In Ascension

by Martin MacInnes

‘Very generous of you. I’m trying to show how important the transition is, from prokaryote to eukaryote. A fluke event, interrupting what would have been endless repetition. So it makes sense, surely, that we should find out everything we can about it, about what exactly happened back then – right?’ ‘And you think the archaea from Endeavour can help?’ ‘Why not? So the theory is archaea and bacteria started to help each other.’ ‘Symbiosis.’ ‘Exactly. Which is actually much more prominent in evolution than most people admit. Which is interesting politically. Bacteria still sometimes live inside each other; they’re really strange. They borrow genes from each other all the time, wildly different species. There’s a theory that all bacteria constitute a single, massively distributed organism – a single individual, even . . . Anyway, so we think an archaeal cell and a bacterial cell formed a close chemical dependency, and – we can’t say how this happened; this is the miracle – the two cells fused, became a single, chimerical identity. An archaea cell with parts of a bacterial cell inside it. And this thing endured, because it was useful, it was helpful, it was easier to live this way. So the bacterial parts get repurposed inside the bigger cell, energy production changes, a ferocious, runaway complexity emerges, and eventually you have a nucleus.