Alternative speculations
Some members of the Church of Jesus Christ of Latter Day Saints (Mormons) have suggested that the Olmecs may be the Jaredites recorded in the Book of Mormon because of alleged similarities in the Olmec archaeological record. However, the book mentions things that are known not to have been part of the Olmec culture, such as iron, silk and elephants. This speculation is not supported by any aspect of conventional Mesoamerican scholarship.
Others have pointed to the full lips and broad noses of Olmec monuments as evidence that Olmec ancestry may trace back to west Africa, but virtually all mainstream Mesoamerican scholars reject this and point out the central role of the "were-jaguar", half man, half cat, in early Mesoamerican religions. Moreover, they point out that not all people with broad noses and full lips are African, and some Native Americans of the region still display these traits today without any ancestral evidence for any of these possible lineages. Full lips and short broad noses are the norm among Mesoamericans and tropical peoples generally. It is also noted that the colossal Olmec monuments show eye folds found in the local Mesoamericans, a trait unknown among the peoples of West Africa.
Some writers have also claimed that the Olmec were related to the Mandé peoples of West Africa even though there is absolutely no DNA evidence for this. Such writers have also claimed that Olmec symbols are a script that encodes a Mande language, even though there is no known Mande script until 1949. [7] [8][9] The script claimed to be related to Olmec is actually a set of North African petroglyphs which have not yet even been identified as writing at all, nor definitively connected to any African language let alone to the distant and as yet unknown Olmec language and writing. Mainstream scholars remain unconvinced by these speculations, most regarding them as crackpot. Others are more critical and regard the promotion of such unfounded theories as a form of ethnocentric racism at the expense of indigenous Americans.
By an overwhelming margin the consensus view remains that the Olmec and their achievements are wholly indigenous to the region, founded entirely on a remarkable and ancient agriculture that was indigenous, and that they and neighbouring cultures, with whom they had contact, developed their own characters quite independently of any extra-hemispheric influences.
http://en.wikipedia.org/wiki/Olmec