Persons or animals dive or otherwise decend to the lower world to get a desired object and to bring it to earth (besides episodes in the fairytales, cf. motif k27x9)
The dry land (the earth) grows from a small amount of solid substance (sand, clay, dirt and the like) brought from the lower world (usually from the bottom of the ocean)
The first people (or only the first men or the first women) are not created but come to earth from the underworld (from a cave) or from a small enclosure under the earth or on its surface (tree trunk, rock, gourd, etc.). Many people of both sexes and of different ages or people and different species of animals come out together