symbolic numerology: '2' was related to origins, as all origins can be thought of as doubling; '3' was related to household fire; '4' was linked to the four corners of the universe; '5' expressed instability; '9' pertained to the underworld and the night; '13' was the number for light, '20' for abundance, and '400' for infinity. The concept of zero was also used, and its representation at the Late Preclassic occupation of Tres Zapotes is one of the earliest uses of zero in human history. Food, medicine, and science Maize played an important role in Mesoamerican feasts due to its symbolic meaning and abundance. Gods were praised and named after. Companion planting was practiced in various forms by the indigenous peoples of the Americas. They domesticated squash 8,000 to 10,000 years ago, then maize, then common beans, forming the Three Sisters agricultural technique. The cornstalk served as a trellis for the beans to climb, and the beans fixed nitrogen, benefitting the maize. Fray Bernardino de Sahagún collected extensive information on plants, animals, soil types, among other matters from native informants in Book 11, The Earthly Things, of the twelve-volume General History of the Things of New Spain, known as the Florentine Codex, compiled in the third quarter of the sixteenth century. Bernardino de Sahagún reported the ritualistic use of Psilocybe mushrooms known to the Aztecs as teōnanācatl (agglutinative form of teōtl (god, sacred) and nanācatl (mushroom) in Náhuatl). An earlier work, the Badianus Manuscript or Libellus de Medicinalibus Indorum Herbis is another Aztec codex with written text and illustrations collected from the indigenous viewpoint. The ancient Aztecs used a variety of entheogens within their society. Evidence shows that wild animals were captured and traded for symbolic and ritual purposes. Mythology and worldview Shared traits in Mesoamerican mythology are characterized by their common basis as a religion that—though in many Mesoamerican groups developed into complex polytheistic religious systems—retained some shamanistic elements. The great breadth of the Mesoamerican pantheon of deities is due to the incorporation of ideological and religious elements from the first primitive religion of Fire, Earth, Water and Nature. Astral divinities (the sun, stars, constellations, and Venus) were adopted and represented in anthropomorphic, zoomorphic, and anthropozoomorphic sculptures, and in day-to-day objects. The qualities of these gods and their attributes changed with the passage of time and with cultural influences from other Mesoamerican groups. The gods are at once three: