People
The system of life on this planet is so astoundingly complex that it was a long time before man even realised that it was a system at all and that it wasn’t something that was just there.
— Douglas Adams ‧ Last Chance To See

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
The passage presents life's complexity as something people were slow to recognise as a system. It contrasts connected organisation with the assumption that things were simply there. The surprising emphasis falls on perception: recognising a pattern is itself portrayed as a difficult and belated achievement.
Context reviewed