Inbreeding research by DNA. A researcher taking a blood sample from a Rhesus Macacque (Macaca mulatta). This animal is one of a group used in virus research. Researchers are trying to produce a group free from the Herpes-B retrovirus, as this seriously affects the results of many of their tests. The problem is caused by inbreeding, so DNA sequences are used to assess the level of inbreeding in the group. Photographed at the University of California at Davis.