By Richard Wheeler (Zephyris) 2007. Image of E...

Image via Wikipedia

I am often asked the question “How can my DNA identify me as a unique individual when all humans have 99.9% the same DNA? This is a great question. We have some 3 billion plus DNA letters in our genes. So a 1/10 of 1% difference represents still about 3 million differences. These differences account for how we look and who we are. Forensics cannot economically read all 3 billion codes from every sample yet. Instead, it knows areas where differences are located and samples only these areas. The Access Excellence Resource Center has an interesting article on this titled “Use of DNA in Identification”. So we are mostly the same as each other but our differences are in the tiny details.