text: FISH can be used to study the evolution of chromosomes. Species that are related have similar chromosomes. This homology can be detected by gene or genome sequencing but also by FISH. For instance, human and chimpanzee chromosomes are very similar and FISH can demonstrate that two chimpanzee chromosomes fused to result in one human chromosome. Similarly, species that are more distantly related, have similar chromosomes but with increasing distance chromosomes tend to break and fuse and thus result in mosaic chromosomes. This can be impressively demonstrated by FISH (see figure).