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Dear Colleagues - this is to announce that the following new paper on
brains and life history in odontocetes is on-line at http://content.karger.com/ProdukteDB/produkte.asp?Aktion=Ausgabe&ProduktNr=223831&Ausgabe=232071 Lefebvre, L, Marino, L., Sol, D, Lemieux S, Arshad, S. (2006). Large brains and lengthened life history periods in odontocetes. Brain Behavior and Evolution. 268: 218-228. Abstract
Previous work on primates and birds suggests that large brains
require longer periods of juvenile growth, leading to reproductive
constraints due to delayed maturation. We examined the relationship
between brain size and life history periods in cetaceans, a
large-brained mammalian order that has been largely ignored. We looked
at males and females of twenty-five species of odontocetes, using
independent contrasts and multiple regressions to disentangle possible
phylogenetic effects and inter-correlations among life history traits.
We corrected all variables for body size allometry and separated life
span into adult and juvenile periods. For females and both sexes
combined, gestation, time to sexual maturity, time as an adult and life
span were all positively associated with residual brain size in simple
regressions; in multiple regressions maximum life span and time as an
adult were the best predictors of brain size. Males showed few
significant trends. Our results suggest that brain size has co-evolved
with extended life history periods in odontocetes, as it has in
primates and birds, and that a lengthened adult period could have been
an important component of encephalization in cetaceans. For
a reprint please contact me at [EMAIL PROTECTED] Thank
you, Lori
Marino -- Lori Marino, Ph.D. Neuroscience and Behavioral Biology Program 1462 Clifton Road, Suite 304 Emory University Atlanta, GA 30322 Phone: (404) 727-7582 Fax: (404) 727-7471 When one tugs at a single thing in nature, he finds it attached to the rest of the world. - John Muir |
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