Six billion hungry carnivores to feed, by 2050.

And then we have a lower biomass of carnivores, and a lower biomass of top head, or the sharks, the large snappers, the large groupers.

But there's a very simple little kind of calculation of what's required, how much plants are required for the herbivores to live, how many herbivores for the carnivores to eat, etc., that you actually have to balance actively.

When our ancestors moved out of the African forest onto the savannah more than a million years ago, they rapidly became effective predators. Sharing prey with pre existing carnivores, they acquired tapeworms that originally inhabited only hyenas, large cats, and African hunting dogs.