No need to shrink guts to have a larger brain

Have you ever wonder why no other animals have a large brain? Well there is a theory that is called the expensive tissue hypothesis which suggests the trade off of the size of the brain and the and the size of digestion origins. Although now that theory is being challenged. Scientist have seen animals that their brains grew but not their organs. One example is us we grew larger brains but our size didn't change, this is because of the ability of waling upright and diet. As we all know the brain takes up lots of our energy that we could use for other things, like animals do. We know that if an animals brain stays small that is why they need more food or resources so they used their energy for moving or climbing trees instead of expanding the brain. Another interesting theory is that the more fat an animal has the smaller brain but fat doesn't waste our energy. Well it dose when we move and that is when it wastes our energy on walking more then brain expansion."It seems that large adipose deposits often come at the expense of mental flexibility," says Karin Isler. Our bypedalism doesn't waste much energy and that why we grew larger brains.