Research indicates there?s more to genetics then was until recently supposed. We do indeed share much of our genetic makeup with lower species. Also about 45% of our DNA is due to virus DNA from eons of infections, the genetic remnants of which remain and are passed to each generation. Apparently we have evolved a means to suppress the activity of the viral DNA. This suppression activity seems to come from DNA strands that used to be considered ?garbage? DNA, as it did not produce proteins. Now it seems the garbage DNA has a vital role in how and what genes are expressed or suppressed.
This suppression also helps in preventing genetic defects. For instance human males have an X and Y chromosome, whereas the female has 2 X chromosomes. This would be bad for the woman if both X borne genes were expressed, as the woman would produce an excess of hormones as well as other unwanted effects such as large mammary glands, curvaceousness, long silky smooth hair, excessive sex drive, male subservience, velcro lips and exceptional cooking skills. As it happens, one of the X chromosomes is completely suppressed in the normal female. It was also unknown why one identical twin would suffer from a genetic defect, while its sibling would not. Identical twins have identical genes. Again it seems that one twin suppressed the activity of the abnormal gene while the other did not.
A few years ago, the human genome was successfully mapped. This was thought to be all the information we needed to determine which gene produced which protein, and what its effect on the person would be. Now its found we must also map the garbage DNA to find its roll in our lives.
So even if our genetic makeup is similar to a chimp?s, the way it is expressed may be quite different.