Analysis of CRISPR sequences revealed coevolution of host and viral genomes. Nectar spurs are thought to have played a role in plant-pollinator coevolution. They also have undergone of plant-pathogen coevolution. Factors important for adaption and colonization or possible coevolution are not yet understood. That could be due to host-pathogen coevolution. There is strong evidence for host-parasite coevolution in some groups. Ectoparasites may be collected for studies of coevolution and zoonoses. The results are inapplicable to coevolution of biological species, which does not yield champions. This interaction is known as gene-culture coevolution. These algorithms result in a coevolution scoring matrix. The coevolution of the two mutually imposes selective pressures. The lactose persistence example may be representative of a very general pattern of gene-culture coevolution. There exists evidence of human-canine behavioral coevolution. Metazoans have an amazing ability to increase diversity through coevolution. "Ritual/speech coevolution theory" exemplifies this approach.