In a "New York Times" 1977 review of Van Sertima's 1976 book "They Came Before Columbus", the archaeologist Glyn Daniel labelled Van Sertima's work as "ignorant rubbish", and concluded that the works of Van Sertima, and Barry Fell, whom he was also reviewing, "give us badly argued theories based on fantasies". In response to Daniel's review Clarence Weiant, who had worked as an assistant archaeologist specialising in ceramics at Tres Zapotes and later pursued a career as a chiropractor, wrote a letter to the "New York Times" supporting Van Sertima's work. Weiant wrote: "Van Sertima's work is a summary of six or seven years of meticulous research based upon archaeology, egyptology, African history, oceanography, astronomy, botany, rare Arabic and Chinese manuscripts, the letters and journals of early American explorers, and the observations of physical anthropologists... As one who has been immersed in Mexican archaeology for some forty years, and who participated in the excavation of the first giant heads, I must confess, I am thoroughly convinced of the soundness of Van Sertima's conclusions."