Around 12,500 BC, the Würm Glacial Age ended. Slowly, through the following millennia, temperatures and sea levels rose, changing the environment of prehistoric people. Ireland and Great Britain become islands, and Scandinavia became separated from the main part of the European Peninsula. (They had all once been connected by a now-submerged region of the continental shelf known as Doggerland.) Nevertheless, the Magdalenian culture persisted until 10,000 BC, when it quickly evolved into two "microlithist" cultures: Azilian, in Spain and southern France, and Sauveterrian, in northern France and Central Europe. Despite some differences, both cultures shared several traits: the creation of very small stone tools called microliths and the scarcity of figurative art, which seems to have vanished almost completely, which was replaced by abstract decoration of tools.