Featured Research

from universities, journals, and other organizations

Big-brained Animals Evolve Faster

Date:
August 15, 2008
Source:
University of Chicago Press Journals
Summary:
Ecologists and evolutionary biologists analyzed body size measures of 7,209 species of birds and found that avian families that have experienced the greatest diversification in body size tend to be those with brains larger than expected for their body size.

Parrots have a big brain and are also one of the most evolutionarily diversified bird clades.
Credit: Daniel Sol

Ever since Darwin, evolutionary biologists have wondered why some lineages have diversified more than others. A classical explanation is that a higher rate of diversification reflects increased ecological opportunities that led to a rapid adaptive radiation of a clade.

Related Articles


A textbook example is Darwin finches from Galapagos, whose ancestor colonized a competitors-free archipelago and rapidly radiated in 13 species, each one adapted to use the food resources in a different way. This and other examples have led some to think that the progenitors of the major evolutionary radiations are those that happened to be in the right place and at the right time to take advantage of ecological opportunities.

However, is it possible that biological diversification not only depends on the properties of the environment an ancestral species finds itself in, but also on the features of the species itself? Now a study supports this possibility, suggesting that possessing a large brain might have facilitated the evolutionary diversification of some avian lineages.

Over 20 years ago, Jeff Wyles, Allan Wilson, and Joseph Kunkel proposed that big brains might favor adaptive evolutionary diversification in animals by facilitating the behavioral changes needed to use new resources or environments, a theory known as the behavioral drive hypothesis. When these authors formulated their hypothesis, evidence that the size of the brain limits the cognitive capacity of animals were scanty.

Since then, however, a substantial body of evidence has confirmed that animals with larger brains, relative to their body size, have more developed skills for changing their behavior through learning and innovation, facilitating the invasion of novel environments and the use of novel resources. Despite the progress, the role of the brain in the adaptive diversification of animals has remained controversial, mostly due to the difficulties to demonstrate that big-brained animals evolve faster.

Now, ecologist Daniel Sol of CREAF-Autonomous University of Barcelona and evolutionary biologist Trevor Price of the University of Chicago, provide evidence for such a role in birds in an article in The American Naturalist. Analyzing body size measures of 7,209 species (representing 75% of all avian species), they found that avian families that have experienced the greatest diversification in body size tend to be those with brains larger than expected for their body size.

These include the Picidae (woodpeckers), Bucerotidae (hornbills), Psittacidae (parrots), Strigidae (owls), Menuridae (lyrebirds) and Corvidae (crows). Brain size can promote morphological diversification because it facilitates range expansions and speciation, yet the analyses indicate that the brain-diversification association is statistically independent of geographic range and species richness.

"The most likely alternative," Daniel Sol states, "is that big brains enhance the rate of evolutionary diversification by facilitating changes in behavior, which would place new selection pressures on populations and favor adaptive divergence." Thus, in species with high cognitive styles, behavior might be, along with environmental factors, a major driving force for evolution.


Story Source:

The above story is based on materials provided by University of Chicago Press Journals. Note: Materials may be edited for content and length.


Journal Reference:

  1. Sol et al. Brain Size and the Diversification of Body Size in Birds.. The American Naturalist, 2008; 172 (2): 170 DOI: 10.1086/589461

Cite This Page:

University of Chicago Press Journals. "Big-brained Animals Evolve Faster." ScienceDaily. ScienceDaily, 15 August 2008. <www.sciencedaily.com/releases/2008/08/080814210006.htm>.
University of Chicago Press Journals. (2008, August 15). Big-brained Animals Evolve Faster. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2008/08/080814210006.htm
University of Chicago Press Journals. "Big-brained Animals Evolve Faster." ScienceDaily. www.sciencedaily.com/releases/2008/08/080814210006.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins