I am simply pointing out that human beings are not native to the Americas.   That is a hard fact that no one can deny.   All humans emigrated to the Americas.

15,000 years is a but a blink of the eye when it comes to history.   The Homo Sapiens species that all humans are a part of has been around for 200,000 years.  And I pointed out the fact that mammals have been living here for over 100 Million years, to again show how insignificant an amount of time humans have been living here.  

If you want to make a "We were here first argument", well, that is the exact same argument that is being used today against people now coming to our country.   Your attitude is basically no different than theirs.