The chronology of the human colonization of the Canary Islands.

The human colonization of the Canary Islands represents the sole known expansion of Berber communities into the Atlantic Ocean and is an example of marine dispersal carried out by an African population. While this island colonization shows similarities to the populating of other islands across the world, several questions still need to be answered before this case can be included in wider debates regarding patterns of initial colonization and human settlement, human-environment interactions, and the emergence of island identities. Specifically, the chronology of the first human settlement of the Canary Islands remains disputed due to differing estimates of the timing of its first colonization. This absence of a consensus has resulted in divergent hypotheses regarding the motivations that led early settlers to migrate to the islands, e.g., ecological or demographic. Distinct motivations would imply differences in the strategies and dynamics of colonization; thus, identifying them is crucial to understanding how these populations developed in such environments. In response, the current study assembles a comprehensive dataset of the most reliable radiocarbon dates, which were used for building Bayesian models of colonization. The findings suggest that i) the Romans most likely discovered the islands around the 1st century BCE; ii) Berber groups from western North Africa first set foot on one of the islands closest to the African mainland sometime between the 1st and 3rd centuries CE; iii) Roman and Berber societies did not live simultaneously in the Canary Islands; and iv) the Berber people rapidly spread throughout the archipelago.

Osteosclerotic disease and bone cyst in a prehispanic burial from Las Cañadas del Teide (Tenerife, Canary Islands).

Skeletal remains of two prehispanic male adult individuals (antiquity ≈ 550 BP) recovered from a burial cave located in Montaña Blanca (Las Cañadas del Teide) at an altitude of 2450 m above sea level, in the highlands of Tenerife (Canary Islands) showed some unusual features. Femora and tibiae of both individuals showed increased bone density, with irregular thickening of the midshaft diaphyses. One individual showed a cystic lesion in the distal third of the left femoral diaphysis, surrounded by a subtle sclerotic reaction of the spongiosa and a thin cortex that was partially fractured. Periosteal thickening was present, but not around the cystic lesion. A thoracic vertebra with rachischisis was also recovered. The bone density of vertebrae and iliac bones were normal, and one recovered jaw was also normal. The tibiae of one individual showed an abnormal location of the foramen nutritium. Hypoplasia of the lesser trochanter and an abnormally thin left femoral neck were also observed. It is possible that both individuals were affected by diaphyseal dysplasia (possibly Camurati Engelmann or Ribbing disease). One of them also showed a lesion compatible with a unicameral bone cyst. The alternative possibility of a Klippel-Trenaunay-Weber disease, with a bone aneurysmal cyst, also exists.

The genomic history of the indigenous people of the Canary Islands.

The indigenous population of the Canary Islands, which colonized the archipelago around the 3rd century CE, provides both a window into the past of North Africa and a unique model to explore the effects of insularity. We generate genome-wide data from 40 individuals from the seven islands, dated between the 3rd-16rd centuries CE. Along with components already present in Moroccan Neolithic populations, the Canarian natives show signatures related to Bronze Age expansions in Eurasia and trans-Saharan migrations. The lack of gene flow between islands and constant or decreasing effective population sizes suggest that populations were isolated. While some island populations maintained relatively high genetic diversity, with the only detected bottleneck coinciding with the colonization time, other islands with fewer natural resources show the effects of insularity and isolation. Finally, consistent genetic differentiation between eastern and western islands points to a more complex colonization process than previously thought.

A Prehispanic infant from Tenerife with diffuse microporotic lesions.

We describe diffuse microporotic lesions observed in most of the scattered skeletal remains belonging to a ≈ 6 months-old female (genetic sexing) prehispanic (antiquity ≈ 600 years BP) individual recovered from a small recess of a basaltic burial cave in the highlands (2300 m above sea level) of Tenerife. Although sphenoid wings were lacking, microporotic lesions were present in several bones, especially in the hard palate, basilar part of the occipital bone, outer aspect of the maxilla, and proximal half of the right humerus, accompanied by a subtle periosteal reaction. Although non-specific, bone lesions may be compatible with scurvy, possibly in the context of malnutrition, that probably also affected the mother, given the young age of the infant and her dependence on maternal feeding. Pathophysiological connections among iron deficiency, vitamin C deficiency and vitamin D deficiency are discussed. Both observational reports on paleopathological cases of diffuse microporotic lesions as well as experimental studies devoted to discern the relative and combined effects of hypoxia-mediated bone marrow expansion, protein-calorie malnutrition, ascorbate, vitamin D or iron deficiency on such lesions are needed.

Paleogenomics of the prehistory of Europe: human migrations, domestication and disease.

