The country gained full independence from France in 1960 in the wake of decolonization. Under the leadership of President Philibert Tsiranana, Madagascar's First Republic (1960–1972) was established as a democratic system modeled on that of France. This period was characterized by continued economic and cultural dependence upon France, provoking resentment and sparking the "rotaka", popular movements among farmers and students that ultimately ushered in the socialist Democratic Republic of Madagascar under Admiral Didier Ratsiraka (1975–1992) distinguished by economic isolationism and political alliances with pro-Soviet states. As Madagascar's economy quickly unraveled, standards of living declined dramatically and growing social unrest was increasingly met with violent repression on the part of the Ratsiraka government. By 1992, free and fair multiparty elections were held, ushering in the democratic Third Republic (1992–2009). Under the new constitution, the Malagasy public elected successive presidents Albert Zafy, Didier Ratsiraka, and Marc Ravalomanana. This latter was ousted in the 2009 Malagasy political crisis by a popular movement under the leadership of Andry Rajoelina, then-mayor of Antananarivo, in what was widely characterized as a coup d'état. Rajoelina ushered in the Malagasy constitutional referendum, 2010 and ruled Madagascar as president of the High Transitional Authority without recognition from the international community. Elections were held on December 20, 2013 to elect a new president and return the country to constitutional governance. The earliest unambiguous evidence of human presence in Madagascar was found at Andavakoera and dates to 490 CE. There is some evidence for earlier human presence, but it is ambiguous or not widely studied yet. Archaeological finds such as cut marks on bones found in the northwest and stone tools in the northeast indicate that Madagascar was visited by foragers around 2000 BCE. There is potential evidence in the form of a cutmarked subfossil lemur bone from a palaeontological site, Taolambiby, in the southwest. One date was obtained, calibrated 530 to 300 BCE (Godfrey & Jungers 2003). The cutmarking looks plausible, but there is a potential problem of old carbon from the limestone landscape compromising the date, and there are no associated artifacts or archaeological sites in the vicinity. Nearly contemporaneous potential evidence comes from cannabis or humulus pollen which occurs in a pollen column from the central highlands at an interpolated date of c. 2200 Before Present (BP). There is a hypothesis that cannabis may have reached Africa 3000 years ago.