 thank the organizers for accepting our paper. It seems a little disconnected, at least geographically, very much disconnected with the rest of the papers. Even thematically, at least, it does too. So I appreciate also those who have stayed and make the effort to listen to this. I also must say that this is something we are trying to think about. So I was hoping it might get some interaction or suggestions or comments or critiques that can help us. We're trying to go along a path of social interpretation from some hard-to-gatherers context. So it's not an easy path, and probably I'm not sure if you like it actually. To make things even worse, Dr. Sabro just said that we should try to do it better and measure, and this is just qualitative thinking. So I mean, I'm in a pretty bad shape to start with. Having said that, let us start. I have to give you a little context. This is the study area we're working. This is the North Coast of Chile. This is the hyper-arid Atacama Desert, the most arid desert in the world, as you know. The coast is actually especially arid. You can see there eight millimeters presentation a year that's an average in the place we're working. Some areas can be even less than that. The area we're working, it's a very shallow coastal platform, flanked in the west by the Pacific Ocean, and on the east, only 500 meters of coastal platform, and then you have a coastal range of 2,000 meters above sea level. So you have a very shallow coastal platform where people actually live to this day. Most of the, actually, cities are there to this day. Due to the hyperaridity, you have a very low terrestrial biomass production, of course, in the terrestrial ecosystems, and you don't have any streams, permanent streams or rivers in this area. So the only sources of dependable water are small springs. But despite all these negative things I've told you about, this is one of the most productive marine ecosystems in the world. So this is just one picture to have you, can have an idea of the shallow platform, the small platform and the hyperaridity of the place. And this is an example of the water available for living in the area. So you can more or less understand what an extreme environment is. Despite of that, this environment has been inhabited for hunter-gatherers for 12,000 years. And this is one of the last example of hunter-gatherers recorded by Philippine in the late 19th century before they were absorbed by mining and therefore this lifeway disappeared. And when these people were observed in the 19th century, these hunter-gatherers were highly mobile and low demographic groups, highly mobile, which is probably the way to adjust to these environmental conditions. But this was not archeology shows, this was not the way these people lived throughout its history. And what I want to speak about now is present a very broad historical process in which in this environment, agglomeration practices took place and try to understand why they took place and finally to interpret the social implications that this transformation could have meant for the lifeways of these people. The organizers were saying in the morning in presentation that we should try to focus on understanding why agglomeration takes place. I'm separating here the why from the social implications. You will see why I'm doing this afterwards, but the social may not be the why, but maybe an implication or a conclusion of the why. If you didn't understand that, nevermind. This is a very broad, basic chronological structure. I want to show you very briefly the process that occurred from the early arc, what we call the archaic one towards the archaic three and four where these agglomerations occurred. Archaic five and six, this agglomeration, this occurs if I may invent that word. So the process is very simply, it has very basic characteristics. From the archaic one towards archaic two and three, one thing that you see in the archeological record is a clear transformation from a mixed economy exploiting terrestrial and marine resources to a very focalized and specialized marine economy. You see that in the archeology, in the archeofounder remains, you see almost only fish or basically fish in the archeofounder context of the archaic three and you see this also in the isotope even though we don't have a very big sample throughout the history of this period, all always individuals fall above the marine predators in the trophic chain so they are highly, most of the protein comes from marine foods. But this was not, we don't have individuals from the first period where archeofounder, as I told you, is more diverse. So there seems to be a process of orientation towards from a more mixed economy towards a very specialized marine economy. Another thing that I want to show you is this change in subsistence base is related, of course, to a change in technology that also from a very generalized technology you find the first period towards a very specialized technology in the local resources for extracting, gathering, keeping this on the left, you see we have good preservation because it's hyperarid so we have beautiful bags for the mollusks and everything that like woven or woolen or whatever. And it includes even boats and fishing and sea hunting of whales and of tuna fish, which was also, by the way, recording in some beautiful rock art that's depicted in the area. You see the whaling and nets there and so forth. So we have a specialized technology in the food. But what I want to focus on now, because this is the theme of the presentation, is that a third change that you can see in this historical process is from a very high residential mobility like the one observed by Europeans in the 17th and 16th century, you see from a high residential mobility to a low residential mobility, very low mobility and probably bigger demographic numbers. Archaeologically, you can see from, it's difficult to see, but you see deposits in this period, not even in this one, shallow deposits of hard and very small shell mines intercalated with a sterile deposit to more intensely dense shell mining deposits. And finally, you find this type of shell mining with almost no sterile material within it. All the soil there is just anthropogenically originated. By the way, I always tell, this is a picture of a profile excavated by Junius Burden in 1930s. So 80 years later, the profile is just as he left it. But you can see the huge size of the sites compared to what we had in previous periods. We have more amount of sites. We have bigger sites horizontally, bigger sites vertically, much more amount of ecofacts, artifacts. So we interpret this as a change towards low residential mobility. And at the end of the process, in the top, in the upper part of these huge mounds or in the lateral part of these huge mounds, we find the appearance of structures like the ones you see here. And these structures have below their floors, have burials. So people are burying, this is the first appearance of formal cementaries, agglutinated cemeteries in the sequence associated with this agglutinated and big. This is just examples of what I was telling you. Most of these have been looted so they're difficult to have. Actually, these are plants of the 1960s excavations. Today, they're mostly looted. This actually, this is a drawing from amateur archaeologists from the 1920s. Anyway, so if our interpretation is correct, that we find the process of agglomeration in the sense that people are living together longer period and more people living together in specific spaces, the question would be the first one, why? And I think the why question seems to be the most easy one to answer. And it has to be probably with environmental variables. For example, we have records of terrestrial environments. This is a publication recently by other colleagues but that shows that