by Christoph — For evo­lu­tion­ary bi­ol­o­gists, the aphid·Buchnera sym­bio­sis is a fa­vorite model to study 'or­ga­nel­lo­ge­ne­sis', how a once free-liv­ing gammapro­teobac­terium be­came an oblig­a­tory en­dosym­biont of its aphid host – now its buddy rather – over the course of >200 Ma (mil­lion years) of co-evo­lu­tion. Today's...