A substantial portion of ancient DNA research has been centred on understanding European populations' origin and evolution. A rchaeological evidence has already shown that the peopling of Europe involved an intricate pattern of demic and/or cultural diffusion since the Upper Palaeolithic, which became more evident during the Neolithic and Bronze Age periods. However, ancient DNA data has been crucial in determining if cultural changes occurred due to the movement of ideas or people. With the advent of next-generation sequencing and population-based paleogenomic research, ancient DNA studies have been directed not only at the study of continental human migrations, but also to the detailed analysis of particular archaeological sites, the processes of domestication, or the spread of disease during prehistoric times. With this vast paleogenomic effort added to a proper archaeological contextualisation of results, a deeper understanding of Europe's peopling is starting to emanate.

The demography of the Canary Islands from a genetic perspective.

The establishment of European colonies across the world had important demographic consequences because it brought together diverse and distant civilizations for the first time. One clear example of this phenomenon is observed in the Canary Islands. The modern Canarian population is mainly the result of the admixture of natives of North African origin and European colonizers. However, additional migratory flows reached the islands due to the importation of enslaved Africans to cultivate sugarcane and the intense commercial contact with the American continent. In this review, we evaluate how the genetic analysis of indigenous, historical and current populations has provided a glimpse into the Canary Islands' complex genetic composition. We show that each island subpopulation's characterization is needed to fully disentangle the demographic history of the Canarian archipelago. Finally, we discuss what research avenues remain to be explored to improve our knowledge of the impact that the European colonization had on its native population.

Mitogenomes illuminate the origin and migration patterns of the indigenous people of the Canary Islands.

The Canary Islands' indigenous people have been the subject of substantial archaeological, anthropological, linguistic and genetic research pointing to a most probable North African Berber source. However, neither agreement about the exact point of origin nor a model for the indigenous colonization of the islands has been established. To shed light on these questions, we analyzed 48 ancient mitogenomes from 25 archaeological sites from the seven main islands. Most lineages observed in the ancient samples have a Mediterranean distribution, and belong to lineages associated with the Neolithic expansion in the Near East and Europe (T2c, J2a, X3a…). This phylogeographic analysis of Canarian ancient mitogenomes, the first of its kind, shows that some lineages are restricted to Central North Africa (H1cf, J2a2d and T2c1d3), while others have a wider distribution, including both West and Central North Africa, and, in some cases, Europe and the Near East (U6a1a1, U6a7a1, U6b, X3a, U6c1). In addition, we identify four new Canarian-specific lineages (H1e1a9, H4a1e, J2a2d1a and L3b1a12) whose coalescence dates correlate with the estimated time for the colonization of the islands (1st millennia CE). Additionally, we observe an asymmetrical distribution of mtDNA haplogroups in the ancient population, with certain haplogroups appearing more frequently in the islands closer to the continent. This reinforces results based on modern mtDNA and Y-chromosome data, and archaeological evidence suggesting the existence of two distinct migrations. Comparisons between insular populations show that some populations had high genetic diversity, while others were probably affected by genetic drift and/or bottlenecks. In spite of observing interinsular differences in the survival of indigenous lineages, modern populations, with the sole exception of La Gomera, are homogenous across the islands, supporting the theory of extensive human mobility after the European conquest.

Sexual dimorphism: a comparative study between the prehispanic inhabitants from El Hierro and other populations of the world

Sex estimation based on tibial measurements can be achieved using discriminant functions combining several parameters. However, functions differ from one population to another, because sexual dimorphism may be more or less marked among different ancestry or ethnic groups. Calculation of one of these functions with the dimensions of populations other than that from which the function was obtained may misclassify a different proportion of males or females than when calculated with the dimensions of the original population. By dividing the proportions of correctly classified individuals when the function was applied to the population from which it derived and that of El Hierro (Canary Islands), we can calculate an index of male trait expression and an index of female trait expression, and, by addition of both indices, an index of sexual dimorphism. Therefore, it is possible to compare the degree of sexual dimorphism among several populations, at least regarding those measurements included in the function. Based on this fact we have calculated several functions (reported in the scientific literature), obtained from tibiae of modern black, white, and Japanese populations, and from medieval Croatians and prehispanic inhabitants of Gran Canaria (ap. 1000 BP), with the dimensions of the prehispanic population of El Hierro, genetically sexed, also with an antiquity of ap. 1000 BP. Despite the different antiquity, the population of El Hierro was more dimorphic that the modern Japanese one, but less dimorphic than most of the other groups with which it was compared, especially when functions including distal epiphyseal breadth and minimum shaft perimeter (near the distal end of the tibiae) were calculated: in these cases, dimorphism was lower for the population of El Hierro, due to the fact that, although male trait expression index was higher, many females of El Hierro were misclassified as males because of the abnormally thick distal diaphyseal and epiphyseal breadths of El Hierro inhabitants

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A case of calcaneal osteomyelitis from the prehispanic population of El Hierro (Canary Islands).

