“We’ve known about the gram-negative bacteria for three scientific generations. We’ve been staring at them for a hundred years, and we never realized how they came about or what made them so different,” said Lake. “Without them, we wouldn’t have eukaryotes as we do today.”According to Lake, the union likely took the form of endosymbiosis, in which one of the prokaryotes literally swallowed the other, and the two grew together.


Were mammals derived from a union of insect and amphibian, the story-of-life rearrangement would be comparably profound.