Navigation Links
Dogs chase efficiently, but cats skulk counterintuitively
Date:12/3/2008

DURHAM, N.C. -- A Duke University study suggests that evolution can behave as differently as dogs and cats. While the dogs depend on an energy-efficient style of four-footed running over long distances to catch their prey, cats seem to have evolved a profoundly inefficient gait, tailor-made to creep up on a mouse or bird in slow motion.

"It is usually assumed that efficiency is what matters in evolution," said Daniel Schmitt, a Duke associate professor of evolutionary anthropology. "We've found that's too simple a way of looking at evolution, because there are some animals that need to operate at high energy cost and low efficiency."

Namely cats.

In a report published online Nov. 26 in the research journal Public Library of Science (PLoS), Schmitt and two former Duke co-researchers followed up on a scientific hunch by measuring and videotaping how six housecats moved along a 6 yard-long runway in pursuit of food treats or feline toys.

Long-distance chase predators like dogs can reduce their muscular work needed to move forward by as much as 70 percent by allowing their body to rise and fall and exchanging potential and kinetic energy with each step. In contrast, the maximum for cats is about 37 percent and much lower than that in a stalking posture, the report found.

"An important implication of these results is the possibility of a tradeoff between stealthy walking and economy of locomotion," the three researchers wrote in PLoS. "These data show a previously unrecognized mechanical relationship in which crouched postures are associated with changes in footfall pattern, which are in turn related to reduced mechanical energy recovery."

In other words, they found that when cats slink close to the ground they walk in a way that "the movements of their front and back ends cancel each other out," Schmitt said. While that's not good for energy efficiency "the total movement of their bodies is going to be even and they'll be flowing along," he added

"If they're creeping, they're going to put this foot down, and then that foot down and then that one in an even fashion. We think it has to do with stability and caution, Schmitt said."

Walking humans recover as much energy as dogs, said Schmitt, who studies gaits of various mammals. "Our centers of mass rise and fall when we walk. And when we do that, humans and other animals exchange potential and kinetic energy. It's an evolutionary miracle in my view.

"But cats need to creep up on their prey. Most scientists think that energetic efficiency is the currency of natural selection. Here we've shown that some animals make compromises when they have to choose between competing demands."


'/>"/>

Contact: Monte Basgall
monte.basgall@duke.edu
919-681-8057
Duke University
Source:Eurekalert

Related biology news :

1. U.S. Army and Navy Purchase Over 10,000 New Beretta M9 Pistols
2. U.S. Army and Navy Purchase Over 10,000 New Beretta M9 Pistols
3. McPherson County Kansas to Purchase Stingers
4. Fox Chase researchers discover a method for clamping down on a cancer-promoting enzyme
5. Canyon County Idaho Sheriffs Office to Purchase Stinger S-200s
6. bioMETRX, Inc. Completes Sequiam Asset Purchase
7. 1-hit event provides new opportunity for colon cancer prevention, say Fox Chase researchers
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/29/2016)... BOCA RATON, Florida , March 29, 2016 /PRNewswire/ ... ("LegacyXChange" or the "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect ... Synthetic DNA in ink used in a variety of ... preventing theft. Buyers of originally created collectibles from athletes ... authenticity through forensic analysis of the DNA. ...
(Date:3/18/2016)... --> --> Competitive Landscape Analysis ... Physical infrastructure and Perimeter Surveillance & Detection Systems ... and the continuing migration crisis in the Middle ... led visiongain to publish this unique report, which is crucial ... & security companies in the border security market and the ...
(Date:3/14/2016)... March 14, 2016 http://www.apimages.com ... --> - Renvoi : image disponible via ... --> --> DERMALOG, le ... de nouveaux lecteurs d,empreintes digitales pour l,enregistrement des ... sera utilisé pour produire des cartes d,identité aux ...
Breaking Biology News(10 mins):
(Date:5/3/2016)... 2016 The report "Biochips ... Gene Expression) Lab-on-a-chip (IVD & POC, Proteomics), ... Centers), Fabrication Technology (Microarrays, Microfluidics) - Forecast ... is expected to reach USD 17.75 Billion ... 2015, growing at a CAGR of 18.4% ...
(Date:5/3/2016)... ... May 03, 2016 , ... In a list published by the Boston ... 76 fastest-growing private companies; a small percentage of the state's 615,000+ small businesses. The ... percent change in revenue from 2012 to 2015. , As this award ...
(Date:5/3/2016)... CO (PRWEB) , ... May 03, 2016 , ... ... , announced the addition of Dr. Nancy Gillett to its Board of Directors. ... position, she served as Corporate Executive Vice President and Chief Scientific Officer. A ...
(Date:5/3/2016)... ... May 03, 2016 , ... Wearable Tech + Digital ... will take place on June 7-8, 2016, at the New York Academy of Sciences.  ... technology -- including AR/VR, machine learning, apps, robotics and AI -- throughout a major ...
Breaking Biology Technology: