Stag beetle Cyclommatus metallifer SE Asia : Males with larger mandibles outcompete males with smaller mandibles have greater access to females . This has driven the evolution of increasingly larger, more elaborate mandibles.
Building Muscles After For some reasons, an average person has more natural muscle mass on his/her body when he/she is younger than when he/she gets older. Muscular natural development process progresses slower as we age. It does not mean that an indi