No," Morrow said. "I can't accept that. I don't always agree with the Planners. But they aren't killers." "You think not?" Uvarov laughed again. "The… - Stephen Baxter

A lion takes only the last deer in the herd. She does not dream of having so many cubs that the plains would be full of nothing but lions. There are simple laws. Most species figure them out; you are the exception. An ecology of a single species is not viable. A diverse, stable world would provide for you.

On the longest of timescales, over millions of years, the workings of chance defied human intuition. Humans were equipped with a subjective consciousness of risk and improbability suitable for creatures with a lifespan of less than a century or so. Event that came much less frequently than that—such as asteroid impacts—were place, in human minds, in the category not of rare, but of never. But the impacts happened even so, and to a creature with a lifespan of, say, ten million years, would not have seemed so improbable at all.
Given enough time even such unlikely events as ocean crossings from Africa to South America would inevitably occur, over and again, and would shape the destiny of life.

“So that’s that,” Miriam said. “We have a plan.”
“You have a shared delusion,” I said.