Saturday, March 03, 2007

 

Scientists say Climate Change caused Neanderthal extinction in Iberia

Summary:

Recent studies carried out in Gorham's cave*, on Gibraltar, proved to be definitive for this work.

Results show that the Neanderthal extinction could have been greatly determined by environmental and climate changes and not by competitiveness with modern humans.

The research work has been published in Quaternary Science Reviews journal.

Main Text

Climate - and not modern humans - was the cause of the Neanderthal extinction in the Iberian Peninsula (Cave Art). Such is the conclusion of the University of Granada research group RNM 179 - Mineralogy and Geochemistry of sedimentary and metamorphic environments, headed by professor Miguel Ortega Huertas and whose members Francisco Jose Jimenez Espejo, Francisca Martínez Ruiz and David Gallego Torres work jointly at the department of Mineralogy and Petrology of the University of Granada (Universidad de Granada) and the Andalusian Regional Institute of Earth Sciences (CSIC-UGR).

Together with other scientists from the Gibraltar Museum, Stanford University and the Japan Marine Science and Technology Center (JAMSTEC), the Spanish scientists published in the scientific journal Quaternary Science Reviews an innovative work representing a considerable step forward in the knowledge of human ancestral history.

The results of this multidisciplinary research are an important contribution to the understanding of the Neanderthal extinction and the colonisation of the European continent by Homo Sapiens.

During the last Ice Age, the Iberian Peninsula was a refuge for Neanderthals, who had survived in local pockets during previous Ice Ages, bouncing back to Europe when weather conditions improved.

Climate reconstructions

The study is based upon climate reconstructions elaborated from marine records and using the experience of Spanish and international research groups on Western Mediterranean paleoceanography. The conclusions point out that Neanderthal populations did suffer fluctuations related to climate changes before the first Homo Sapiens arrived in the Iberian Peninsula. Cold, arid and highly variable climate was the least favourable weather for Neanderthals and 24,000 years ago they had to face the worst weather conditions in the last 250,000 years.

The most important about these data is that they differ from the current scientific paradigm which makes Homo Sapiens responsible for the Neanderthal extinction. This work is a contribution to a new scientific current - leaded by Dr. Clive Finlayson, from the Gibraltar Museum - according to which Neanderthal isolation and, possibly, extinction were due to environmental factors.

These studies on climate variability are part of the work of the group RNM 179, funded by the excellence project RNM 0432 of the Andalusian Regional Government's Department for Innovation, Science and Business and by the MARCAL project of the Spanish Ministry of Education and Science, both linked to the Andalusian Environment Centre (CEAMA - Centro Andaluz de Medio Ambiente).

Source (adapted): University of Granada PR "Spanish scientists point at climate changes as the cause of the Neanderthal extinction in the Iberian Peninsula" February 25 2007 [alt. Neandertal, Neandertals]

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[1] Based on the paper:

Climate forcing and Neanderthal extinction in Southern Iberia: insights from a multiproxy marine record

Francisco J. Jimenez-Espejo, Francisca Martínez-Ruiz, Clive Finlayson, Adina Paytan, Tatsuhiko Sakamoto, Miguel Ortega-Huertas, Geraldine Finlayson, Koichi Iijima, David Gallego-Torres and Darren Fa

Quaternary Science Reviews (Article in Press)
doi:10.1016/j.quascirev.2006.12.013

Paleoclimate records from the western Mediterranean have been used to further understand the role of climatic changes in the replacement of archaic human populations inhabiting South Iberia. Marine sediments from the Balearic basin (ODP Site 975) was analysed at high resolution to obtain both geochemical and mineralogical data. These data were compared with climate records from nearby areas. Baexcces was used to characterize marine productivity and then related to climatic variability. Since variations in productivity were the consequence of climatic oscillations, climate/productivity events have been established. Sedimentary regime, primary marine productivity and oxygen conditions at the time of population replacement were reconstructed by means of a multiproxy approach. Climatic/oceanographic variations correlate well with Homo spatial and occupational patterns in Southern Iberia. It was found that low ventilation (U/Th), high river supply (Mg/Al), low aridity (Zr/Al) and low values of Baexcess coefficient of variation, may be linked with Neanderthal hospitable conditions. We attempt to support recent findings which claim that Neanderthals populations continued to inhabit southern Iberia between 30 and approx 28 ky cal BP and that this persistence was due to the specific characteristics of South Iberian climatic refugia. Comparisons of our data with other marine and continental records appear to indicate that conditions in South Iberia were highly inhospitable approx 24 ky cal BP. Thus, it is proposed that the final disappearance of Neanderthals in this region could be linked with these extreme conditions.

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*History of Gorham's Cave

[Spain, Anthropology, Archaeology]

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Recent posts include:

"Birth rate, competition are major players in hominid extinctions"

"Skull suggests human-Neanderthal link"

"Earliest Evidence Of Modern Humans In Europe Discovered By International Team"

"Neanderthals and humans lived side by side: Gorham's Cave, Gibraltar (September 2006)"

"Research News: Neanderthal Genome Sequencing Yields Surprising Results"

"Did Interbreeding Between Humans and Neanderthals Lead to a Bigger Human Brain?"

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Comments:
the concern of scientists about the climate change in neanderthal extinction in lberia is genuine. The problem of pollution is one of the factor of changing such climate. Recent studies done in Gorham's cave proved to be definitive for this work.


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