Navigation Links
Neanderthal teeth grew no faster than comparable modern humans'

Recent research suggested that ancient Neanderthals might have had an accelerated childhood compared to that of modern humans but that seems flawed, based on a new assessment by researchers from Ohio State University and the University of Newcastle .

They found that the rate of tooth growth present in the Neanderthal fossils they examined was comparable to that of three different populations of modern humans.

And since the rate of tooth growth has become a more-accepted tool for estimating the length of childhood among hominids, the finding is the latest evidence suggesting that Neanderthals may not have been as different from modern humans as some researchers have thought.

The study by Debbie Guatelli-Steinberg, assistant professor of anthropology at Ohio State , appeared in the current issue of the Proceedings of the National Academy of Sciences. Donald J. Reid, lecturer in oral biology at the University of Newcastle , Thomas A. Bishop, associate professor of statistics, and Clark Larsen, professor and chair of anthropology, both at Ohio State , were co-authors in the study.

"Based on our study of the enamel of these Neanderthal teeth and other modern ones, we can't support the claim that Neanderthals grew up more quickly than do modern humans," she said.

Key to this conclusion are microscopic lines on the outside of teeth that mark the incremental growth of enamel on a young tooth. Like tree rings that can gauge the age of a redwood, these striations ?called perikymata ?record new growth on the surface of the tooth.

Researchers know from earlier work that these markings are present in all forming teeth, signifying six to 12 days of growth. By multiplying that interval by the number of perikymata on a tooth's surface, researchers can gauge how long it took for the tooth to mature. And that gives them an indication of the length of an individual's childhood.

Neanderthals, Homo neanderthalensis, were the dominant hominid inhabiting most of what is now Europe and western Asia . Remains have been found as far south as Iraq and as far north as Great Britain . Fossil skulls reveal the distinctively prominent brows and missing chins that set them apart from later humans.

They thrived from about 150,000 to 30,000 years ago until their lineage failed for as-yet unknown reasons. Most researchers have argued that their life in extremely harsh, Ice Age-like environments, coupled with their limited technological skills, ultimately led to their demise.

In a study published last year in the journal Nature, other researchers contended that Neanderthal teeth took 15 percent less time to reach maturity than those in later Homo sapiens, suggesting to them that a Neanderthal childhood would be shorter than our own.

But Guatelli-Steinberg's team wanted a broader comparison and therefore compared the teeth from Neanderthals to those of three modern populations ?people currently living in Newcastle-upon-Tyne , U.K. ; indigenous people from southern Africa, and Inuit from Alaska dating from 500 B.C. until the present.

"We chose these three groups since they would provide a good cross-section of various populations from different regions of the world," she said. "We feel that they give us some insights into the variation that exists within modern humans."

For the study, the researchers used precise dental impressions Guatelli-Steinberg and Larsen made of 55 teeth believed to come from 30 Neanderthal individuals. These were compared to 65 teeth from 17 Inuit, 134 teeth from 114 southern Africans and 115 teeth from as many Newcastle residents. In all cases, the researchers tallied the number of perikymata on the enamel surface of the teeth.

Guatelli-Steinberg said that the results showed that the enamel formation times for the Neanderthals fell easily within the range of time shown by teeth from the three modern populations ?a conclusion that did not support a shorter childhood for the Neanderthals.

Enticing though it may be, these new findings haven't convinced the researchers that a Neanderthal childhood was equal to a modern human's.

"The missing key bit of data to show that would be evidence for when the first molar tooth erupted in the Neanderthals, and we simple have no evidence of when that occurred," she said.

The length of time is important, the researchers say, because unlike all other primates, humans have an extended period of childhood growth, during which brain matures both in size and through experiences. Some earlier hominids matured far more quickly than modern humans.

"The question is when exactly did that pattern of development evolve in the growth of humans," she said.


Source:Ohio State University

Related biology news :

1. Genetic study of Neanderthal DNA reveals early split between humans and Neanderthals
2. Climate change was the cause of Neanderthal extinction in the Iberian Peninsula
3. Nanospheres that block pain of sensitive teeth
4. Birds that make teeth
5. Tetracycline plus teeth equal gray smile
6. Ultrasound may help regrow teeth
7. Quantum dots provide a faster, more sensitive method for detecting respiratory viral infections
8. Muscle repair: Making a good system better, faster; implications for aging, disease
9. Mosquito study shows new, faster way West Nile can spread
10. Clean skies=faster global warming?
11. Jefferson biologist coaxing human embryonic stem cells to make dopamine with simpler, faster method
Post Your Comments:

(Date:10/13/2015)... Research and Markets ( ) has announced the ... Market - Estimation & Forecast (2015-2020)" report to ... --> The biometric market value is anticipated to ... in 2020 at an estimated CAGR of 16.47% from ... . Growing digitization in the government sector is expected ...
(Date:10/12/2015)... -- NXTD ) ("NXT-ID" or the "Company"), a ... reports on the recent SNS Future in Review Conference in ... NXTD ) ("NXT-ID" or the "Company"), a biometric authentication company ... recent SNS Future in Review Conference in Park ... NXTD ) ("NXT-ID" or the "Company"), a biometric authentication ...
(Date:10/8/2015)... October 8, 2015 NXT-ID, ... "Company"), a biometric authentication company focused on the ... Wocket® smart wallet announces that revenues for the ... $410,000 compared with $113,00 for the three months ... months ended September 30, 2015 were approximately $520,000. ...
Breaking Biology News(10 mins):
(Date:10/13/2015)... ... ... Proove Biosciences, a commercial and research leader ... Medicine of the University of Southern California (USC) Pain Center to study ... Clinical Objectives Linking Genotypic and Phenotypic Association with Pain Outcomes) is one of ...
(Date:10/12/2015)... Calif. and BRUSSELS , Oct. ... (Euronext Brussels: UCB) today presented additional findings from an exploratory ... The findings were presented today in an oral plenary ... (ASBMR) 2015 Annual Meeting in Seattle . ... --> The small exploratory sub-study data showed ...
(Date:10/12/2015)... , Oct. 12, 2015 This report covers ... include cell type, products, applications, end-user markets and geographic ... HIGHLIGHTS The global cell expansion market generated revenue ... to reach revenues of $9.7 billion in 2015 and ... rate (CAGR) of 17.8% from 2015 to 2020. ...
(Date:10/12/2015)... octubre de 2015 El 8 de octubre, ... récord en el congreso con su declaración acerca del ... Plasma Awareness Week (IPAW), que se celebrará del 11 ... la Plasma Protein Therapeutics Association (PPTA) y ... , Aumentar la concienciación mundial acerca de la donación ...
Breaking Biology Technology: