The initial charge, however, is wrong ~ genocide simply was not conducted against the Indians. For a variety of reasons vast plagues swept through native populations in the Western hemisphere and tens, even hundreds, of millions of people died.
Traditionaly Western diseases have been blamed for these deaths, but more recent findings by authoritative and competent scientific investigators have revealed that the plagues were probably hanta virus of various kinds.
There are gazillions of reference works on the matter ~ yet they remain unread.
The death rate among the California mission Indians during the mission era (1769-1834) was about 90%.
And, there is increasing evidence that introduced diseases had already significantly lowered populations by the time Spanish colonization began.