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.
Aeron Haworth | alfa
Cancer diagnosis: no more needles?
25.05.2018 | Christian-Albrechts-Universität zu Kiel
Less is more? Gene switch for healthy aging found
25.05.2018 | Leibniz-Institut für Alternsforschung - Fritz-Lipmann-Institut e.V. (FLI)
The more electronics steer, accelerate and brake cars, the more important it is to protect them against cyber-attacks. That is why 15 partners from industry and academia will work together over the next three years on new approaches to IT security in self-driving cars. The joint project goes by the name Security For Connected, Autonomous Cars (SecForCARs) and has funding of €7.2 million from the German Federal Ministry of Education and Research. Infineon is leading the project.
Vehicles already offer diverse communication interfaces and more and more automated functions, such as distance and lane-keeping assist systems. At the same...
A research team led by physicists at the Technical University of Munich (TUM) has developed molecular nanoswitches that can be toggled between two structurally different states using an applied voltage. They can serve as the basis for a pioneering class of devices that could replace silicon-based components with organic molecules.
The development of new electronic technologies drives the incessant reduction of functional component sizes. In the context of an international collaborative...
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
25.05.2018 | Event News
02.05.2018 | Event News
13.04.2018 | Event News
25.05.2018 | Event News
25.05.2018 | Machine Engineering
25.05.2018 | Life Sciences