“But the mutation is not dangerous to humans”
in fact, it is precisely the virus genetic mutation (or more precisely re-assortment) in animals which allow its transmission to humans.
From SARS coronavirus to novel animal and human coronaviruses
Kelvin K. W. To,1,2 Ivan F. N. Hung,1,3 Jasper F. W. Chan,1,2 and Kwok-Yung Yuencorresponding author1,2
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3747523/
In 2003, severe acute respiratory syndrome coronavirus (SARS-CoV) caused one of the most devastating epidemics known to the developed world. There were two important lessons from this epidemic. Firstly, coronaviruses, in addition to influenza viruses, can cause severe and rapidly spreading human infections. Secondly, bats can serve as the origin and natural animal reservoir of deadly human viruses. Since then, researchers around the world, especially those in Asia where SARS-CoV was first identified, have turned their focus to find novel coronaviruses infecting humans, bats, and other animals. Two human coronaviruses, HCoV-HKU1 and HCoV-NL63, were identified shortly after the SARS-CoV epidemic as common causes of human respiratory tract infections. In 2012, a novel human coronavirus, now called Middle East respiratory syndrome coronavirus (MERS-CoV), has emerged in the Middle East to cause fatal human infections in three continents.
actually, the other human viruses that are Ebola like or have some of the same structural attributes, are viruses like measles.
According to what I have read in some science journals, Ebola has a difficult time mutating. It's mutations must fit within the enclosure that Ebola has. Thus it is limited to those mutations that do.
For this reason and other reasons that affect it's ability to spread among humans, it has stayed in West Africa since we discovered it in 1976.