Friday, March 27, 2015
YOLO COUNTY NEWS
99 CENTS

Monkey teeth a window to neanderthal weaning

By
From page A11 | May 26, 2013 |

A monkey mother and infant at the UC Davis Primate Center west of Davis.    Kathy West, UC Davis/Courtesy photo

Most modern human mothers wean their babies much earlier than our closest primate relatives. But what about our extinct relatives, the Neanderthals?

A team of U.S. and Australian researchers reports in the journal Nature on 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 UC 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 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 UCD.

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.

— UC Davis News Service

Comments

comments

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • .

    News

    Anti-gay initiative puts AG in a bind

    By The Associated Press | From Page: A1

     
    County supervisors consider options for historic courthouse

    By Anne Ternus-Bellamy | From Page: A1 | Gallery

     
    State loosens sex offender residency restrictions

    By The Associated Press | From Page: A1

    Need a new best friend?

    By Enterprise staff | From Page: A3 | Gallery

     
    Lawyer disputes police’s hoax claim in California kidnapping

    By The Associated Press | From Page: A3

     
    Davis Flower Arrangers meet Wednesday

    By Enterprise staff | From Page: A4

    Sign up for Camp Shakespeare

    By Enterprise staff | From Page: A4

     
    Empower Yolo offers peer counselor training

    By Special to The Enterprise | From Page: A4

    Sing along on April Fool’s Day

    By Special to The Enterprise | From Page: A5

     
    Neighbors invited to adopt Willow Creek Park

    By Special to The Enterprise | From Page: A5

    .

    Forum

    Blame Reid for impasse

    By Letters to the Editor | From Page: A7

     
    Practice cancer prevention each day

    By Special to The Enterprise | From Page: A7

     
    Turnabout is fair play

    By Letters to the Editor | From Page: A7

    Be aware and be afraid

    By Letters to the Editor | From Page: A7

     
    .

    Sports

    UCD’s Hawkins, Harris to shoot at Final Four

    By Enterprise staff | From Page: B1 | Gallery

     
    Home sweet home: Aggie women win a tennis match

    By Enterprise staff | From Page: B1

    Devil boys grind out a net win at Franklin

    By Enterprise staff | From Page: B1

     
    DHS baseballers fall to Vintage in eight innings

    By Enterprise staff | From Page: B1

    UCD men edge Hawaii on the court

    By Enterprise staff | From Page: B1

     
    DYSA roundup: Recent youth softball games feature big hitting

    By Enterprise staff | From Page: B2 | Gallery

    Sacramento get its second straight win

    By The Associated Press | From Page: B2

     
    Sharks get a key win over Detroit

    By The Associated Press | From Page: B10 | Gallery

     
    .

    Features

    .

    Arts

    UCD Student Fashion Association presents charity fashion show

    By Special to The Enterprise | From Page: A3

     
    ‘Get Hard’ comes across as rather limp

    By Derrick Bang | From Page: A8 | Gallery

    Monticello announces April live-music shows

    By Enterprise staff | From Page: A9

     
    Leonardo Tuchman’s work shows at UC Davis Craft Center Gallery

    By Special to The Enterprise | From Page: A9

    Sacramento Youth Symphony holding open auditions

    By Special to The Enterprise | From Page: A9

     
    Preview Art Studio Tour participants’ work at The Artery

    By Enterprise staff | From Page: A9 | Gallery

    Smokey Brights to perform at Sophia’s

    By Enterprise staff | From Page: A9

     
    ‘Deserted Destinations’ is April exhibit at Gallery 625

    By Special to The Enterprise | From Page: A9 | Gallery

    .

    Business

    Camry Hybrid takes a step forward

    By Ann M. Job | From Page: B3

     
    .

    Obituaries

    Celebrate Rusty Jordan’s Life

    By Creator | From Page: A4

     
    .

    Comics

    Comics: Friday, March 27, 2015

    By Creator | From Page: B4