I remember growing up hearing this stat given but it always seemed like odd to me.... Now we are finally seeing study's show that is not the case and the number is much much higher.
Sections of human DNA without a clear counterpart in chimp DNA make up approximately 15% to 20% of the genome, Marques-Bonet said. For example, some bits of DNA are present in one species but missing in the other; these are known as "insertions and deletions." In the course of evolution from a common ancestor, some pieces of DNA in one species broke off and reattached elsewhere along the chromosome.So, while earlier studies suggested a 98% to 99% similarity, comparisons that include harder-to-align regions push that difference closer to 5% to 10%, Marques-Bonet said. "And if we account for the regions still too complex to align properly with current technology, the true overall difference is likely to exceed 10%," he said.
Are we close relatives? Yes but there are still significant differences that we haven't even been able to hash out entirely yet.