The Gene Meme installation was accompanied by a public debate about the controversial subject of population growth. It is seen by some as a non-issue, a Malthusian theory that is a failed prophesy of doom, whilst others see it as a disruptive problem that makes all other problems worse, and suggesting that when women are given choice in their lives, they naturally have fewer children.

The well-attended debate in St Pancras Church was chaired by the BBC's Geoff Watts, who observed the history of life on the planet shows a repeating pattern of population growth followed by collapse. Are we at the point where our own species has made itself unsustainable and faces a crash? If so, what can or should we do about it? Six eminent speakers, including zoologist and broadcaster Aubrey Manning, and Fred Pearce from the Guardian, offered a range of views. Some thought the marked decline in the global fertility rate over the past 40 years was defusing the issue; others pointed out that even such a steep decline would slow overall growth only gradually, and suggested that action would be needed to bring about the stabilisation that most agreed was necessary. In the course of a lively debate, all agreed that we could not continue to live as we are doing, and that failure to address the issues could only mean that future generations would find themselves in an increasingly hostile environment of our making.