I am talking about changing the shape of an individual muscle group.
no way, no how. it's never been done, unless we're talking tweaking the shape via inflamation/oil/surgery or some means whereby on part of a muscle's length is altered.
compare peak sergio's, arnold's and al beckles right biceps.
all are fully developed (or near), but each have a completely different shape. sergio's is long and flat, beckles is short and very peaked and arnold's is full and peaked.
all 3 of these guys trained in a very similar fashion ie same type of exercises.
actually, on this note, the best example would be to compare franco and arnold.
now, bearing in mind that these guys were training partners for a very long time and trained in exactly the same way, arnold had full, peaked and long bis whereas franco had very short and not so peaked bis.
arnold did exactly the same workout for both of his bis, yet one (right) was far more peaked than the other. great example because two differently shaped bis exist on the same body.