Internal users will require a CAL which is about $100 per user. A forecast of the number of users will be used for Capacity planning for your SharePoint farm. Each server will require a server license. So the number of users may increase the cost of the server licensing.
Another example of convergent evolution is the overall body structure of the shark and the dolphin. A shark is a fish and a dolphin is a mammal. However, their body shape and how they move through the ocean is very similar.
Co-evolution is where the existence of one species is tightly bound up with the life of one or more other species. Species whose lives connect, evolve together. What happens is that survival rates in each species changes as a result of changes in the other species. Examples of co-evolution are: Species which mutually benefit