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Wednesday, July 15, 2009

The Last Supper

The Last Supper Of The Hominids Establishes The Times They Lived At
The Sites


ScienceDaily (July 14, 2009) — In the French cave of Arago, an
international team of scientists has analyzed the dental wear of the
fossils of herbivorous animals hunted by Homo heidelbergensis. It is
the first time that an analytical method has allowed the establishment
of the length of human occupations at archaeological sites. The key is
the last food that these hominids consumed.


For many years, the mobility of the groups of hominids and how long
they spent in caves or outdoors has been a subject of discussion among
scientists. Now, an international team headed by researchers from the
Catalan Institute of Human Paleoecology and Social Evolution (IPHES)
in Tarragona has based its studies on the dental fossils of animals
hunted by hominids in order to determine the vegetation in the
environment and the way of life of Homo heidelbergensis.


Florent Rivals is the main author and a researcher from the Catalan
Institute for Research and Advanced Studies (ICREA), attached to the
IPHES in Tarragona. "For the first time, a method has been put forward
which allows us to establish the relative length of the human
occupations at archaeological sites as, up until now, it was difficult
to ascertain the difference between, for example, a single long-term
occupation and a succession of shorter seasonal occupations in the
same place", he explained to SINC.


In the study, recently published in the Journal of Human Evolution,
the researchers analyze the dental wear of the ungulates (herbivorous
mammals) caused by microscopic particles of opaline silica in plants.
These marks appear when eating takes place and erase the previous
ones. This is why they are so useful.


Thanks to the "last supper phenomenon", the scientists have been able
to analyze the last food consumed by animals such as the Eurasian wild
horse (Equus ferus), the mouflon (Ovis ammon antiqua) and the reindeer
(Rangifer tarandus). "This method allows us to confirm the seasonal
nature of the occupation", Rivals added. According to the team, the
microwear of the teeth is sensitive to seasonal changes in the diet.


The application has allowed the researchers to estimate the length of
the occupation of the site from the Lower Paleolithic Age in the cave
of Arago (France) by the number of marks on the fossils and,
therefore, the variation in the diet of several species of herbivores,
as "each season presented food resources which were limited and
different in the environment", the paleontologist clarified.


High and low periods of occupation


After confirming the hypothesis in present-day animals whose age and
date of death was known to the scientists, the researchers
demonstrated that, if a group of animals is seen during a specific
season (a short-term occupation), the signs of dental wear undergo
little variation. But if the occupation lasts several seasons, the
dental marks are more diverse.


"If the animals are hunted during long periods of occupation, more
variable dental wear would be expected", Rivals declared. In the case
of the French cave of Arago, the study of the dental wear confirms
that it was occupied in different ways. "With this method, we were
able to prove that at the site, which belonged to Homo
heidelbergensis, there is evidence of differing mobility, as there
were highly mobile groups and others with little mobility", the
scientist confirmed.


The Spanish and German researchers have combined this application with
multidisciplinary studies of archaeological sites in order to apply it
to other settlements of the Mid-Paleolithic Age such as Payre
(France), Taubach (Germany) and Abric Romani (Spain).


Journal reference:


1. Rivals et al. A new application of dental wear analyses:
estimation of duration of hominid occupations in archaeological
localities. Journal of Human Evolution, 2009; 56 (4): 329 DOI: 10.1016/
j.jhevol.2008.11.005





The abstract


Journal of Human Evolution
Volume 56, Issue 4, April 2009, Pages 329-339


A new application of dental wear analyses: estimation of duration of
hominid occupations in archaeological localities
Purchase the full-text article


References and further reading may be available for this article. To
view references and further reading you must purchase this article.


Florent Rivalsa, Corresponding Author Contact Information, E-mail The
Corresponding Author, Ellen Schulzb and Thomas M. Kaiserb


aICREA and Institut Català de Paleoecologia Humana i Evolució Social
(IPHES), Universitat Rovira i Virgili, Plaça Imperial Tarraco 1, 43005
Tarragona, Spain


bBiozentrum Grindel and Zoological Museum, University of Hamburg,
Martin-Luther-King-Platz 3, 20146 Hamburg, Germany


Received 10 January 2008;
accepted 10 November 2008.
Available online 9 April 2009.


Abstract


Characterization of settlement patterns is one of the core concepts in
archeological research. The duration of an occupation is usually
estimated through zooarchaeology (e.g., density of remains,
cementochronology) and is limited by taphonomic processes and sample
size. We propose a new application of dental wear methods for
estimating the relative duration of hominid settlements in Paleolithic
sites. Dental microwear is known to be sensitive to seasonal changes
in diet. In this new application we use microwear scratch counts to
estimate the variation in the dietary signal of various ungulate
species. We propose that this variation is correlated to the duration
of site occupation. Each season presents a limited and different set
of food resources available in the environment. If animals are sampled
only during a specific season (i.e., during a short term occupation)
then they would be expected to have a dental wear signal with little
variation. On the other hand, a greater diversity of food is available
across different seasons. Therefore, if game animals are hunted
through various seasons during long occupation periods, then they
would be expected to have more variable dental wear. The application
of this technique to the Middle Paleolithic site of Arago Cave
(France), where various types of occupations occurred, supports this
hypothesis. When combined with multidisciplinary studies of
archaeological localities (seasonality in particular), this new
application of dental wear analysis presents valuable information
about hominid settlements and behavior. We contextualize our data with
results from lithic and zooarchaeological analyses from Arago. These
results reveal the presence of both high and low mobility groups of
Homo heidelbergensis throughout the sequence of the Arago Cave.


Keywords: Microwear; Mesowear; Zooarchaeology; Human behavior;
Settlement pattern; Variability
Article Outline


Introduction
Materials


The modern samples from the Kaminuriak population of free-ranging
caribou
The fossil samples from Arago Cave


Methods


Selection and molding process of the teeth
Dental mesowear
Dental microwear
Statistics


Results


Microwear variation in extant ungulates (testing Hypothesis 1)
Variability and climatic factors (testing Hypothesis 2)
Variability and duration of occupation (testing Hypothesis 3)


Discussion


Variation in modern ungulates (Hypothesis 1)
Variability and climatic factors (Hypothesis 2)
Variability and duration of occupation (Hypothesis 3)
Implications for hominid behavioral ecology at Arago Cave


Conclusion
Acknowledgements
References

Source 1
Source 2
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