Wednesday, October 12, 2016

Environmental Changes in the Balearic Islands (Burjachs et al, 2016)

As surprising as this may be, the Balearic Islands were unoccupied until around 2,200 B.C.  If before this, then it must have been an almost invisibly small population.

In essence, it is at the cusp of the Beaker period that humans begin occupying the islands and very quickly a number of its weird native animals suddenly go extinct and massive soil erosion begins taking place.  It is within this frame that it was speculated (maybe Waldren?) that people with a Beaker identity were responsible, as I believed due to slash and burn agricultural practices.

At least from the abstract, this process was independent of human activity and began occurring before human occupation and those climatic factors are almost totally responsible.  Maybe there is a combination of climate change that is exasperated by human activity.

Overview of environmental changes and human colonization in the Balearic Islands (Western Mediterranean) and their impacts on vegetation composition during the Holocene

Francesc Burjachs, , Ramon Pérez-Obiol, , Llorenç Picornell-Gelabert, , Jordi Revelles, , Gabriel Servera-Vives, , Isabel Expósito, , Errikarta-Imanol Yll,
(2016) Journal of Archaeological Science


According to radiometric dates and the current state of research, the Balearic Islands were not colonized by humans prior to c. 4420/4220 cal yr BP. Therefore, it is possible to know the natural evolution of the landscape of the Balearic Islands for the first two-thirds of the Holocene (c. 10,000 to c. 4300 cal yr BP). This study aims to improve our understanding of the respective roles of human societies and/or climate in the transformation of vegetation cover during the Late Holocene in this Western Mediterranean archipelago. The results show the importance and control of climate oscillations in the evolution of vegetation throughout the Early and Middle Holocene. Our data clearly show that the transformation of the landscape started before the first human settlements. In Minorca (north-eastern Gymnesian Islands), this upheaval occurred between 5825 and 4675 cal yr BP (fourth to third millennium BC), while in Majorca (the largest of the Gymnesian Islands) the transition is less well dated, oscillating between 7169 and 2535 cal yr BP. In the southern Pityusic Islands, observed changes in Ibiza are less pronounced and coincide with the 4.2 cal kyr BP climate event, synchronous with human colonization. The correlation between forest fires and rapid climate events, as well as the resilience of vegetation until the Middle Ages (tenth century) in Ibiza, suggest that the evolution of climatic conditions is the preponderant parameter for explaining Holocene vegetation changes on these islands.


  1. So the authors are absolutely sure they have found the evidence for the very first occupation of the islands. Amazing. Did it occur to them that humans may have been responsible for much of the resulting climate change?

    1. If I can get a copy of the paper I'll look for their discussion on the topic. The first occupation evidence comes from radiocarbon dates of those materials. I'm somewhat skeptical the islands were inhabited this late just based on a lack of evidence.

    2. Pontic Greeks from Giresun descend from Sinope colonists and Sinope was colonised by Ionians from Miletus. Is interesting to note that there exist an Ionian colony known as Pityussa just like the known Greek name for Eivissa Pityuses. In Eivissa, where is found the famous bust of Demeter that have been confused with the punic Tanit for decades, is known the cult to Demeter. The bust belonging to Demeter have been analysed and is found to contains black particles of volcanic sand origin from the Etna, is thought to be made in Sicily with red clays typical of the eastern Trinacria, which was colonized by the Ionians. The Ionians could be arrived to Eivissa c.2700 YBP. This lineage could be an Ionian marker. T1a1 formed 17,400-14,600 BP, is the largest lineage downstream from T1a-M70 and became widespread across Eurasia and Africa before the modern era.

      This extremely rare subclade has been found in Ibizan (Eivissan) islanders and Pontic Greeks from Giresun. The first Y-STR haplotype belonging to this lineage appeared in the paper of Tomas et al in 2006 among a sample of Eivissan individuals but is not until August 2009 when the first T1a1-L162(xL208) individual was reported

  2. Thanks. Yes, the dates do seem rather unexpectedly recent considering humans had reached some other relatively remote islands in the Mediterranean many years earlier. But this is not the first time I've seen the fact that the last evidence for presence of extinct species is a few years before the first evidence for humans as evidence humans didn't cause the extinction. Not very reliable evidence as far as I'm concerned, especially the remark: " In the southern Pityusic Islands, observed changes in Ibiza are less pronounced and coincide with the 4.2 cal kyr BP climate event, synchronous with human colonization". Seems some are reluctant to admit humans have long been responsible for environmental change.