“How do you know if the ancestor of modern humans had fur?”
Are you being serious with this question?
“..... this is for all them smartass folk saying we come descended from monkeys!”
from Oh Brother where art thou.
Are you being serious with this question?
Yes. there are a lot of competing ideas on evolution. Physical evidence is scarce. Sorting out the different beliefs is a real challenge. Making strong assertions in evolution is reckless. The creationists and ancient alien theorists make strong assertions based on no physical evidence but rather on ancient testimony and myths.