Actually they did not use any one individual's complete DNA, they used a wide variety of DNA strands so it doe not represent a single individual, nor does it represent the Human Race as a whole.

The only way the HGP could have any real solid validity would be if they collected the DNA from all 6.5Billion + human beings and cataloged the entire pool of DNA, some 3 Billion base pairs from some 6.5 Billion individuals. In that way entire "family trees" could be developed. They wil not do this.

Doing this would blow away so many Cultural Myths, so many Racial Myths, so many Ethnic Myths, so many Tribal and National Myths that the whole of Human History as we have recorded it would likely have to be junked as just so much falsehood.

Now, to map the flow of the human population across the geographical terrian over time would be basically impossible as well, as it is now commonly done. The confusion between racial names, geographical names, language names, tribal and national names, and ethnic names would stand out like a swollen sore thumb. We could only begin to map out the current situation, and entirely new names would have to be developed to lable peoples. Without tracking every single individual from that point forward and their offspring the history to be written would be just as basically bogus as what we currently have.

It is possible that several genetic trunks will be seen in the Human Family Tree and several limbs, branches, and such, as well as much higher degree of cross branching than has ever been thought to be the case.

It seems that only a "god" could quickly and throughly track the entire thing.