Featured Research

from universities, journals, and other organizations

Eye size determined by maximum running speed in mammals

Date:
May 2, 2012
Source:
University of Texas at Austin
Summary:
Maximum running speed is the most important variable influencing mammalian eye size other than body size, according to new research.

Cheetah.
Credit: ian howard / Fotolia

Maximum running speed is the most important variable influencing mammalian eye size other than body size, according to new research from The University of Texas at Austin.

Related Articles


Species with larger eyes usually have higher visual acuity, says Chris Kirk, associate professor in the Department of Anthropology. But what are the ecological factors that cause some mammals to develop larger eyes than others?

"If you can think of mammals that are fast like a cheetah or horse, you can almost guarantee they've got really big eyes," says Kirk. "This gives them better vision to avoid colliding with obstacles in their environment when they're moving very quickly."

Kirk and physical anthropology doctoral student Amber Heard-Booth are the first to apply Leuckart's Law -- a hypothesis that was developed specifically for birds and speed of flight -- to 50 species of mammals. The paper is forthcoming in the journal Anatomical Record. Heard-Booth presented the findings at the 2011 American Association of Physical Anthropology Meeting, where she was awarded the Mildred Trotter Prize for exceptional graduate research in evolutionary morphology.

Previously it was thought that the time of day that an animal is active (nocturnal or diurnal) would be the main factor driving the evolution of mammalian eye size. However, comparative research on the anatomy of the eye has shown that although nocturnal and diurnal species differ in eye shape, they often have similar eye sizes. Although nocturnal species may appear to have bigger eyes because more of the cornea is exposed to let in more light, activity pattern only has a modest effect on eye size.

By comparison, body mass plus maximum running speed together can explain 89 percent of the variation in eye size among mammals.

The researchers controlled for body size and evolutionary relationships, and found that the relationship between eye diameter and maximum running speed is stronger than the relationship between body mass and running speed.

"You start looking at comparative data and one thing that is always going to influence eye size is body size. An elephant is always going to have bigger eyes than a mouse," Kirk says. "Elephants are the biggest animals we measured, but they are not that fast compared to a cheetah or zebra. At the same time, porcupines -- the biggest of the rodents in our sample -- are slow while some smaller rodents are much faster.

"There is going to be the effect of body mass, but when you look at maximum running speed in isolation or when you hold body mass constant, it's still significantly related to eye size," Kirk says. "And when you combine maximum running speed and body mass as your two variables influencing how big an eye is, they can explain almost all of the differences observed between species. This is a highly significant result."


Story Source:

The above story is based on materials provided by University of Texas at Austin. Note: Materials may be edited for content and length.


Journal Reference:

  1. Amber N. Heard-Booth, E. Christopher Kirk. The Influence of Maximum Running Speed on Eye Size: A Test of Leuckart's Law in Mammals. The Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology, 2012; DOI: 10.1002/ar.22480

Cite This Page:

University of Texas at Austin. "Eye size determined by maximum running speed in mammals." ScienceDaily. ScienceDaily, 2 May 2012. <www.sciencedaily.com/releases/2012/05/120502112606.htm>.
University of Texas at Austin. (2012, May 2). Eye size determined by maximum running speed in mammals. ScienceDaily. Retrieved March 30, 2015 from www.sciencedaily.com/releases/2012/05/120502112606.htm
University of Texas at Austin. "Eye size determined by maximum running speed in mammals." ScienceDaily. www.sciencedaily.com/releases/2012/05/120502112606.htm (accessed March 30, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Monday, March 30, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Arthropod Fossil Might Be Relative Of Spiders, Scorpions

New Arthropod Fossil Might Be Relative Of Spiders, Scorpions

Newsy (Mar. 29, 2015) A 508-million-year-old arthropod that swam in the Cambrian seas is thought to share a common ancestor with spiders and scorpions. Video provided by Newsy
Powered by NewsLook.com
Vietnam Rice Boom Piles Pressure on Farmers and the Environment

Vietnam Rice Boom Piles Pressure on Farmers and the Environment

AFP (Mar. 29, 2015) Vietnam&apos;s drive to become the world&apos;s leading rice exporter is pushing farmers in the fertile Mekong Delta to the brink, say experts, with mounting costs to the environment. Duration: 02:35 Video provided by AFP
Powered by NewsLook.com
Raw: Lioness Has Rare Five-Cub Litter

Raw: Lioness Has Rare Five-Cub Litter

AP (Mar. 27, 2015) A lioness in Pakistan has given birth to five cubs, twice the usual size of a litter. Queen gave birth to two other cubs just nine months ago. (March 27) Video provided by AP
Powered by NewsLook.com
Jockey Motion Tracking Reveals Racing Prowess

Jockey Motion Tracking Reveals Racing Prowess

Reuters - Innovations Video Online (Mar. 26, 2015) Using motion tracking technology, researchers from the Royal Veterinary College (RVC) are trying to establish an optimum horse riding style to train junior jockeys, as well as enhance safety, health and well-being of both racehorses and jockeys. Matthew Stock reports. Video provided by Reuters
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