker in more diverse biomes, consistent with biotic interactions initially favouring the accumulation of diversity (as predicted by DBD). However, as niches become increasingly filled, diversity hits a plateau (as predicted by EC).
Madi, Naïma Jesse, Michiel Vos, Carmen Lia Murall, Pierre Legendre, and B. Jesse Shapiro (2020). “Does diversity beget diversity in microbiomes?.”eLife 2020;9:e58999 doi: 10.7554/eLife.58999.