For many years, scientists have supported through DNA and behavioral observation that chimpanzees are human’s closest relatives. Also, the advance in technology has enable scientists to find similarities and differences between humans and chimpanzees. DNA has revealed that Homo sapiens and chimpanzees are 98.5 to 99 percent identical. If an individual observes a chimpanzee, he or she will be surprised with the emotional, behavioral, and physical similarities one shares with the chimpanzees. The only differences between the chimpanzees and us would be running on two legs, that alone separates us. The evidence that supports the statement that chimpanzees are Human’s closest living non-human Primate Relatives are DNA and the chimpanzee’s cultural behavior. DNA studies have shown that Homo sapiens and chimpanzees share 99 percent of identical DNA. In the article, “What Makes Us Human?” Katherine S. Pollard focuses on the 1 percent of DNA that makes humans and chimpanzees different. However, the findings revealed a closer relationship between humans and chimpanzees, and explanations of how genes have mutated throughout time. Pollard reports that the human accelerated region 1 (HAR1) “might be part of a gene new to science that is active in the brain” (Pollard, 2009). The human brain is larger, more complex, and organized differently than the chimpanzees’ brain. Pollard, however, suggests that HAR1 might have the explanation to the evolution of the brain because “until human came along, HAR1 evolved extremely slowly” (Pollard, 2009). HAR1 is a gene that is expressed in a set of neurons during the embryo’s development, and it is important because it forms the human’s cerebral cortex.