Its really odd how speices shunk, from the dinos that turned into birds, while our speice from the lumurs got bigger, what would have cause it? http://news.discover...#mkcpgn=rssnws1
Your OP covers two different topics. It's best not to do that as it only causes confusion. Seeing as the penguin link has already been posted, I've changed the topic heading to cover the bird link.
Climate maybe, but from what I understand evolution was from the adaption to the environment. But what kind of environment would make a speice bigger or smaller?