Editing Cetacean intelligence (section)

==Brain evolution==
The evolution of encephalization in cetaceans is similar to that in primates.<ref>{{Cite journal |last=Boddy |first=A. M. |date=2012 |title=Comparative analysis of encephalization in mammals reveals relaxed constraints on anthropoid primate and cetacean brain scaling |journal=Journal of Evolutionary Biology |volume=25 |issue=5 |pages=981–994 |doi=10.1111/j.1420-9101.2012.02491.x |pmid=22435703 |doi-access=free}}</ref> Though the general trend in their evolutionary history increased brain mass, body mass, and encephalization quotient, a few lineages actually underwent decephalization, although the selective pressures that caused this are still under debate.<ref name=":0">{{Cite journal |last=Fox |first=Kieran C. R. |date=October 2017 |title=The social and cultural roots of whale and dolphin brains |url=http://eprints.lse.ac.uk/85227/1/Muthukrishna_Understanding%20cumulative.pdf |journal=Nature Ecology & Evolution |volume=1 |issue=11 |pages=1699–1705 |doi=10.1038/s41559-017-0336-y |pmid=29038481 |bibcode=2017NatEE...1.1699F |s2cid=3281492}}</ref> Among cetaceans, Odontoceti tend to have higher encephalization quotients than Mysticeti, which is at least partially due to the fact that Mysticeti have much larger body masses without a compensating increase in brain mass.<ref name=":1">{{Cite journal |last=Montgomery |first=Stephen H. |date=2013 |title=The evolutionary history of cetacean brain and body size |url=http://discovery.ucl.ac.uk/1477166/1/Montgomeryetal_EVOLUTION_AcceptedVersion.pdf |journal=International Journal of Organic Evolution |volume=67 |issue=11 |pages=3339–3353 |doi=10.1111/evo.12197 |pmid=24152011 |doi-access=free |s2cid=24065421}}</ref> As far as which selective pressures drove the encephalization (or decephalization) of cetacean brains, current research espouses a few main theories. The most promising suggests that cetacean brain size and complexity increased to support complex social relations.<ref>{{Cite journal |last=Xu |first=Shixia |date=Fall 2017 |title=Genetic basis of brain size evolution in cetaceans: insights from adaptive evolution of seven primary microcephaly (MCPH) genes |journal=BMC Evolutionary Biology |volume=17 |issue=1 |page=206 |doi=10.1186/s12862-017-1051-7 |pmc=5576371 |pmid=28851290 |doi-access=free |bibcode=2017BMCEE..17..206X }}</ref><ref name=":1" /><ref name=":0" /> It could also have been driven by changes in diet, the emergence of echolocation, or an increase in territorial range.<ref name=":1" /><ref name=":0" />