The human genome consists of three billion base pairs that encode some 100,000 to 300,000 genes. Could we work out all the sequence of this DNA? What use would that information be? The sequence alone would not tell us, today, what the genes were and how they function.
A major goal of biology is to solve the structure-function problem: to be able to predict from the DNA sequence what the structure of a protein might be-and, ultimately, how it might function. The solution to this problem, which may still take several decades, means that we would be able to interpret DNA sequences directly, without further experimentation. Knowing the human sequence by itself doesn't solve this problem, but the information would serve as a massive database for tests of solutions.
A human genome project begins with the construction of a physical map: an ordered collection of 40,000 base pair-long DNA segments ...
