Population geneticists have debated whether the concept of population can provide a basis for a new conception of race. In order to do this, a working definition of population must be found. Surprisingly, there is no generally accepted concept of population that biologists use. Although the concept of population is central to ecology, evolutionary biology and conservation biology, most definitions of population rely on qualitative descriptions such as "a group of organisms of the same species occupying a particular space at a particular time" Waples and Gaggiotti identify two broad types of definitions for populations; those that fall into an ecological paradigm, and those that fall into an evolutionary paradigm. Examples of such definitions are: