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:6/27/2016)... ... June 27, 2016 , ... TopConsumerReviews.com recently awarded their highest ... . , Millions of individuals in the United States and Canada wear eyeglasses. Once ... to both correct vision and make a fashion statement. Even celebrities use glasses as ...
(Date:6/26/2016)... ... June 26, 2016 , ... PawPaws brand pet supplements ... was developed to enhance the health of felines. The formula is all-natural and is ... herbs in the PawPaws Cat Kidney Support Supplement Soft Chews are Astragalus ...
(Date:6/25/2016)... ... ... Austin residents seeking Mohs surgery services, can now turn to Dr. Jessica Scruggs ... for medical and surgical dermatology. , Dr. Dorsey brings specialization to include Mohs surgery, ... Micrographic Surgery completed by Dr. Dorsey was under the direction of Glenn Goldstein, MD, ...
(Date:6/25/2016)... ... ... As a lifelong Southern Californian, Dr. Omkar Marathe earned his Bachelors in ... School of Medicine at UCLA. He trained in Internal Medicine at Scripps Green Hospital ... at the UCLA-Olive View-Cedars Sinai program where he had the opportunity to train in ...
(Date:6/24/2016)... Angeles, CA (PRWEB) , ... June 24, 2016 , ... ... surgery procedures that most people are unfamiliar with. The article goes on to state ... procedures, but also many of these less common operations such as calf and cheek ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... , June 23, 2016 ... Oticon , industry leaders in advanced ... launch of Oticon Opn ™, the world,s first ... of possibilities for IoT devices.      (Photo: ... Oticon introduces a number of ,world firsts,: ...
(Date:6/23/2016)... -- Research and Markets has announced the ... (United States, China, Japan, Brazil, United Kingdom, Germany, France, ... Surgical Procedure Volumes: ... provides surgical procedure volume data in a geographic context. ... analysis of growth drivers and inhibitors, including world population ...
(Date:6/23/2016)... -- The National Pharmaceutical Council (NPC) today announced that ... organization as its newest member.  ... and chief scientific officer, Mallinckrodt Pharmaceuticals, will serve ... of Directors. ... in support of our efforts to conduct research ...
Breaking Medicine Technology: