Recently, I have discovered that natural selection act differently on two copies of duplicates.
My lab study evolutionary genomics, with fruit fly as our model animal. There’re a lot a gene duplicates in fruit fly, which means a lot a genes copied themselves several million years ago. Since the two copies are identical, you would imagine that selection work the same way on either copy. However, my research found that the younger copy is more like to be under positive selection and get preserved in the genome.
I think this is pretty cool : ) I will figure out why this is the case in the follow up research.