In some myths, an asexual mode of creation is implied; a child, for example, appears from the bud of a tree or from a split fruit, or a human being is a featherless bird sent from the sky. Even the motif of human birth from an egg is predominantly an asexual motif inasmuch as no preliminary coition is mentioned. Other traditions, particularly agricultural ones, see humans as the product of the mating of a plant or animal species. In some myths, fabrication rather than descent is emphasized. Humans are fashioned from a plant or animal by the gods, or their parts are modeled after other species. In these descent traditions, the human who results is usually the progenitor of a particular people. Other peoples are created from different or less favourable species. These traditions persist in folkloric accounts of the birth of individuals from plants or animals. Such myths express a close relationship between humans and the animal and plant world. Humans do not represent a new type of being but rather a new manifestation or form.
The widely distributed notion of animal or plant ancestors places considerable emphasis on transformation (see below Relationships of transformation). The ancestral myths describe a primeval time of creation (or successive creations) followed by a decisive alteration in the conditions of life in the shift from the ancestral to the present human mode of being. Compared with the “fixed” characteristics of the present period, the ancestral era is represented as having been one of flux, lacking definite boundaries. In it animals, plants, and humans are much the same: they can speak with each other, have sexual relations with each other, and engage in other relationships. The ancestors are polymorphic (many formed) and are frequently depicted as emerging from the ground. In such cases their movement toward the surface is represented as an increasing differentiation, away from compound hybrids and toward forms somewhat resembling present species. But even on the surface, the ancestors remain relatively fluid: some resemble plants, others animals or humans, and all have shared characteristics and the power to change their form at will.