Behold the original evolutionary hookup story! First, lonely cyanobacteria discovers its true love - photosynthesis. Then, in the ultimate friends-with-benefits scenario, eukaryotic cells slide into the DMs like "hey cutie, wanna move in together?" Next thing you know, cyanobacteria gets completely absorbed and becomes chloroplasts. Talk about a committed relationship! This is literally how plants happened - one microbe ate another and instead of digesting it thought "you know what, I like your energy production skills, let's make this permanent." Evolution's version of "it's not a phase, mom!"