The separation of the sexes occurred only during the Lemurian time. Therewith the first incarnations were possible, the taking over of a body which hadn’t already existed. Previously one being derived from another. With the separation of the sexes during the middle of the Lemurian age, birth and death arose and therefore the possibility of the effects of karma. The human being could burden himself with guilt. Everything we know as “human” arose at that time.
Source: Rudolf Steiner – GA 89 – Theosophic/Esoteric Cosmology: Esoteric Cosmology: 3 – Berlin, 9th June, 1904
Translation: Frank Thomas Smith