The ancestral apes already had large and high-quality brains.They had good eyes and efficient grasping hands.They inevitably had some degree of social organization.With strong pressure on them to increase their preykilling power,vital changes began to take place.They became more upright,and were faster,better runners.Their hands became strong,efficient weapon holders.Their brains became more complex,and developed into brighter,quicker decision-makers.But there developments did not follow one another in a major,set sequence;minute advances being made first in one quality and then in another,each urged the other on.A hunting ape,a killer ape,was in the making.