Featured Research

from universities, journals, and other organizations

Infant Carrying Ruled Out As Reason Why Early Humans Walked Upright, According To New Research

Date:
April 23, 2008
Source:
University of Manchester
Summary:
Scientists investigating the reasons why early humans -- the so-called hominins -- began walking upright say it's unlikely that the need to carry children was a factor, as has previously been suggested.

A volunteer carrying baby mannequin on the hip has her energy consumption measured.
Credit: Image courtesy of University of Manchester

Scientists investigating the reasons why early humans -- the so-called hominins -- began walking upright say it's unlikely that the need to carry children was a factor, as has previously been suggested.

Carrying babies that could no longer use their feet to cling to their parents in the way that young apes can has long been thought to be at least one explanation as to why humans became bipedal.

But University of Manchester researchers investigating the energy involved in carrying a child say the physical expense to the mother does not support the idea that walking upright was an evolutionary response to child transportation.

"Walking upright is one of the major characteristics that separates humans from their primate relatives," said Dr Jo Watson, who carried out the research in the University's Faculty of Life Sciences.

"Scientists have long hypothesised as to the reasons why hominins became bipedal in a relatively short space of time but the truth is we still don't know for sure.

"One of the more popular explanations is that walking upright freed our forelimbs allowing us to carry objects, including children; apes have no need to carry their young as they are able to grip using both hands and feet.

"Our study focused on the amount of energy required to carry 10kg loads, including a mannequin child. Importantly, the distribution of the weight varied in each instance."

The team monitored the oxygen consumption of seven women, all healthy individuals under the age of 30, carrying either a symmetric load, in the form of a weighted vest or a 5kg dumbell in each hand, or an asymmetric load, which was a single 10kg weight carried in one hand or a mannequin infant on one hip.

"Carrying an awkward asymmetric load, such as the infant on one side of the body, is the most energetically expensive way of transporting the weight," said Dr Watson, whose research is published in the Journal of Human Evolution.

"Unless infant carrying resulted in significant benefits elsewhere, the high cost of carrying an asymmetrical weight suggests that infant carrying was unlikely to have been the evolutionary driving force behind bipedalism."

The study, carried out with colleagues at the Universities of Sheffield and Salford and funded by the Natural Environment Research Council (NERC), is part of a larger project, run by Dr Bill Sellers at The University of Manchester, which uses computer simulations to understand evolutionary processes, particularly the way in which we and other animals move.

Future plans are to extend this work to assess the energy cost of carrying in great apes. Computer models of early hominins carrying loads will also be built to try and evaluate whether their body shape and posture -- long arms and short legs -- would have made them noticeably better or worse at carrying than present-day humans. The research team hopes this will help build up a picture of how humans evolved to walk on two legs.


Story Source:

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


Cite This Page:

University of Manchester. "Infant Carrying Ruled Out As Reason Why Early Humans Walked Upright, According To New Research." ScienceDaily. ScienceDaily, 23 April 2008. <www.sciencedaily.com/releases/2008/04/080423093254.htm>.
University of Manchester. (2008, April 23). Infant Carrying Ruled Out As Reason Why Early Humans Walked Upright, According To New Research. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2008/04/080423093254.htm
University of Manchester. "Infant Carrying Ruled Out As Reason Why Early Humans Walked Upright, According To New Research." ScienceDaily. www.sciencedaily.com/releases/2008/04/080423093254.htm (accessed August 20, 2014).

Share This




More Fossils & Ruins News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Newsy (Aug. 15, 2014) A mother and son in Alaska uncovered woolly mammoth tusks in the same river more than two decades apart. Video provided by Newsy
Powered by NewsLook.com
Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Newsy (Aug. 14, 2014) Newly found fossils reveal a previously unknown species of flying reptile with a really weird head, which some say looks like a butterfly. Video provided by Newsy
Powered by NewsLook.com
Clearing WWII's Explosive Legacy in the Pacific

Clearing WWII's Explosive Legacy in the Pacific

AFP (Aug. 11, 2014) The hulks of tanks can still be found rusting in the jungles of Palau, but the fierce fighting that scarred the Pacific island nation in WWII has left a more dangerous legacy - unexploded bombs that pose a constant risk to locals. Duration: 00:47 Video provided by AFP
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:
from the past week

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