About Careers Internship MedBlogs Contact us
Medindia LOGIN REGISTER
Advertisement

Brain Size Relative to Body Size 'Cannot Clearly Predict Animal's Intelligence': Analysis

by Rukmani Krishna on October 20, 2012 at 11:36 PM
Font : A-A+

 Brain Size Relative to Body Size 'Cannot Clearly Predict Animal's Intelligence': Analysis

The most common measure of intelligence in animals, brain size relative to body size, may not be as dependent on evolutionary selection on the brain as previously thought, concludes a new analysis by scientists.

Brain size relative to body size has been used by generations of scientists to predict an animal's intelligence. For example, although the human brain is not the largest in the animal kingdom in terms of volume or mass, it is exceptionally large considering our moderate body mass.

Advertisement

Now, a study by a team of scientists at UCL, the University of Konstanz, and the Max Planck Institute of Ornithology has found that the relationship between the two traits is driven by different evolutionary mechanisms in different animals.

Crucially, researchers have found that the most significant factor in determining relative brain size is often evolutionary pressure on body size, and not brain size.
Advertisement

For example, the evolutionary history of bats reveals they decreased body size much faster than brain size, leading to an increase in relative brain size. As a result, small bats were able to evolve improved flying manoeuvrability while maintaining the brainpower to handle foraging in cluttered environments.

This shows that relative brain size cannot be used unequivocally as evidence of selection for intelligence.

"When using brain size relative to body size as a measure of intelligence, the assumption has always been that this measure is primarily driven by changes in brain size. It now appears that the relationship between changes in brain and body size in animals is more complex than has long been assumed," said Dr Jeroen Smaers (UCL Anthropology and UCL Genetics, Evolution and Environment), lead author of the study.

"Changes in body size often occur independently of changes in brain size and vice versa. Moreover, the nature of these independent changes in brain and body size, are different in different groups of animals," Dr Smaers added.

Researchers at UCL gathered data on brain and body mass for hundreds of modern and extinct bats, carnivorans, and primates. They then charted brain and body size evolution over time for each species. Across millions of years, most animals increased body size faster than brain size, with the exception of bats.

In primate lineages decreases in brain size marginally outpaced those in body size. Carnivoran evolution has taken yet a different course, with changes generally more strongly associated with body size rather than selection on brain size and cognition.

Given such differences, the authors believe that the predominant interpretation of relative brain size as the consequence of selection on intelligence inherently masks the often more significant influence of selection on body size.

The study is published today in the Proceedings of the National Academy of Sciences.

Source: ANI
Advertisement

Advertisement
News A-Z
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
What's New on Medindia
Top 10 Vitamin B12 Foods for Vegetarians - Slideshow
Targeted Screening Program Beneficial for Prostate Cancer Screening
Are Menopause Symptoms Troubling You?: Try these Options
View all
Recommended Reading
News Archive
Date
Category
Advertisement
News Category

Medindia Newsletters Subscribe to our Free Newsletters!
Terms & Conditions and Privacy Policy.

More News on:
Parkinsons Disease Parkinsons Disease Surgical Treatment BMI Brain Brain Facts Ataxia Healthy Living Language Areas in The Brain Ways to Improve your Intelligence Quotient (IQ) 

Most Popular on Medindia

Find a Hospital Calculate Ideal Weight for Infants Iron Intake Calculator Blood - Sugar Chart Blood Pressure Calculator Turmeric Powder - Health Benefits, Uses & Side Effects Nutam (400mg) (Piracetam) Daily Calorie Requirements Noscaphene (Noscapine) Post-Nasal Drip

Disclaimer - All information and content on this site are for information and educational purposes only. The information should not be used for either diagnosis or treatment or both for any health related problem or disease. Always seek the advice of a qualified physician for medical diagnosis and treatment. Full Disclaimer

© All Rights Reserved 1997 - 2022

This site uses cookies to deliver our services. By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Use