Scientists say that humans and chimps have 96-98% similar DNA. While that sounds like we are closely related, let’s first put it into perspective. The 2-4% gap equals to 35 million differences. In addition, humans have 40-45 million base pairs that chimps don’t have, and chimps have 45 million base pairs that humans don’t have. It should be noted that many of the similarities are in the proteins. If one protein codes for a certain function or characteristic, then we can conclude that the same protein can be used for a trait in other life forms. The differences that we see may be the result of DNA coding. Just like the illustration used about the painter, we can expect that many forms of life have similarities in the coding proteins, especially if those proteins are important in the structure of life. Here are some similarities: Humans and chickens have 60% similarities, and humans and rats have 88% similarities. Watermelons, jellyfish, and clouds are made up of 98% water, so by that reasoning, would they all be the same thing? No, of course not.
This is an often asked question and can be better explained by a Ph.D. in microbiology. Please see the following link: http://www.answersingenesis.org/articles/aid/v4/n1/are-humans-chimps-related