I have a question in mind and would like to gain insights from biostars members.
As the title, for example, if we compare human and a bacteria, generally we will accept a bacteria is 'less evolved' or 'more ancient' or 'more primitive' than human.
Then now I have two bacteria, how could we compare the extent of evolution between the two bacteria species?
And after more thought, I have some more questions:
1) What is the actual evidence for us to put forward 'bacteria is less evolved than human' apart from just stating the concept of evolution that we think more complex species are originated from less complex species?
2) Is it technically impossible to distinguish the extent of evolution if two species are too closely related?
3) Then following question 2), what is our 'best resolution' to compare the extent of evolution between any two species?
I look forward to your reply.