Using a target enrichment approach, Elsa Call, Ph.D., and colleagues used probes (shown as circles) designed to zero in on certain fragments of DNA (spirals). These fragments are associated with specific genes that can be used to determine how closely species are related. This illustration shows three stages (left to right): the probes latching onto the DNA fragments; the fragments after they have been amplified (multiplied) and separated for ease of analysis; and the genes associated with the DNA. (Image courtesy of Elsa Call, Ph.D.)