Navigation Links
Anthropologist finds explanation for hominin brain evolution in famous fossil
Date:5/7/2012

TALLAHASSEE, Fla. -- One of the world's most important fossils has a story to tell about the brain evolution of modern humans and their ancestors, according to Florida State University evolutionary anthropologist Dean Falk.

The Taung fossil the first australopithecine ever discovered has two significant features that were analyzed by Falk and a group of anthropological researchers. Their findings, which suggest brain evolution was a result of a complex set of interrelated dynamics in childbirth among new bipeds, were published May 7 in the prestigious Proceedings of the National Academy of Sciences.

"These findings are significant because they provide a highly plausible explanation as to why the hominin brain might grow larger and more complex," Falk said.

The first feature is a "persistent metopic suture," or unfused seam, in the frontal bone, which allows a baby's skull to be pliable during childbirth as it squeezes through the birth canal. In great apes gorillas, orangutans and chimpanzees the metopic suture closes shortly after birth. In humans, it does not fuse until around 2 years of age to accommodate rapid brain growth.

The second feature is the fossil's endocast, or imprint of the outside surface of the brain transferred to the inside of the skull. The endocast allows researchers to examine the brain's form and structure.

After examining the Taung fossil, as well as huge numbers of skulls belonging to apes and humans, as well as corresponding 3-D CT (three-dimensional computed tomographic) scans, and taking into account the fossil record for the past 3 million years, Falk and her colleagues noted three important findings: The persistent metopic suture is an adaptation for giving birth to babies with larger brains; is related to the shift to a rapidly growing brain after birth; and may be related to expansion in the frontal lobes.

"The persistent metopic suture, an advanced trait, probably occurred in conjunction with refining the ability to walk on two legs," Falk said. "The ability to walk upright caused an obstretric dilemma. Childbirth became more difficult because the shape of the birth canal became constricted while the size of the brain increased. The persistent metopic suture contributes to an evolutionary solution to this dilemma."

The later fusion of the metopic suture is most likely an adaptation of hominins who walked upright to be able to more easily give birth to babies with relatively large brains. The unfused seam is also related to the shift to rapidly growing brains after birth, an advanced human-like feature as compared to apes.

"The later fusion was also associated with evolutionary expansion of the frontal lobes, which is evident from the endocasts of australopithecines such as Taung," Falk said.

The Taung fossil, which is estimated to be around 2 million years old, was discovered in 1924 in Taung, South Africa. It became the "type specimen," or main model, of the genus Australopithecus africanus when it was announced in 1925.

An australopithecine is any species of the extinct genera Australopithecus or Paranthropus that lived in Africa, walked on two legs and had relatively small brains.


'/>"/>
Contact: Dean Falk
dfalk@fsu.edu
505-954-7249
Florida State University
Source:Eurekalert

Related biology news :

1. Anthropologist discovers new fossil primate species in West Texas
2. Missouri elk are being reintroduced in the wrong part of the state, MU anthropologist says
3. Recently analyzed fossil was not human ancestor as claimed, anthropologists say
4. Hobbit fossils represent a new species, concludes University of Minnesota anthropologist
5. Texas A&M anthropologist discovers long-lost primate in Indonesia
6. LSU research finds orangutans host ancient jumping genes
7. Syracuse University study finds autumn advantage for invasive plants in eastern United States
8. Pacific islands may become refuge for corals in a warming climate, study finds
9. New study finds a protein combination is best to consume post-workout for building muscle
10. Study finds Western diet detrimental to fetal hippocampal tissue transplants
11. Study finds soda consumption increases overall stroke risk
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/8/2017)... Feb. 7, 2017 Report Highlights ... The global synthetic-biology market ... billion by 2021, growing at a compound annual growth rate ... overview of the global markets for synthetic biology. - Analyses ... 2016, and projections of compound annual growth rates (CAGRs) through ...
(Date:2/7/2017)... BEACH, New York , February 7, 2017 /PRNewswire/ ... known as ID Global Solutions Corporation [OTC: IDGS], ("Ipsidy" ... identity management and electronic transaction processing services, is pleased ... reorganization of the Company. Effective January 31, ... of the Board of Directors, CEO and President.  An ...
(Date:2/2/2017)... , Feb. 2, 2017  EyeLock LLC, a ... a new white paper " What You Should Know ... problem of ensuring user authenticity is a growing concern. ... authentication of users. However, traditional authentication schemes such as ... Biometric authentication offers an elegant solution to ...
Breaking Biology News(10 mins):
(Date:2/24/2017)... Pa., Feb. 24, 2017  VWR Corporation (NASDAQ: VWR), the ... laboratory and production customers, today reported its financial results for ... Highlights: 4Q16 record quarterly ... 1.0% on an organic basis. ... an organic basis, while the Americas net sales increased 2.5%, ...
(Date:2/23/2017)... LONDON and NEW YORK ... at HIMSS, Lumeon , a leading digital ... (DN Telehealth), a provider of telemedicine and remote ... care pathways for telemedicine reimbursements.  ... and their patients, in real-time, extending consultations beyond ...
(Date:2/23/2017)... (PRWEB) , ... February 23, 2017 , ... ... Drug Discovery Services portfolio to include an array of biochemical analyses critical ... reliable data to drive their hit-to-lead and SAR programs, including inhibitor potency and ...
(Date:2/23/2017)... 2017  MIODx announced today that it has ... technologies from the University of California, San Francisco ... monitor a patient for response to immune checkpoint ... second license extends the technology with a method ... have an immune-related adverse event (IRAE) from their ...
Breaking Biology Technology: