seat are related at all. Only a small percentage of Koreans had surnames and ancestral seats to begin with, and that the rest of the Korean population had adopted these surname and ancestral seat identities within the last two to three hundred years. Culture North Korea and South Korea share a common heritage, but the political division since 1945 has resulted in some divergence of their modern cultures. Language The language of the Korean people is the Korean language, which uses Hangul as its main writing system. Daily usage of Hanja has been phased out in Korean peninsula other than usage by selected South Korean media companies (mostly conservative) when referring to key politicians (e.g. current and former Presidents, leaders of major political parties) or handful of countries (e.g. China, Japan, US, UK) as an abbreviation. Otherwise, Hanja is exclusively used for academic, historical and religious purposes. Roman alphabet is the de facto secondary writing system in South Korea especially for loan words and is widely used in day-to-day and official communication. There are more than 78 million speakers of the Korean language worldwide. The difference in speech between North and South Korea stem from already pre-existing dialects instead of a supposed post-war divergence. Demographics Large-scale emigration from Korea began as early as the mid-1860s, mainly into the Russian Far East and Northeast China (also historically known by the exonym Manchuria); these populations would later grow to more than two million Koreans in China and several hundred thousand Koryo-saram (ethnic Koreans in Central Asia and the former USSR). During the Korea under Japanese rule of 1910–1945, Koreans were often recruited and or forced into labour service to work in mainland Japan, Karafuto Prefecture (Sakhalin), and Manchukuo; the ones who chose to remain in Japan at the end of the war became known as Zainichi Koreans, while the roughly 40,000 Koreans who were trapped in Karafuto after the Soviet invasion are typically referred to as Sakhalin Koreans. South Korea In June 2012, South Korea's population reached 50 million and by the end of 2016, South Korea's population has surpassed 51 million people. Since the 2000s, South Korea has been struggling with a low birthrate, leading some researchers to suggest that if current population trends hold, the country's population will shrink to approximately 38 million population towards the end of the 21st century. In 2018, fertility in South Korea became again a