Navigation Links
Biologists Question Animal Brain Size Theory
Date:5/30/2009

Social behavior hypothesis contradicted in research paper

FRIDAY, May 29 (HealthDay News) -- Animals -- carnivores in particular -- that follow a social order do not necessarily develop bigger brains, say two biologists whose findings contradict the so-called Social Brain Hypothesis followed by many evolutionists.

In a report published online May 27 in the Proceedings of the National Academy of Sciences Early Edition, John Finarelli of the University of Michigan and John Flynn of the American Museum of Natural History said their detailed analysis of meat-eating animals -- living and extinct -- shows changes in the size of the animal's brain relative to itself were influenced by more than just sociality within the species.

"This is a sophisticated and powerful analysis that integrates fossils with extant species of carnivores," Flynn, dean of the Richard Gilder Graduate School at the American Museum of Natural History, said in a museum news release. "If you only analyze living forms, you often don't correctly reconstruct the evolutionary transformations. Our research shows another example of this, and indicates that the Social Brain Hypothesis does not hold for all Carnivora."

Past studies have linked sociality, such as the pack structure in wild dogs, to the relative increase in brain size to body size for several classifications of mammals. Finarelli and Flynn said their analysis of brain size to body mass in 289 carnivores -- roughly half of which were fossil species -- showed a story far more complex.

The study found at least six distinct changes in brain sizes for carnivores -- which included bears, dogs, cats and weasels -- and the changes were not universal or uniform. While brain size stayed relatively unchanged in some (for example, most cats), it steadily decreased in the extinct bear-dogs called Amphicyonidae. Meanwhile, for dogs, brain size only recently showed an increase in size despite modern-types of dogs having been around for 10 million years.

The hypothesis further broke down when they looked at relatively large-brained carnivores, such as bears, small cats and weasels. The Social Brain Hypothesis would hold that these animals would have social orders, but in actuality, they don't, the authors said.

More information

The Alzheimer's Association has more about how the brain works.



-- Kevin McKeever



SOURCE: American Museum of Natural History, news release, May 25, 2009


'/>"/>
Copyright©2009 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Where tumor cells boldly go: Weill Cornell cancer biologists shed light on the metastatic niche
2. Cell biologists identify new tumor suppressor for lung cancer
3. Microbiologists receive top Canadian recognition
4. Boston College biologists build a better mouse model for cancer research
5. Biologists Discover How Dengue Virus Matures
6. New From the Heinz Family Philanthropies: 10 New Questions Families Should Ask Before Choosing Long-Term Care
7. Study questions whether Ontarios primary health care reforms serve the sick and poor
8. Rarely Used Closed Doors Slammed Again in U.S. Senate Health Care Reform; Sen. Max Baucus Must Publicly Answer 10 Questions About Mandatory Purchase of Health Insurance
9. Heinz Family Philanthropies (www.heinzfamily.org) Release Questions Families Should Ask About Long-Term Care - 10 Questions to Answer...(www.tenquestionstoanswer.org)
10. Ted Karkus Admits to Financial Relationship With Dr. Richard A. Rosenbloom; Demonstrates Pattern of Improper Influence, Unethical Behavior, Falsification and Distortion; Company Questions What Else Karkus May Be Hiding From Shareholders
11. Sen. Max Baucus: Answer 10 Questions About Mandatory Purchase of Health Insurance Including Why the Public Was Excluded From Todays Committee Meeting
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Biologists Question Animal Brain Size Theory 
(Date:3/29/2017)... ... March 29, 2017 , ... AngioGenesis Labs sold 300 bottles ... AngioGenesis Labs, makers of HeartBoost, BrainBest and BeautyBest, achieved these results while doing ... an over the counter heart healthy drink, can reduce Arterial Plaque, Lower Blood ...
(Date:3/29/2017)... ... March 29, 2017 , ... ... growing as it continues developing an ANSI-approved, consensus-based American National Standard for ... plans to publish the first ANSI-approved GMP standard for dietary supplements this ...
(Date:3/29/2017)... ... March 29, 2017 , ... HealthCareMandA.com will host an ... 20, 2017, at 1:00 PM ET. A recording of the webinar will also be ... Series. , Home health and hospice companies are still popular targets for healthcare investors. ...
(Date:3/29/2017)... (PRWEB) , ... March 29, 2017 , ... ... of Gastrointestinal Oncology™ (SOGO™), a specialized continuing medical education conference for clinicians who ... at Intercontinental Time Square, New York. , The program will be led ...
(Date:3/28/2017)... , ... March 28, 2017 , ... Tuesday, March 28, ... American public to take the Diabetes Risk Test to find out if they are ... Angeles World Airports will light up the evening sky by programming the LAX pylons ...
Breaking Medicine News(10 mins):
(Date:3/29/2017)... SAN DIEGO , March 29, 2017 /PRNewswire/ ... company focused on transforming spine surgery with minimally ... Drug Administration (FDA) 510(k) clearance of the CoRoent® ... at multiple contiguous levels in the cervical spine. ... cervical cage to be used at up to ...
(Date:3/29/2017)... , March 29, 2017 NetworkNewsWire ... ... the public safety in regulating marijuana, but economic arguments also ... creation, and reduced law enforcement costs. However, to legalize and ... provided by SinglePoint, Inc. (OTC: SING) ( SING Profile ), ...
(Date:3/29/2017)... /PRNewswire/ - Medicure Inc. ("Medicure") (TSXV:MPH, OTC:MCUJF), a specialty ... year ended December 31, 2016 after market close ... being released later than the previous fiscal year,s ... operations and balances of Apicore from the acquisition ... filing date meets TSX Venture Exchange listed company ...
Breaking Medicine Technology: