Dr Patrick Short answers the top genetic questions on quora. Which include:  1) How reliable is the DNA testing offered by sites like Ancestry.com or 23andMe? 2) Does DNA testing for diet and fitness really work? 3) Does 23andMe provide accurate results for people of Indian heritage? 4) How much of the genome does 23andMe sequence? Can their data be used to study disease? 5) How seriously would you take the DNA ancestry and health reports from a place like 23andMe?