Quote:


what selective advantage would a trex have for becoming a small chicken?



NITRO

I do hope you are joking
Even a little boy knows that the survival of the fittest must not be understood in terms of dimensions , claws and ferocity
If a Trex must eat a ton meat a day to survive while a chicken is happy with some seeds then a chicken can survive in certain enviromental conditions while the trex is bound to die