Further complicating matters was the fact, revealed as more genomes were sequenced and compared, that those bacteria captured early in eukaryotic cells—the ones that became mitochondria and chloroplasts—had themselves been recipients of horizontal gene transfer, from different kinds of bacteria, before their capture. This meant parts of genomes existed within other genomes before becoming parts of still other genomes, including yours. It was all a snarl. It was a mess. It was a plate of spaghetti. It was wonderful.
