The International HapMap Project is analyzing DNA from populations with African, Asian, and European ancestry. The decision to study these populations is based on knowledge of the history of the human population. All the common haplotypes in human chromosomes occur within these populations, though they may be more common in one than another.
A haplotype is a set of single nucleotide polymorphisms (SNPs). The International HapMap project is working to identify the majority of the over 10 million SNPs that frequently occur in the human genome.
So far, a total of 270 people have provided DNA samples to the HapMap project. 90 of these are from Nigeria, 45 from Japan, 45 from China, and 90 from US residents with European ancestry. Several additional population are being considered for future studies.