The early hymns of the Rug Veda are very much concerned with nature the sun, the dawn and the milk-giving cow, for example. Religion seems to have been mainly propitiation of the deities to ensure a good, long life followed by a life in the World of the Fathers, the Vedic Heaven. Here, Yama, the first mortal to die, was guardian and welcomed those who had led a good life and who had not offended the gods, particularly the god of the cosmic order, Varuna. Conversely, the wicked would be condemned to the ' House of Clay ', the Vedic hell. It is interesting to note that, despite the development of key concepts of karma and samsara later in Hindu tradition, these Aryan ideas of heaven and hell were accommodated alongside and not simply replaced. If there was a concern for nature in Vedic religion, this did not extend to fertility in the sense of emphasizing the principle of a Mother Goddess, and the Aryans were certainly critical of the indigenous people as ' those who worship the phallus '. Their deities were mainly male, reflecting the patriarchal character of nomadic and herd-rearing people in general. This is not to say that female deities were entirely absent. In particular, there was a ' mother ' of the gods, Aditi, who gave birth to a group of seven or eight gods known as the Adityas, but Aditi is not important in the Vedas. Usas, the goddess of dawn, was probably the most prominent, and there are a number of very beautiful hymns in which she is featured but, to quote Heesterman, female deities ' remain diffuse, lacking in profile and to a high degree interchangeable with one another '. Female divinities were thus minimal, they personified aspects of nature as wives of the gods but were not goddesses in their own right. There is, however, some evidence of the female consorts of the gods being an emanation of their power and energy - sakti - in the early Vedic material. This may prefigure the kind of conception of sakti which is evident in later Hinduism. And in the Atharva Veda female deities are much more numerous, though no goddess rises to independent status in Vedic religion.