Biology is a hard field for Chinese to get professorship, probably because the requirement to have substantial grant support. Due to language, culture, and lack of training in writing, few Chinese students know how to write a good proposal right after getting Ph.D. When they finally learn enough lessons, it may be too late.

It appears that Mathematicians get the easiest path to professorship. They don't need grant at all to do research. Or, they don't even have to do a lot of research if they don't go to top universities. Easy life, isn't it.