Navigation Links
Did walking on 2 feet begin with a shuffle?

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
University of Washington

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:
(Date:6/1/2016)... Favorable Government Initiatives Coupled With ... Identification to Boost Global Biometrics System Market Through 2021  ... report, " Global Biometrics Market By Type, By ... 2011 - 2021", the global biometrics market is projected ... of growing security concerns across various end use sectors ...
(Date:5/9/2016)... , UAE, May 9, 2016 ... it comes to expanding freedom for high net worth ... Even in today,s globally connected world, there is still ... system could ever duplicate sealing your deal with a ... second passports by taking advantage of citizenship via investment ...
(Date:4/26/2016)... 2016 Research and Markets has ... Market 2016-2020"  report to their offering.  , ,     ... The analysts forecast the global multimodal biometrics market ... the period 2016-2020.  Multimodal biometrics is ... as the healthcare, BFSI, transportation, automotive, and government ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... , June 27, 2016   Ginkgo Bioworks , ... industrial engineering, was today awarded as one of ... of the world,s most innovative companies. Ginkgo Bioworks ... for the real world in the nutrition, health ... work directly with customers including Fortune 500 companies ...
(Date:6/24/2016)... Epic Sciences unveiled a liquid biopsy ... PARP inhibitors by targeting homologous recombination deficiency (HRD) ... test has already been incorporated into numerous clinical ... Over 230 clinical trials are investigating ... PARP, ATM, ATR, DNA-PK and WEE-1. Drugs targeting ...
(Date:6/24/2016)... , ... June 24, 2016 , ... Researchers at the ... commonly-identified miRNAs in people with peritoneal or pleural mesothelioma. Their findings are the subject ... it now. , Diagnostic biomarkers are signposts in the blood, lung fluid or ...
(Date:6/23/2016)... Wausau, WI (PRWEB) , ... June 23, 2016 ... ... probiotic supplements, is pleased to announce the launch of their brand, UP4™ Probiotics, ... supplements for over 35 years, is proud to add Target to its list ...
Breaking Biology Technology: