BRENDAN BO­HAN­NAN: "Host-Mi­cro­bio­mes as Me­ta­com­mu­nit­ies"

Back­ground: Hu­mans and other an­im­als are chi­meric creatures, covered in­side and out withmi­croor­gan­isms. These mi­crobes are col­lect­ively known as an in­di­vidu­al’s ‘mi­cro­bi­o­me’,and vari­ation in mi­cro­bi­ome com­pos­i­tion across in­di­vidu­als has been linked to vari­ation in­host health and well-be­ing.

There is grow­ing evid­ence that dis­persal among mi­cro­bi­o­mes isan im­port­ant driver of this vari­ation. To bet­ter un­der­stand how dis­persal in­ter­acts with oth­er­factors to de­term­ine the com­pos­i­tion of host-mi­cro­bi­o­mes, meta­com­munity the­ory has­re­cently been ap­plied to host-mi­cro­bi­o­mes. Meta­com­munity the­ory pos­its that the dy­nam­ic­swithin any local group of in­ter­act­ing spe­cies (a com­munity) are gov­erned both by pro­cessesthat oc­cur within the com­munity and by the pro­cess of dis­persal which links com­munit­i­esto­gether. The re­l­at­ive strengths of dis­persal and within-com­munity dy­nam­ics cre­ate dif­fer­ent­pat­terns of di­versity and spe­cies com­pos­i­tion across space and time.{ref­er­ence: Miller et al. 2018 TREE}.

Sum­mary: In my talk, I will present evid­ence for the hy­po­thesis that host-mi­cro­bi­o­mes act as­meta­com­munit­ies. I will then dis­cuss ex­amples of the eco­lo­gical im­plic­a­tions of thishy­po­thesis. I will fo­cus on the role of the en­vir­on­ment ex­ternal to hosts (the “mat­rix” in­meta­com­munity the­ory) as a me­di­ator of dis­persal, and how it can shape the eco­lo­gical trait­sof host-as­so­ci­ated mi­croor­gan­isms. I will end with a dis­cus­sion of the evol­u­tion­ary­im­plic­a­tions of host-mi­cro­bi­o­mes as meta­com­munit­ies, in­clud­ing re­cent the­ory re­gard­ing thecon­di­tions ne­ces­sary for co­e­volu­tion and how dis­persal among host-mi­cro­bi­o­mes may al­low“col­lect­ive in­her­it­ance” of mi­cro­bi­ome traits. {ref­er­ence: Miller & Bo­han­nan 2019 Fron­ti­ers in Eco­logy and Evol­u­tion}.