I think you're right... I don't believe the whole genetics thing... if you feed a human good fatty foods for a year, they are going to get bigger! If you feed a normal sized person alot of protein and minerals they are going to get stronger. Why isn't it the same for deer?
...and on that day when my strength is failing, the end draws near and my times has come, still my soul will sing Your praise unending, ten thousand years and then forevermore!