"no math" could colonize islands separated by vast distances of ocean water, even against prevailing winds and currents. He rejected the highly skilled voyaging and navigating traditions of the Austronesian peoples and instead argued that Polynesia was settled from boats following the wind and currents for navigation from South America. As such, the Kon-Tiki was deliberately a primitive raft and unsteerable, in contrast to the sophisticated outrigger canoes and catamarans of the Austronesian people. Heyerdahl's hypothesis of Polynesian origins is overwhelmingly rejected by scientists today. Archaeological, linguistic, cultural, and genetic evidence all support a western origin (from Island Southeast Asia) for Polynesians via the Austronesian expansion. "Drift voyaging" from South America was also deemed "extremely unlikely" in 1973 by computer modeling, although is in contrast with recent genetic analysis. The 1976 voyage of the Hōkūleʻa, a performance-accurate replica of a Polynesian double-hulled wa'a kaulua voyaging canoe, from Hawaiʻi to Tahiti was partly a demonstration to prove that Heyerdahl was wrong. The Hōkūleʻa sailed against prevailing winds and exclusively used wayfinding and celestial Polynesian navigation techniques (unlike the modern equipment and charts of the Kon-Tiki). Hōkūleʻa also remains fully operational, and has since completed ten other voyages, including a three-year circumnavigation of the planet from 2014 to 2017, with other sister ships. Historians today consider that the Polynesians from the west were the original inhabitants and that the story of the Hanau epe is either pure myth, or a memory of internal tribal or class conflicts. In 2011, Erik Thorsby of the University of Oslo presented DNA evidence to the Royal Society which, whilst agreeing with the west origin, also identified a distinctive but smaller genetic contribution from South America. This result was questioned in 2012 because of the possibility of contamination by South Americans after European contact with the islands. In 2014, further work by a team including Anna-Sapfo Malaspinas (from the Natural History Museum of Denmark) analysed the genomes of 27 native Rapa Nui people and found that their DNA was on average 76 percent Polynesian, 8 percent Native American and 16 percent European. Analysis showed that "although the European lineage could be explained by contact with white Europeans after the island was 'discovered' in 1722 by Dutch sailors, the South American component was much older, dating to between about 1280 and 1495, soon after the island was first colonised by Polynesians in around 1200." Genetic analysis of Polynesians