A right calcaneus with a deep resorptive lesion surrounded by an osteosclerotic reaction in its lateral aspect was found among intermingled bone remains in a collective burial cave of the island of El Hierro, in the Canary Archipelago. It belonged to an adult prehispanic man, with an estimated antiquity of ≈1000 years BP. The bone shows a penetrating lesion in the lateral aspect slightly superior-anterior to the calcaneal tuberosity, surrounded by a bone rim, and communicating with a large cavity opening cranially where Achilles tendon is inserted. The lesion is suggestive of calcaneal osteomyelitis. The initiating cause was probably a puncture wound, perhaps with a retained foreign body that caused the large abscess. Other infectious and non-infectious etiologic possibilities are discussed.

A skeletal case of hypertrophic osteoarthropathy from the Canary Islands dating from 1000 BP.

A left tibia, the distal right tibia, and the proximal four fifths of the right ulna and radius, probably belonging to an adult prehispanic man (antiquity of ≈1000 years BP) were found among commingled bone remains in a collective burial cave of the island of El Hierro, in the Canary Archipelago. All four bones show an intense periosteal bone formation, encrusting the preserved cortical bone of the diaphyses. Differential diagnosis include melorheostosis, syphilis, and leprosy, although the most likely diagnosis is hypertrophic osteoarthropathy, which is usually associated with lung neoplasm or non-malignant diseases leading to chronic hypoxemia. The marked bone proliferation, possibly due to a chronic condition, suggests that possibly the underlying illness was a non-malignant one.

Relationships between bending and torsional strengths of the tibia and simple anthropometric variables among the prehispanic population of El Hierro (Canary Islands)

Assessment of skeletal robusticity is an important tool for the archaeologist and anthropologist, since it may be related to the intensity and type of activity performed by ancient population groups. Development of computed tomography (CT) allows determination of biomechanical properties of long bones. However, CT technology may not be easily available and is a relatively expensive procedure. Therefore, it is pertinent to estimate whether any of the parameters which can be easily measured in bare bones by simple anthropometry are useful to assess the torsional strength and bending strength of these bones. We included twenty one well preserved tibiae corresponding to prehispanic adult individuals (13 men) of El Hierro. These bones were anthropometrically measured following classical methods, and also subjected to CT analysis, and further calculation of minimum and maximum second moments and polar second moment of area, both at midshaft and at the nutrient foramen levels, using the software (www.hopkinsmedicine.org/FAE/mmacro.htm). The diaphyseal robusticity index showed a close relationship with minimum second moment of area at the nutrient foramen (r=0.824, p<0.001) and polar second moment of area at the nutrient foramen (r=0.824, p<0.001), whereas correlations with the epiphyseal robusticity index were weaker (r=0.628, p=0.005, and r=0.618, p=0.007, respectively). The variable which allows the best estimation of the torsional strength is the perimeter at the nutrient foramen, by the formula Polar second moment of area (in mm3) = -700.30 + 11.77 * perimeter at the nutrient foramen (in mm) for the whole population (standard error of the estimation=56.91; absolute range from-114.26 to 140.29), or Polar second moment of area (in mm3) = -897.93 + 13.74 * perimeter at the nutrient foramen (in mm) when only men were analyzed, with a standard error of the estimation of 32.17 (absolute range= from -44.53 to 50.32 mm3)

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Tibial marks in bare tibiae: relationship with robusticity indices

In bare bones, transverse lines may have several origins. Defleshing of a prey generates cutmarks, which can also appear in relation with traumatic events, post-mortem changes such as marks of animal teeth, rodent gnawing, or impact of stones, or even bone decoration. We hypothesize that in some instances they may be due to hyperplastic vessels beating on the bone surface, as expression of increased blood flow demand imposed by hypertrophied muscles. We analyzed 140 well-preserved tibiae which belonged to pre-Hispanic individuals from El Hierro, in the Canary Archipelago, currently kept at the Department of Archaeology and Prehistory of the University of La Laguna, and determined robusticity indices. Tibial marks were found in 53 out of 140 cases. Epiphyseal and diaphyseal robusticity indices were significantly higher in the first case among those with marks than among those without marks (T=3.13; p=0.002), and nearly significantly in the latter case (T=1.88; p=0.063). Considering only men, similar differences were observed regarding epiphyseal robusticity index (T=2.90; p=0.005) and diaphyseal robusticity index (T=2.11; p=0.039). There were also differences regarding the depth of the tibial marks: a higher epiphyseal robusticity index was associated with a more marked depth of the lines (T=2.11; p=0.042). An association was also observed between depth of the marks and sex (?2=4.12; p=0.042), more profound marks being observed among men. In conclusion, we here describe subtle bone marks in tibiae, which seem to correspond to vascular imprinting and are related to bone robustness. Whether or not they really represent an adaptation to an increased blood flow demand by hypertrophied muscles in relation with increased weight-bearing activity remains speculative, but this hypothesis may explain their presence (AU)

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