There is yet no consensus as to which of these groups should be considered a separate species .
Which should be a subspecies ; this may be due to the dearth of fossils or to the slight differences used to classify species in the genus Homo .
There is yet no consensus as to which of these groups should be considered a separate species and which should be a subspecies ; this may be due to the dearth of fossils or to the slight differences used to classify species in the genus Homo .