How fast science progresses!
Not long ago we weren't even sure how and where Neanderthals fitted in the human family tree. Were they ancestors of modern Europeans? Were they just a regional variant; a subspecies; a different species entirely? Did they or could they interbreed with modern humans?
Now most of those questions have been answered with some degree of confidence, and not a few surprises, thanks to DNA analysis, and we're just left with questions about how, why and exactly when anatomically modern humans replaced Neanderthals across western Eurasia.
Was it our superior technology? Hardly. We both used stone tools and hunted with spears. Was it our higher intelligence? Our brains are actually smaller but maybe organised differently, so maybe we could learn and adapt more quickly? Was it a better social organisation? Neanderthals seem to have lived in small, relatively isolated family groups in which incestuous breeding was common if not normal. Did this lead to genetic weaknesses accumulating? Did it mean hunting large game was more difficult with fewer numbers?
Did modern human migrants into western Eurasia bring dogs that gave them a competitive edge? Or did we simply eat a wider range of food, including plants, that meant we could be more flexible and less prone to the loss of a prey species like mammoths?
It's this last question that this Scientific Reports paper addresses and which the authors believe refutes. It was written by an international team led by Prof. Dr. Hervé Bocherens and Dr. Dorothée Drucke of the Senckenberg Centre for Human Evolution and Palaeoenvironment (HEP) at the University of Tübingen, Germany by studying the oldest known fossils from the Buran Kaya caves on the Crimean Peninsula in the Ukraine.
Current map of Europe with the location of Buran Kaya III site and Emine-Bair-Khosar cave in the Crimean Peninsula. Map designed by S. Puaud using open access NASA resources at http://eoimages.gsfc.nasa.gov/images/imagerecords/73000/73580/world.topo.bathy.200401.3×21600×21600.C1.jpg |
Abstract
Relatively high 15N abundances in bone collagen of early anatomically modern humans in Europe have often been interpreted as a specific consumption of freshwater resources, even if mammoth is an alternative high 15N prey. At Buran-Kaya III, access to associated fauna in a secured archaeological context and application of recently developed isotopic analyses of individuals amino acids offer the opportunity to further examine this hypothesis. The site of Buran-Kaya III is located in south Crimea and has provided a rich archaeological sequence including two Upper Palaeolithic layers, from which human fossils were retrieved and directly dated as from 37.8 to 33.1 ka cal BP. Results from bulk collagen of three human remains suggests the consumption of a high 15N prey besides the contribution of saiga, red deer, horse and hare, whose butchered remains were present at the site. In contrast to bulk collagen, phenylalanine and glutamic acid 15N abundances reflect not only animal but also plant protein contributions to omnivorous diet, and allow disentangling aquatic from terrestrial resource consumption. The inferred human trophic position values point to terrestrial-based diet, meaning a significant contribution of mammoth meat, in addition to a clear intake of plant protein.
Dorothée G. Drucker, Yuichi I. Naito, Stéphane Péan, Sandrine Prat, Laurent Crépin, Yoshito Chikaraishi, Naohiko Ohkouchi, Simon Puaud, Martina Lázničková-Galetová, Marylène Patou-Mathis, Aleksandr Yanevich, Hervé Bocherens.
Isotopic analyses suggest mammoth and plant in the diet of the oldest anatomically modern humans from far southeast Europe.
Scientific Reports, 2017; 7 (1) DOI: 10.1038/s41598-017-07065-3
© 2017 The authors.
Published open access.
Reprinted under a Creative Commons Attribution 4.0 International Licence (CC-BY 4.0)
Anatomically modern humans entered Europe about 43,000 years ago and within about 3,000 years seem to have replaced the Neanderthals that had lived there for some 250,000 years. By analysing the ratio of the 15N isotope in specific amino acids from anatomically modern humans, and local prey species such as Saiga, horses, and deer, the team were able to determine that the major source of the amino acids in 15N in early human protein was in fact mammoth meat, not fish as had previously been assumed.
Although modern humans probably had more vegetables in their diet, in fact the two species of humans were in direct competition for the same food resource, so it seems likely that it was a simple competition for the same resource that led to the demise of Neanderthals. Exactly what it was that gave modern humans the competitive edge still remains to be answered.
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