 The Ramas were in some cases supplanted by the arrival of 21st century humans who are not only more intelligent, but more robust than the simple Ramas.They are still heavily used in farming, mining and other forms of unskilled manual labour, and occasionally still used as surrogate wombs for Tanu offspring as was originally done before humanity arrived.The author of the novels, Julian May, prefers the term 'metapsychic' to the terms 'psionic' or 'psychic', which she considers mundane and un-evocative thus 'Metapsychic' powers are psychic abilities by another name.