# Environmental Changes and Cultural Transitions in SW Iberia during the Early-Mid Holocene
## 1 Introduction  
The Early-Mid Holocene period is characterized by several environmental changes, such as the postglacial marine transgression, an increase of temperatures, and the existence of diverse episodes of ice-rafted debris in the North Atlantic Ocean. Littoral areas suffered a rapid transformation resulting from the inundation of the fluvial valleys and the progressive development of diverse coastal features. From a different perspective, the vegetation adapted to the new climatic-edaphic conditions and reacted to abrupt episodes, the so called Bond events, which are associated to dry conditions in the Mediterranean region [1]. However, the Early-Mid Holocene was not only defined by unique environmental changes, but by important cultural transformations within hunter-gatherer groups and the adoption of new subsistence strategies.  
The process of neolithization in Southwestern Iberia is controversially disputed and different theories attempt to explain its origin. Some authors interpret it as a maritime pioneer colonisation of depopulated regions by Neolithic groups from the Western Mediterranean [2], while others propose indigenous origins defined by the continuity of localMesolithic groups in certain regions [3], suggesting that the beginnings of agriculture could have had an autochthonous nature [4]. Many authors consider that the area of Andalusia, the Algarve, and the Moroccan Atlantic fringe have shared similar traits during this process [5], which would explain the existence of Neolithic \"enclaves\" with specific regional features [6] or a southern neolithization route along the North African coast [7; 8]. The inherently intricate interpretation of such a complex process is, in this case, weighed down by the lack of absolute datings in clear stratigraphic sequences, and the absence of information regarding the Mesolithic period at a regional scale [9].  
Recent palaeogenetic studies have shed light on this complicated situation, confirming that Southern Iberian Neolithic humans share the same genetic composition as the Cardial Mediterranean culture that reached Iberia _ca._ 7.5 ka BP [10]. These early Neolithic Iberian groups present genetic differences with the early Neolithic central European farmers, pointing toward two different migrations and linking all Neolithic Iberians with the first migrants that arrived with the initial Mediterranean Neolithic wave of expansion [11]. It is evident that these Iberians mixed with local hunter-gatherers, maintaining and thus expanding their subsistence strategies. However, it is assumed that this process was not homogeneous and the introduction of new elements, such as food production techniques, can hardly be dissociated from the heterogenous geography, the environmental diversity, and the influence of local groups. Therefore, further research is needed to explain differences in both Mesolithic and Neolithic cultures at the regional scale, as well as to complete the complex environmental puzzle of this area.  
Studies integrating archaeological and palaeenvironmental data from a long-term perspective can provide a critical framework to examine the resilience of human groups to past and current global changes. Thus, this work focuses on the palaeenvironmental reconstruction of the southwestern Iberian littoral area, with special focus on the occidental Algarve coast, in the course of the Mesolithic and Neolithic periods. We contribute with a new environmental dataset of palynological and geochemical data to discuss and define changes in the vegetation, reconstructing coastal landscapes, and understanding how human groups adapted to these transformations.