The function of the hormone oxytocin in the progression of labor is to induce contractions. The contractions then produce more oxytocin, which creates more contractions, thereby functioning as a positive feedback mechanism.
The cells become differentiated and organised into groups or tissues
This is the First Law of Thermodynamics. It's also called the Law of Conservation of Energy.
They are based in the laws of Probability
Say the food is squirrels and the predator is hawks, the result of there being a surplus of squirrels would cause an overpopulation of squirrels.