by the time we are finding these bigger sites appearing, you have find a very clear change, environmental change in different proxies from more wet conditions in the terrestrial environment towards drier conditions. And you see this as I told you in various and different types of proxies. That's what's happening in the terrestrial environment. In the coast, these are my co-authors, Karola Flores, the recent and yet unpublished data showing a change by isotopic analysis of the temperature, sea surface temperature and that also the moment that this changes, it's related to the change also in the settlement patterns. What it's interested in, regardless of the effects that this change would have had in the oceanographic conditions, it must have had an important effect on what we call the Kamanchaka. The Kamanchaka is associated with the lower sea surface temperature, more of these condensed clouds and these condensed clouds are the ones that form what we call the Lomas vegetations there. So that means rising the sea surface temperature means lower vegetation in the Lomas vegetation. And if that was not enough, we have evidence, this is the other colleagues or collaborators of ours work, evidence of a decrease. Before 5,000 ADC, we have no evidence of torrential rains or associate with the ENSO or the El Nino and therefore this data shows that most of the springs are fed by this type of torrential rain. So if we had no torrential rain during the early Holocene, that means most of these springs would have been also affected. So we have low dryness in the terrestrial environment, less Kamanchaka for less vegetation here and less springs. And as you know, ethnographically we know that for indecent areas for hunter-gatherers, water is the key element to structure mobility. If this was not enough, we know also that three levels were rising from the early Holocene to the middle Holocene. And this was probably the shoreline regardless of sectonic depth, I'm not going into the details, but this is probably when the area was first used, colonized, this was the shoreline. And this is now the shoreline and this is the shoreline that was available after 6,000 or 7,000 years ago when these big meanings start to appear. And actually, this is one example of that site, this is one example of that site. So we have a very important change in the environmental conditions that probably meant that people had to stick to the water availability. And at the same time, we have a very short, a shortage of space because space, I mean, you have to, this is the peak of Santander, the occupations are in the coastal plug. So that might be the why people are agglomerating. The question is, what does agglomeration mean socially? Because we just see that people are living together, but what does that mean? And here we come into an interpretive problem, how do we deal to and how do we begin to understand what this means socially? And I will speak about three things through which we're trying to understand what this process may have meant socially. But that's the question. First, sociality, interaction patterns. In the early Holocene, occupation, even though we don't know what's happening in the site that might be underwater, the residential occupations are occurring at many sites at the same time. All of these sites are small sites like this rock shelter. So that means that people occupying these sites, social units must have been small occupying these sites because of the space and dispersed because they are occupying many of these sites along the coast. Whereas in the middle Holocene, we see only the appearance of this site. Rock shelters are never again used or hardly used at this period. People are occupying open area sites and bigger sites and that means more people are fitting in that space and that could have implied more social interaction. Not only that, but you can see that around this big shelter, there are many sites, but they are only sites for processing, like foraging tours, processing resources, so there's no occupation here, no occupation in the rock shelters, no occupation in the Quebrada, to the rabbi, living to the work of the interior. You just see one project from there, one napping activity here, so they're using all this space, but just for activity, short time activity and they're dwelling in these big sites. There are no other dwelling places, so people are dwelling together in open area sites. So that means sociality may have been changing from this spatial pattern that we see. Memory, this is a difficult one. Even though they have short territory, you see one of the sites here, that doesn't mean that they couldn't dwell here or here or here or here. Yet, they are coming and dwelling again and again on the same space, even though I don't think it's there where it's necessarily obliged to do it. That meant that gradually, these shell mountains began to, of course, be built. At some point, I believe, people must have been aware that their occupation on this site, that they chose to occupy on top of their predecessors, was inscribed on the landscape because this mountain starts to be very clearly seen from away. So at some point, you see another example here, big mountain mount and another example here, very much eroded, you see the big shell mount there, that's a house that you can see more than the size of the place. At some point in history, these people were dwelling on top of their predecessors and inscribing their own history in landscape. So they're inscribing memory, more even more so when they start burying their dead below their own footpeat. So there's an intention of linking with the past, with making tradition in these spaces. That's the idea. And the last one, the idea of us and the separation from them. Junius Berg, these archaeologists in the 1940s, described for all these areas, he said these are what they called the shell fish hoop culture because they share the material culture from our study area towards Arica and even for the North. That's very similar, so they said this is one culture. But whereas in Arica, burials are used, probably, you know, this is the famous Chinchoromanus, the earliest modification in the world, artificially, they are very mummified. They're never mummified here. And whereas in Arica, the cemeteries are away from the dwelling, here, as we saw, people are living over the cemetery. So that means, of course, a very different, how do you say, funerary pattern. And that means that even those these people know each other, are related to each other, they are choosing to bury their dead separately, even knowing how the other one buried their dead. So I think this means that there's a knowledge, a sense of identity, a separation between them and us. So, even though the process of agglomeration may have been driven by environmental factors, mainly the limited dependable water sources, I think it's socially favored the formation of a particular sense of community, the idea of a community in this group. And this sense of community is significantly in this increased face-to-face interactions, the sharing of all the resources they are exploiting, the inscription of memory, they are sharing, but they are on top of their history, intentionally marking their history, and they are separating us from them. These are the three main pillars over which communities or the social identities built anthropologically, you know? So, I think what we have here is this agglomeration means actually this building of a community, of a social identity and a community. Tensories later, we will first see the appearances of social differences within this community. This will appear later. And, that is another story of course, and even later afterwards, we will see the disappearance of this system. That is yet another story. Thank you and sorry I took much time.