In 1980, Carter published
Earlier than You Think: A Personal View of Man in America. The book describes Carter's evidence for humans arriving in
North America approximately 100,000 years ago. Much of the information presented had already been published by Carter in the past, but technological advances allowed for a new dating technique called
amino acid dating to be used on ancient human remains.
Amino acid dating was pioneered by Jeffry Bada, who at the time was a geochemist at the
Scripps Institution of Oceanography. The new technique allowed bones to be dated by extracting their protein. Learning of this new means of dating, Carter selected some skulls from the
San Diego Museum of Man to be tested. The skulls were excavated on the California coast by
M.J. Rogers in 1929, and the museum had them dated at 5,000 to 7,000 years old. Bada tested the specimens in 1974, and the dates came back ranging from 20,000 to 70,000 years ago. Carter saw this as definitive proof of the early populating of the Americas. Carter also attacks the mainstream
archaeological establishment throughout the book, claiming that some scholars are closed-minded and too caught up in the generally accepted
archaeological theories to accept his evidence.
Criticism of dating Critics quickly refuted Bada's results. When using amino acid racemization to date bones, one must know the approximate temperature the bones were exposed to while buried. Additionally, the
stratigraphy of the bones suggested dates around 10,000 years ago rather than 70,000. In December 1984, Bada came forward and retracted all the dates of bones gleaned from
amino acid dating. Newer methods of dating, such as
accelerator mass spectrometry gave the same bones dates of less than 10,000 years. ==Hyperdiffusionism==