SENIOR police officers have been told to explain why they prevented rival gangs of West Ham and Millwall fans from beating from each other to death last night.
As violence flared at Upton Park, zoologists said riot police had no right to interfere with the natural process of evolution.
Experts have called for new guidelines that will allow football supporters to bang each other's skulls with baseball bats until the last retard standing finally clubs himself into oblivion.
Dr Tom Logan, of the Institute for Studies, said: "A full-on riot between West Ham and Millwall fans is a bit like Mother Nature's pruning shears.
"We do not intervene when a pride of lions takes down an antelope, or when rival baboons fight over who gets the biggest nuts.
"So when two sets of London football fans decide to have a fight, we should simply leave them be, while observing the awesome majesty of Darwin's genius."
It is believed the violence flared between the rival supporters after an argument over who would be the first to grow opposable thumbs.
West Ham fan, Wayne Hayes, said: "They was sayin' that one of 'em already 'ad fums and could use tools and evryfin'.
"And I was like, 'you fackin' bastards, my old dad nearly 'ad fums once, you callin' me a cant?'."
But Millwall fan, Nathan Muir, pointed frantically at a piece of wood, insisting: "Ee-ee! Ee-ee-ah-ah-oo-oo! Eeeeee! Eeeeee! Eeeeeeeee!"