" didn’t,’ Morris said casually. ‘It was obviously seeded.’ Malenfant frowned. ‘By what? A comet impact or such?’ ‘Oh, no. By whoever seeded Persephone also. The amino acid suites are identical – that alone is enough to rule out chance parallel evolutions.’ ‘You said – whoever?’ ‘And whoever seeded Earth too.’ Morris glanced around. ‘Come on! I think we’re being left behind.’ He hurried off along the track, over the glistening, bug-ridden ice. Deirdra stared at Malenfant. ‘Did he really say that? That somebody, or something, seeded "

― Stephen Baxter , World Engines: Destroyer