However, in the 20th century, scholars such as Richard Garbe suggested that the pre-Upanishad Vedic tradition may not have had a monastic tradition, and that the Upanishads, Jainism and Buddhism may have been new movements that grew, partly in opposition, on the foundations and ideas of earlier Vedic practices. The asceticism and monastic practices possibly emerged in India in the early centuries of the 1st millennium BCE. Johannes Bronkhorst has proposed a dual model, wherein monastic traditions and matha began in parallel, both in Vedic and non-Vedic streams of traditions, citing evidence from ancient Hindu Dharmasutras dated to have been composed between 500 BCE to about the start of the common era. Other evidence of "mathas" is found in the Brahmanas layer of the Vedic texts, such as in chapter 10.6 of Shatapatha Brahmana (Yajurveda) as well as in the surviving Aranyaka layer of the Vedas such as in chapter 15 of Shankhayana Aranyaka.