IN: The Mississippian culture was a mound-building Native American civilization archeologists date from approximately 800 CE to 1600 CE, varying regionally. It was composed of a series of urban settlements and satellite villages (suburbs) linked together by a loose trading network, the largest city being Cahokia, believed to be a major religious center. The civilization flourished from the southern shores of the Great Lakes at Western New York and Western Pennsylvania in what is now the Eastern Midwest, extending south-southwest into the lower Mississippi Valley and wrapping easterly around the southern foot of the Appalachians barrier range into what is now the Southeastern United States. The Mississippian way of life began to develop in the Mississippi River Valley (for which it is named).

The Mississippi stage is usually divided into three or more chronological periods. Each period is an arbitrary historical distinction varying regionally. At a particular site, each period may be considered to begin earlier or later, depending on the speed of adoption or development of given Mississippian traits. The "Mississippi period" should not be confused with the "Mississippian culture". The Mississippi period is the chronological stage, while Mississippian culture refers to the cultural similarities that characterize this society. The Early Mississippi period (c. 1000-1200 CE) had just transitioned from the Late Woodland period way of life (500-1000). Different groups abandoned tribal lifeways for increasing complexity, sedentism, centralization, and agriculture. Production of surplus corn and attractions of the regional chiefdoms led to rapid population concentrations in major centers. The Middle Mississippi period (c. 1200-1400) is the apex of the Mississippi era. The expansion of the great metropolis and ceremonial complex at Cahokia (in present-day Illinois), the formation of other complex chiefdoms, and the spread and development of SECC art and symbolism are characteristic changes of this period. The Mississippian traits listed above came to be widespread throughout the region. The Late Mississippi period (c. 1400-1540) is characterized by increasing warfare, political turmoil, and population movement. The population of Cahokia dispersed early in this period (1350-1400), perhaps migrating to other rising political centers. More defensive structures are often seen at sites, and sometimes a decline in mound-building and large scale, public ceremonialism. Although some areas continued an essentially Middle Mississippian culture until the first significant contact with Europeans, the population of most areas had dispersed or were experiencing severe social stress by 1500. Along with the contemporaneous Ancestral Pueblo peoples, these cultural collapses coincide with the global climate change of the Little Ice Age. Scholars theorize drought and the reduction of maize agriculture, together with possible deforestation and overhunting by the concentrated populations, forced them to move away from major sites. This period ended with European contact in the 16th century.
QUESTION: transitioned to what?
IN: No Doubt is an American ska band from Anaheim, California, that formed in 1986. Since 1994, the group has consisted of vocalist Gwen Stefani, bassist and keyboardist Tony Kanal, guitarist and keyboardist Tom Dumont, and drummer Adrian Young. Since the mid-1990s in live performances and the studio, they have been supported by keyboardist and trombonist Gabrial McNair and keyboardist and trumpeter Stephen Bradley. The ska sound of their song, "Trapped in a Box" (1992), that was featured on their first album

Eric Stefani and John Spence met at a Dairy Queen and had talked about getting a group together to play music. Eric got a keyboard and gathered some players together to practice. The practice included Eric Stefani (keyboards), Gwen Stefani (backing vocals), John Spence (lead vocals), Jerry McMahon (guitar), Chris Leal (bass), Chris Webb (drums), Gabriel Gonzalez & Alan Meade (trumpet) and Tony Meade (saxophone). They practiced in Eric's parents' garage. Tony Kanal went to one of the band's early shows and soon joined the band as its bassist. After initially rejecting her advances, he began dating Gwen, but they kept their relationship secret for a year, feeling that it was an unspoken rule that no one in the band dates her. Paul Caseley (trombone) also joined the band in 1987. Eric Carpenter (saxophone) joined the horn section soon after. In December 1987, Spence committed suicide several days before the band was to play a gig at The Roxy Theatre for record industry employees. No Doubt disbanded but decided to regroup after several weeks with Alan Meade taking over vocals. When Meade left the band, Gwen replaced him as lead singer, and No Doubt continued to develop a live following in California. In early 1988, Tom Dumont left Rising, a heavy metal band of which he was a member with his sister, stating that local metal bands "were into drinking, wearing Spandex" but that he wanted to focus on music. He joined No Doubt and replaced Jerry McMahon as the band's guitarist. Adrian Young replaced Chris Webb as the drummer the following year. During this time period, No Doubt played gigs at local colleges, Fender's Grand Ballroom, The Whisky, The Roxy, many shows with The Untouchables, Fishbone, and a show with the Red Hot Chili Peppers at Cal State Long Beach. Caseley left No Doubt in July 1989 for the US Navy Band.
QUESTION:
what happened in 1985?