有植物先定動物先~???

prokaryotes existed first, but if you want to compare animals and plants, i would say animals existed first, because as you know, animal cells don't have cell walls but plant cells have. cell walls are formed by cellulose, a complex compound. In the develpoment of living things, it should be simple----> complex, so animal cells should have occured first.

2010-09-21 20:47:07 補充：
but beware that my answer is just a guess, because in my point of view, that is sth that no one knows, I only answer that with my biological sense, i can't think of any facts about the comparison of the priority of existence between them. sry.

http://zh.wikipedia.org/zh/%E7%94%9F%E5%91%BD%E6%BC%94%E5%8C%96%E5%8E%86%E7%A8%8B