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 , ... ... payment industry today announced its strategic partnership with Connance, a healthcare industry ... The two companies’ proven, proprietary technology combine to provide health systems, hospitals ...
(Date:6/26/2016)... ... 2016 , ... Pixel Film Studios Released ProSlice Levels, a Media Slicing Effect ... videos a whole new perspective by using the title layers in ProSlice Levels ... , ProSlice Levels contains over 30 Different presets to choose from. FCPX ...
(Date:6/25/2016)... (PRWEB) , ... June 25, 2016 , ... Austin residents ... the American College of Mohs Surgery and to Dr. Russell Peckham for medical and ... highly effective treatment for skin cancer. The selective fellowship in Mohs Micrographic Surgery completed ...
(Date:6/25/2016)... ... June 25, 2016 , ... Dr. ... from injury. Recently, he has implemented orthobiologic procedures as a method for treating ... one of the first doctors to perform the treatment. Orthobiologics are substances that ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... June 19, ... the dangers associated with chronic pain and the benefits of holistic treatments, Serenity ... who are suffering with Sickle Cell Disease. , Sickle Cell Disease (SCD) is a ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... Mass. , June 24, 2016   Pulmatrix, ... pharmaceutical company developing innovative inhaled drugs, announced today that ... Russell Investments reconstituted its comprehensive set of ... "This is an important milestone for Pulmatrix," ... will increase shareholder awareness of our progress in developing ...
(Date:6/24/2016)... , June 24, 2016  Arkis BioSciences, a ... invasive and more durable cerebrospinal fluid treatments, today ... The Series-A funding is led by Innova Memphis, ... and other private investors.  Arkis, new financing will ... and the market release of its in-licensed Endexo® ...
(Date:6/23/2016)... , June 23, 2016 Research and ... Global Market - Forecast to 2022" report to their ... treatment method for the patients with kidney failure, it replaces ... fluid from the patient,s blood and thus the treatment helps ... and chloride in balance. Increasing number of ...
Breaking Medicine Technology: