Scientists at the University of California, Davis, have tested a new method for determining the sex of human remains based on proteins extracted from tooth enamel,media reported. Based on studies of 55 Native American remains from 300 to 2,300 years ago, the technique has proven to be more reliable than DNA-based or bone-based anatomy. Although the study of bone and tooth remains was a key tool for understanding ancient human society, traditional methods of determining the sex of individuals were not always reliable.
The oldest and most widely used methods are based on anatomical differences in male and female bones, but they can only be applied to adults and only to populations that provide large enough samples to produce statistically reliable tables. To make matters worse, these anatomical methods are almost ineffective in dealing with bone fragments.
A more modern approach is to study sex markers through DNA fragments. However, it is well known that even with polymerase chain reaction (PCR) techniques, it is difficult to extract well-preserved, uncontaminated DNA from archaeological sites. Although polymerase chain reactions can be “photocopied” for analysis of tiny DNA samples extracted, dna degradation can also affect its reliability as a gender indicator due to time and environmental influences.
Led by postdoctoral researcher Tammy Buonasera, the team at the University of California, Davis, studied the remains unearthed from two ancestral Oron villages near Suno, California. Scientists extract edited proteins from tooth enamel, rather than studying them through taxonomy or DNA. The team worked in reverse by studying the 20 amino acid sequences that make up the protein to determine the DNA encoding that produces the protein, and then to determine the sex of the tooth-taking person. According to the researchers, the new method is more reliable than anatomy or DNA, which works only in half of the cases studied. In addition, this protein method also applies to the remains of children.