Looks like we understand a little better how to optimize our biology, check out this article on mice that are basically Lance Armstrong on crack:
The mice over-express a gene responsible for the enzyme phosphoenolypyruvate carboxykinases (PEPCK-C). Normal expression is in the liver, in the production of glucose.
The scientists found their new mice would eat twice as much as normal mice – but weigh half as much. They could also give birth at three years old – which in human terms is akin to an 80-year-old woman giving birth.
via BBC NEWS