The other major influence was the Gaia hypothesis, that the Earth is a single living system that self-regulates to maintain the optimum conditions for life, formulated by climate scientist James Lovelock and popularised in his 1979 book "Gaia: A new look at life on Earth". Kennedy Martin used the name GAIA for the environmental organisation Emma Craven was involved in and drew the notion for the black flowers seen at the serial's conclusion from a passage in Lovelock's book that describes a dark marsh grass that grew on the surface of the Earth trapping heat during a time when the planet was too cold to sustain life, simulated in Lovelock's Daisyworld model.