Navigation Links
Did walking on 2 feet begin with a shuffle?
Date:5/29/2008

Somewhere in the murky past, between four and seven million years ago, a hungry common ancestor of todays primates, including humans, did something novel. While temporarily standing on its rear feet to reach a piece of fruit, this protohominid spotted another juicy morsel in a nearby shrub and began shuffling toward it instead of dropping on all fours, crawling to the shrub and standing again.

A number of reasons have been proposed for the development of bipedal behavior, or walking on two feet, and now researchers from the University of Washington and Johns Hopkins University have developed a mathematical model that suggests shuffling emerged as a precursor to walking as a way of saving metabolic energy.

Metabolic energy is produced by what an animal eats, enabling it to move. But it is a limited resource, particularly for young-bearing females which have to take care of and feed their offspring. Finding food is vitally important, and an animal needs to save energy and use it efficiently, said Patricia Kramer, a UW research assistant professor of anthropology and co-author of a recent study.

She believes it was an empty belly, along with a need to conserve energy, that prompted that early ancestor to shuffle.

Hunger. It is always hunger, said Kramer. There is nothing that will get you to do something you dont want to do other than food. Thats why we bribe animals with food to train them.

Because of a huge gap in the fossil record that hides when humans split off from other primates, Kramer and co-author Adam Sylvester, now a postdoctoral fellow at Johns Hopkins University, used the chimpanzee as a way of looking into the past and testing other researchers ideas about the origins of bipedalism.

Chimpanzees are humans closest relatives. They basically walk on all fours, partially resting their weight on the knuckles of their hands.

A chimps body plan is very much like that of a primitive ape, and our last common ancestor probably had a body like that of a chimp. Modern humans are different with long legs and a big head. So chimps are a good place to start, Kramer said.

Using the model they devised, Kramer and Sylvester calculated it would not be metabolically efficient for a chimp to use bipedalism for distances greater than about 50 feet. But it would be efficient and that most shuffling would occur for distances less than 30 feet. In addition, walking on two feet would be used most frequently for distances less than three feet.

These are predictions other people can test. You should rarely, if ever, see a chimp walking upright at longer distances. The flipside of this is if a chimp is going a short distance returning to all fours is not going to happen. You can see this in human babies learning to walk. If they are going between a couch and a coffee table they are up on their feet. But if they are going a longer distance, they go down and crawl, she said.

We think metabolic energy is extremely important and we have only touched the surface of the information we can get with this work. The model allows people to plug in the body characteristics of any primate so a researcher can change the parameters for a specific species.


'/>"/>

Contact: Joel Schwarz
joels@u.washington.edu
206-543-2580
University of Washington
Source:Eurekalert

Related biology news :

1. Walking tall to protect the species
2. War between the sexes begins before twins birth, TAU researchers say
3. iPlant Kickoff Conference at CSHL begins tackling plant biologys grand challenges
4. Clinical trial that may help patients breathe easier begins at Central DuPage Hospital
5. DHS Begins Collecting 10 Fingerprints From International Visitors at New Yorks John F. Kennedy International Airport
6. DHS Begins Collecting 10 Fingerprints From International Visitors at Detroit Metropolitan Wayne County Airport
7. DHS Begins Collecting 10 Fingerprints From International Visitors at Orlando International Airport
8. DHS Begins Collecting 10 Fingerprints From International Visitors at Miami International Airport
9. DHS Begins Collecting 10 Fingerprints From International Visitors at San Francisco International Airport
10. Avian origins: new analysis confirms ancient beginnings
11. DHS Begins Collecting 10 Fingerprints From International Visitors at George Bush Houston Intercontinental Airport
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/13/2016)... CHICAGO , April 13, 2016  IMPOWER physicians ... are setting a new clinical standard in telehealth ... By leveraging the higi platform, IMPOWER patients can ... weight, pulse and body mass index, and, when they ... quick and convenient visit to a local retail location ...
(Date:3/29/2016)... RATON, Florida , March 29, 2016 ... or the "Company") LegacyXChange "LEGX" and SelectaDNA/CSI Protect are ... DNA in ink used in a variety of writing ... theft. Buyers of originally created collectibles from athletes on ... through forensic analysis of the DNA. ...
(Date:3/22/2016)... PROVO and SANDY, ... Screening Ontario (NSO), which operates the highest sample volume ... testing, and Tute Genomics and UNIConnect, leaders in clinical ... today announced the launch of a project to establish ... testing panel. NSO has been contracted ...
Breaking Biology News(10 mins):
(Date:5/3/2016)... , May 3, 2016  Dr. Thomas P. ... in The Woodlands, Texas , now ... percent of treated fat cells in just 25-minutes, leaving ... to 90 percent of Americans report feeling bothered by ... fat reduction procedures are a growing industry. This innovative ...
(Date:5/3/2016)... ... 03, 2016 , ... Nashville Fertility Center has joined a ... reproductive endocrinologists, including Dr. George Hill at Nashville Fertility Center, created ... build families. , Ovation Fertility is a nationwide network of leading fertility centers ...
(Date:5/2/2016)... Willoughby, Ohio (PRWEB) , ... May 02, 2016 ... ... website. Designed with its clients in mind, the fresh look and added functionality ... capabilities. , “Recent years have seen a dynamic shift in agriculture – from ...
(Date:5/2/2016)... PA (PRWEB) , ... May 02, 2016 , ... ... proud to report on the pre-launch success of their revolutionary, veterinarian-designed product for ... cats to stalk, trap, and play with their food the way nature intended. ...
Breaking Biology Technology: