Evolution: Climate—hereafter simply referred to as Evolution—presents itself as a bucolic game. I start by creating some adorable new species with tiny body sizes and low populations. The climate is temperate, the food abundant, the predators rare. My furry little rascals satiate themselves with the plentiful food beside the watering hole. “Nature red in tooth in claw?” Not here.

But the abundance of food encourages huge population growth—and not just among my species, but all around the table. The vegetarian options available from the watering hole just barely feed every creature. And then the climate changes; a cold snap puts pressure not just on the food supply, but on all species with small body sizes.