Table 2. Hypothesized HGT events of phototrophy modules.

Enzymes	Donor Organism	Recipient Organism	Notes
RC2	Ghost Lineage	Proteobacteria
RC2/PSII	Ghost Lineage	Cyanobacteria	Followed by change of function from RC2 to PSII
BchXYZ	Ghost Lineage	Proteobacteria	Followed by change of function
BchXYZ	Proteobacteria	Chloroflexi+Chlorobi+WPS2
RC2	Proteobacteria	Chloroflexi+Chlorobi+WPS2	Associated with loss of RC1
BchXYZ	Chloroflexi+Chlorobi	Chloracidobacteria
RC1	Chloracidobacteria	Chlorobi	Associated with loss of RC2 in Chlorobi
BchXYZ	Chloracidobacteria	Heliobacteria