Navigation Links
Walking tall to protect the species
Date:12/12/2007

The transition from apes to humans may have been partially triggered by the need to stand on two legs, in order to safely carry heavier babies. This theory1 of species evolution presented by Lia Amaral from the University of So Paulo in Brazil has just been published online in Springers journal, Naturwissenschaften.

For safety, all nonhuman primates carry their young clinging to their fur from birth, and species survival depends on it. The carrying pattern changes as the infant grows. Newborns are carried clinging to their mothers stomach, often with additional support. Months later, infants are carried over the adult body usually on the mothers back, and this carrying pattern lasts for years in apes. However, this necessity to carry infants safely imposes limits on the weight of the infants.

Through a detailed mechanical analysis of how different types of apes - gibbons, orangutans and gorillas - carry their young, looking at the properties of ape hair, infant grip, adult hair density and carrying position, Amaral demonstrates a relationship between infant weight, hair friction and body angle which ensures ape infants are carried safely.

Amaral also shows how the usual pattern of primate carrying of heavy infants is incompatible with bipedalism. African apes have to persist with knuckle-walking on all fours, or quadruped position, in order to stop their young from slipping off their backs.

The author goes on to suggest that the fall in body hair in primates could have brought on bipedality as a necessary consequence, through the strong selective pressure of safe infant carrying, as infants were no longer able to cling to their mothers body hairs. In the authors opinion, safe carrying of heavy infants justified the emergence of the biped form of movement. Although an adult gorilla is much heavier than an adult human, its offspring is only half the weight of a human baby.

Amaral concludes that this evolution to bipedality has important consequences for the female of the species. Indeed, it frees the arms and hands of males and juveniles, but females have their arms and hands occupied with their young. This restriction of movement placed limits on food gathering for biped females carrying their infants, and may have been at the origin of group cooperation.


'/>"/>

Contact: Joan Robinson
joan.robinson@springer.com
49-622-148-78130
Springer
Source:Eurekalert

Related biology news :

1. Rain forest protection works in Peru
2. Same gene protects from 1 disease, opens door to another
3. Conservation International and Toyota partner to protect Philippines rain forests
4. Fungus genome yielding answers to protect grains, people and animals
5. Genes that both extend life and protect against cancer identified
6. Intravenous gene therapy protects normal tissue of mice during whole-body radiation
7. Rosemary chicken protects your brain from free radicals
8. Genes identified to protect brassicas from damaging disease
9. Antioxidants could provide all-purpose radiation protection
10. Secure Services Corp. Achieves Milestone in United States Identity Protection with the Launch of the SSC SHAPE Card Management Solution
11. Omega-3 fatty acids protect against Parkinsons, study says
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/25/2016)... Unisys Corporation (NYSE: UIS ) today announced the implementation ... New York City , to help U.S. ... the United States using passports that are ... of the system at Dulles last year. The system will ... 2016. --> pilot testing of the system at ...
(Date:1/21/2016)... January 21, 2016 ... new market research report "Emotion Detection and Recognition Market by ... Tools (Facial Expression, Voice Recognition and Others), Services, ... forecast to 2020", published by MarketsandMarkets, the global ... reach USD 22.65 Billion by 2020, at a ...
(Date:1/18/2016)... Jan. 18, 2016  Extenua Inc., a pioneering ... the use and access of ubiquitous on-premise and ... with American Cyber.  ... leading transformational C4ISR and Cyber initiatives in support ... latest proven technology solutions," said Steve Visconti ...
Breaking Biology News(10 mins):
(Date:2/9/2016)... (PRWEB) , ... February 09, 2016 , ... The ... the organization’s history, it is offering its 2016 AAT Member Certification Qualification Course for ... The curriculum for the webinar, which will include a detailed review of hardware, software, ...
(Date:2/9/2016)... , ... February 09, 2016 , ... ... Vice President for Public Policy for the National Organization for Rare Disorders (NORD). ... groups to ensure their voices are heard throughout the drug regulatory review process. ...
(Date:2/9/2016)... YORK , Feb. 9, 2016 This ... analyzes the current and future prospects of the market ... this report include companies engaged in the manufacture of ... an executive summary with a market snapshot providing the ... scope of this report. This section also provides the ...
(Date:2/9/2016)... -- Three-Year Initiative Supports Next Generation of Medical ... Life-Changing Camp Experiences ... the lives of children born with rare diseases, as well as ... is announcing a new initiative designed to positively affect the lives ... of rare disease care. --> To mark the company,s ...
Breaking Biology Technology: