section_path: Academic research
section_name: Academic research
paragraph_text: Academic research
  
  Since Muslims could regard criticism of the Qur'an as a crime of apostasy punishable by death under sharia, it seemed impossible to conduct studies on the Qur'an that went beyond textual criticism. Until the early 1970s, non-Muslim scholars of Islam —while not accepting traditional explanations for divine intervention— accepted the above-mentioned traditional origin story in most details.
  
  University of Chicago professor Fred Donner states that:
  
  here was a very early attempt to establish a uniform consonantal text of the Qurʾān from what was probably a wider and more varied group of related texts in early transmission.… After the creation of this standardized canonical text, earlier authoritative texts were suppressed, and all extant manuscripts—despite their numerous variants —seem to date to a time after this standard consonantal text was established.
  
  Although most variant readings of the text of the Quran have ceased to be transmitted, some still are. There has been no critical text produced on which a scholarly reconstruction of the Quranic text could be based.
  
  In 1972, in a mosque in the city of Sana'a, Yemen, manuscripts "consisting of 12,000 pieces" were discovered that were later proven to be the oldest Quranic text known to exist at the time. The Sana'a manuscripts contain palimpsests, manuscript pages from which the text has been washed off to make the parchment reusable again—a practice which was common in ancient times due to the scarcity of writing material. However, the faint washed-off underlying text (scriptio inferior) is still barely visible. Studies using radiocarbon dating indicate that the parchments are dated to the period before 671 CE with a 99 percent probability. The German scholar Gerd R. Puin has been investigating these Quran fragments for years. His research team made 35,000 microfilm photographs of the manuscripts, which he dated to the early part of the 8th century. Puin has noted unconventional verse orderings, minor textual variations, and rare styles of orthography, and suggested that some of the parchments were palimpsests which had been reused. Puin believed that this implied an evolving text as opposed to a fixed one.
  
  In 2015, a single folio of a very early Quran, dating back to 1370 years earlier, was discovered in the library of the University of Birmingham, England. According to the tests carried out by the Oxford University Radiocarbon Accelerator Unit, "with a probability of more than 95%, the parchment was from between 568 and 645". The manuscript is written in Hijazi script, an early form of written Arabic. This possibly was one of the earliest extant exemplars of the Quran, but as the tests allow a range of possible dates, it cannot be said with certainty which of the existing versions is the oldest. Saudi scholar Saud al-Sarhan has expressed doubt over the age of the fragments as they contain dots and chapter separators that are believed to have originated later. The Birmingham manuscript caused excitement amongst believers because of its potential overlapping with the dominant tradition over the lifetime of Muhammad c. 570 to 632 CE and used as evidence to support conventional wisdom and to refute the revisionists' views that expresses findings and views different from the traditional approach to the early history of the Quran and Islam.