Um padrão conservado de proporção de cérebros de tubarões a primatas

quarta-feira, junho 30, 2010

A conserved pattern of brain scaling from sharks to primates

Kara E. Yopak a,b,1, Thomas J. Lisney c,d, Richard B. Darlington e, Shaun P. Collin d,f, John C. Montgomery b, and Barbara L. Finlay e

-Author Affiliations

aCenter for Scientific Computation in Imaging, University of California, San Diego, CA 92037;
bLeigh Marine Laboratory, University of Auckland, Leigh 0985, New Zealand;
cDepartment of Animal Ecology, Evolutionary Biology Centre, Uppsala University, 752 36 Uppsala, Sweden;
dSchool of Biomedical Sciences, University of Queensland, St. Lucia, Queensland 4072, Australia;
eDepartment of Psychology, Cornell University, Ithaca, NY 14853; and
fSchool of Animal Biology, University of Western Australia, Crawley, Western Australia 6009, Australia

Edited by Charles F. Stevens, Salk Institute for Biological Studies, La Jolla, CA, and approved June 4, 2010 (received for review February 23, 2010)


Several patterns of brain allometry previously observed in mammals have been found to hold for sharks and related taxa (chondrichthyans) as well. In each clade, the relative size of brain parts, with the notable exception of the olfactory bulbs, is highly predictable from the total brain size. Compared with total brain mass, each part scales with a characteristic slope, which is highest for the telencephalon and cerebellum. In addition, cerebellar foliation reflects both absolute and relative cerebellar size, in a manner analogous to mammalian cortical gyrification. This conserved pattern of brain scaling suggests that the fundamental brain plan that evolved in early vertebrates permits appropriate scaling in response to a range of factors, including phylogeny and ecology, where neural mass may be added and subtracted without compromising basic function.

chondrichthyan    cerebellar foliation   allometry   mammal    neuroevolution


1To whom correspondence should be addressed. E-mail:

Author contributions: K.E.Y., R.B.D., and B.F. designed research; K.E.Y., T.J.L., S.P.C., J.C.M., and B.L.F. performed research; K.E.Y. and T.J.L. collected data on chondrichthyan brain organization; S.P.C. and J.C.M. supervised data collection on chondrichthyan brains; R.B.D. analyzed data; and K.E.Y., T.J.L., R.B.D., and B.L.F. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

This article contains supporting information online at


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