This question is not clear, but I think I understand what you are asking. The difference between alleles of a gene is that some alleles may be dominant or recessive. If one gene has more dominant alleles than another, than it will be more visible.
The eons that make up 90% of Earth's history are the Precambrian eons, which consists of Hadean, Archean, and Proterozoic eons.
Science is a investigation process
secondary succesion takes place
