Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Slowly-developing primates definitely not dim-witted

18.04.2008
Some primates have evolved big brains because their extra brainpower helps them live and reproduce longer, an advantage that outweighs the demands of extra years of growth and development they spend reaching adulthood, anthropologists from Duke University and the University of Zurich have concluded in a new study.

The four investigators compared key benchmarks in the development of 28 different primate species, ranging from humans living free of modern trappings in South American jungles to lemurs living in wild settings in Madagascar.

"This research focused specifically on the balance between the costs and benefits of growing a large brain," said Nancy Barrickman, a graduate student in Duke's Department of Biological Anthropology and Anatomy, who is first and corresponding author of a report now posted online for a future print edition of the Journal of Human Evolution.

"Growth rates are much slower in large-brained organisms, and that causes a delay in reproduction," Barrickman said. "If individuals wait too long to reach maturity then they run the risk of dying before they've had the chance to reproduce. So there must be some benefit to large brain size at the same time these costs are incurred.

... more about:
»Barrickman »ExtrA »Life »Skill »primate

"Is larger brain size causing life histories to become extended and slowed down? We think so," Barrickman added. "That obviously fits in very well with humans, who take forever to grow up and live a really long time. So we have the opportunity to have lots of offspring over that long period."

Barrickman drew these conclusions working with Carel van Schaik, a Duke adjunct professor on her doctoral studies committee who directs the University of Zurich's Anthropological Institute and Museum. Other coauthors include Duke graduate student Meredith Bastian, and Karin Isler, a collaborator of van Schaik's in Switzerland.

"Our main finding is that brain size is a far better predictor of the duration of immaturity than body size, at least among primates," said van Schaik. "This study is also useful because it allows us to understand why humans develop so slowly and live so long -- we have no other choice!"

Other studies have linked primate brain size to life span and other factors, but those results have been contradictory, according to the new report. Previous studies were "polluted" by mixing data on captive and wild animals, van Schaik said. "Because development and survival are highly responsive to conditions, this variability made it impossible to do clean comparisons."

Their study was supported by the scientific research society Sigma Xi, the American Museum of Natural History and the Ruggles Gates Fund for Biological Anthropology in the United Kingdom.

Barrickman and her colleagues focused on primates living in the wild because "animals tend to grow up faster in captivity," she said. In the case of humans, they studied the Ache, a tropical forest culture in eastern Paraguay.

"Their food is exclusively wild food they forage from the forest," she said of the Ache. "And they don't have other things like modern birth control methods that you'd find in an industrial population like ours. My argument is that we're basically captive primates by comparison."

After analyzing available data on life history benchmarks such as length of pregnancy, years from birth to maturity, pre- and post-natal brain development and lifespan, the researchers found that humans and other big-brained species such as chimpanzees share certain survival traits.

It takes longer to grow a bigger brain, thus leaving immature offspring in need of extra care for longer periods. But larger brains also provide adult caretakers with "more complex foraging techniques, predator avoidance and social skills," the researchers wrote.

Greater skill allows adults to live longer, which in turn gives them longer reproductive lives. Humans have added to this adaptive advantage by using their cognitive and social skills to work together in providing shelter and nourishment for the young, they said.

Additionally, human females can live well beyond their reproductive years. And the contributions of non-reproducing grandmothers may further enhance their own children's reproductive effort and decrease infant mortality, Barrickman said. That's because grandmas offer extra assistance in child rearing and food gathering.

Studies of some primitive societies, such as the Hadza in East Africa, show that "grandchildren are more likely to survive if they have a grandmother present," she said.

Some studies suggest that starting life with a brain that is still developing itself confers some survival advantages to offspring, according to Barrickman. Extended interactions with mothers and their surroundings can help "wire their brain" as it grows, she said.

"They wind up with very plastic brains that can adjust to whatever environmental stimulations come at them," she said.

Monte Basgall | EurekAlert!
Further information:
http://www.duke.edu

Further reports about: Barrickman ExtrA Life Skill primate

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>