Monkey teeth help reveal Neanderthal weaning

Monkey teeth help reveal Neanderthal weaning

A team of U.S. and Australian researchers reports in the journal Nature May 22 that they can now use fossil teeth to calculate when a Neanderthal baby was weaned. The new technique is based in part on knowledge gained from studies of teeth from human infants and from monkeys at the California National Primate Research Center at the University of California, Davis.

Using the new technique, the researchers concluded that at least one Neanderthal baby was weaned at much the same age as most modern humans.

Just as tree rings record the environment in which a tree grew, traces of barium in the layers of a primate tooth can tell the story of when an infant was exclusively milk-fed, when supplemental food started, and at what age it was weaned, said Katie Hinde, professor of human evolutionary biology at Harvard University and an affiliate scientist at the UC Davis Primate Center. Hinde directs the Comparative Lactation Laboratory at Harvard and has conducted a three-year study of lactation, weaning and behavior among rhesus macaques at UC Davis.

The team was able to determine exact timing of birth, when the infant was fed exclusively on mother's milk, and the weaning process, from mineral traces in teeth. By studying monkey teeth and comparing them to center records, they could show that the technique was accurate almost to the day.

After validating the technique with monkeys, the scientists applied it to human teeth and a Neanderthal tooth. They found that the Neanderthal baby was fed exclusively on mother's milk for seven months, followed by seven months of supplementation -- a similar pattern to present-day humans. The technique opens up extensive opportunities to further investigate lactation in fossils and museum collections of primate teeth.

Although there is some variation among human cultures, the accelerated transition to foods other than mother's milk is thought to have emerged in our ancestral history due, in part, to more cooperative infant care and access to a more nutritious diet, Hinde said. Shorter lactation periods could mean shorter gaps between pregnancies and a higher rate of reproduction. However, there has been much debate about when our ancestors evolved accelerated weaning.

For the past few decades researchers have relied on tooth eruption age as a direct proxy for weaning age. Yet recent investigations of wild chimpanzees have shown that the first molar eruption occurs toward the end of weaning.

"By applying these new techniques to primate teeth in museum collections, we can more precisely assess maternal investment across individuals within species, as well as life history evolution among species," Hinde said.

Authors in addition to Hinde were: Christine Austin and Manish Arora, Icahn School of Medicine at Mount Sinai, New York, Harvard School of Public Health, and University of Sydney, Australia; Tanya Smith, Harvard University; Asa Bradman and Brenda Eskenazi, UC Berkeley; Renaud Joannes-Boyau, Southern Cross University, Lismore, Australia; David Bishop, Dominic Hare and Philip Doble, University of Technology Sydney, Australia.

The work was funded by the U.S. Environmental Protection Agency, U.S. National Institute of Environmental Health Sciences, U.S. National Science Foundation, Australian National Health and Medical Research Council, Australian Research Council and Harvard University.

Welcome to SUV System Ltd!

SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.

We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.

SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com

Electronic Components distributor:http://www.suvsystem.com

Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html

IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html

LED Distributor:http://www.suvsystem.com/l/LED-1.html

Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html

Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html

Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html

Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html

SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc

we are focus on the following fields,and hope we can help you.

CS5331A-DSZNRND CS5331A-BSR CS5331A-BS CS5330A-KSZRNRND CS5330A-KSZNRND CS5330A-KS CS5330A-BSR CS5330A-BS CS5322-BLZR CS5322-BLZ CS5322-BLR CS5322-BL CS5321-BLZR CS5321-BLZEndofLife CS5321-BLR CS5368-DQZ CS5368-CQZR CS5368-CQZ CS5366-DQZR CS5366-DQZ CS5366-CQZR CS5366-CQZ CS5364-DQZR CS5364-DQZ CS5364-CQZR CS5364-CQZ CS5363-DZZR CS5363-DZZ CS5361-KZZR CS5361-KZZ CS5361-KSZR CS5361-KSZ CS5361-DZZR CS5361-DZZ CS5360-KSREnd of Life CS5360-KSR CS5360-KSNRND CS5360-BSREnd of Life CS5360-BSR CS5360-BSNRND
http://www.suvsystem.com/a/1563.aspx