Changes in skull components of the squirrel monkey evoked by growth and nutrition: an experimental study

Twenty weanling 6-month-old male squirrel monkeys were allotted to the following treatments: 1) first control animals were killed at weaning; 2) second control animals were killed when 24 months old; and 3) malnourished animals were fed on a low-protein diet and killed at age 24 months. Lateral and vertical teleradiographies were taken. Growth of the neurocranial and splanchnocranial components were measured by volumetric (size estimators) and morphometric (shape estimators) indices. All facial components grew. The neurocranial components showed a heterogeneous behavior: The anteroneural component remained stable, and the increase of the midneural component was compensated by a decrease in the posteroneural component. Malnutrition affected the growths of 1) the craniofacial complex, 2) the splanchnocranium, and 3) the respiratory and midneural components. Growth influenced skull shape through 1) increases of the splanchnocranium and the midneural component relative to the neurocranium; 2) decreases of the masticatory and optic components relative to the splanchnocranium, and 3) decreases of the anteroneural and posteroneural components relative to the neurocranium. Malnutrition influenced skull shape through the relationship between the anteroneural component and the neurocranium. These results confirmed the existence of functional interrelationships among the cranial components. A new approach to craniological studies is suggested.     

Sexual dimorphism and cultural evolution in the Late Pleistocene and Holocene of Europe

Dental, cranial and body size data are reviewed for European Upper Paleolithic, Mesolithic and Neolithic males and females. Over these three periods there is a substantial decrease in the level of sexual dimorphism. From separate analysis of trends occurring between males and females, it is shown that the major cause for this decrease in sexual dimorphism is gracilization of the males between the Upper Paleolithic and Mesolithic. Reduction in males is related to shifting technological patterns associated with hunting and changes in the types of animals hunted. Further reduction in sexual dimorphism between the Mesolithic and Neolithic and from the Neolithic to modern European populations is shown to be more closely tied to changes occurring among females. Analysis of changing patterns of sexual dimorphism in Late Pleistocene and Holocene populations of Europe suggests an interrelationship between cultural and biological evolution.     

Microevolution of outer and inner structures of upper molars in Late Pleistocene and Early Holocene humans

In this study, we investigate outer and inner variations of upper second molars (UM2) for Late Pleistocene and Early Holocene modern humans, at a key-period in our evolutionary history associated with major sociocultural, economic and environmental changes. Non-metric traits have been recorded on 89 UM2 of 66 Upper Paleolithic, Mesolithic and Neolithic individuals, and 40 UM2 have been microscanned to assess variations in enamel thickness (ET) distribution and enamel–dentine junction (EDJ) shape. Major changes are found between Mesolithic and Neolithic periods: a decrease of the metacone expression combined with an increase of the hypocone development; an increase of the heterogeneity of ET distribution between lingual and buccal cusps; and an increase of the development of the dentine horn tips corresponding to the hypocone and, to a lesser extent, to the metacone. These morphological modifications could be linked to the masticatory functional changes associated with the transition to agriculture.     

Molecular phylogeography of domesticated barley traces expansion of agriculture in the Old World

Barley (Hordeum vulgare ssp. vulgare) was first cultivated 10,500 years ago in the Fertile Crescent and is one of the founder crops of Eurasian agriculture. Phylogeographic analysis of five nuclear loci and morphological assessment of two traits in >250 domesticated barley accessions reveal that landraces found in South and East Asia are genetically distinct from those in Europe and North Africa. A Bayesian population structure assessment method indicates that barley accessions are subdivided into six clusters and that barley landraces from 10 different geographical regions of Eurasia and North Africa show distinct patterns of distribution across these clusters. Using haplotype frequency data, it appears that the Europe/North Africa landraces are most similar to the Near East population (F ST = 0.15) as well as to wild barley (F ST = 0.11) and are strongly differentiated from all other Asian populations (F ST = 0.34-0.74). A neighbor-joining analysis using these F ST estimates also supports a division between European, North African, and Near East barley types from more easterly Asian accessions. There is also differentiation in the presence of a naked caryopsis and spikelet row number between eastern and western barley accessions. The data support the differential migration of barley from two domestication events that led to the origin of barley--one in the Fertile Crescent and another farther east, possibly at the eastern edge of the Iranian Plateau--with European and North African barley largely originating from the former and much of Asian barley arising from the latter. This suggests that cultural diffusion or independent innovation is responsible for the expansion of agriculture to areas of South and East Asia during the Neolithic revolution.     

Between the Baltic and Danubian Worlds: The Genetic Affinities of a Middle Neolithic Population from Central Poland

For a long time, anthropological and genetic research on the Neolithic revolution in Europe was mainly concentrated on the mechanism of agricultural dispersal over different parts of the continent. Recently, attention has shifted towards population processes that occurred after the arrival of the first farmers, transforming the genetically very distinctive early Neolithic Linear Pottery Culture (LBK) and Mesolithic forager populations into present-day Central Europeans. The latest studies indicate that significant changes in this respect took place within the post-Linear Pottery cultures of the Early and Middle Neolithic which were a bridge between the allochthonous LBK and the first indigenous Neolithic culture of north-central Europe—the Funnel Beaker culture (TRB). The paper presents data on mtDNA haplotypes of a Middle Neolithic population dated to 4700/4600–4100/4000 BC belonging to the Brześć Kujawski Group of the Lengyel culture (BKG) from the Kuyavia region in north-central Poland. BKG communities constituted the border of the “Danubian World” in this part of Europe for approx. seven centuries, neighboring foragers of the North European Plain and the southern Baltic basin. MtDNA haplogroups were determined in 11 individuals, and four mtDNA macrohaplogroups were found (H, U5, T, and HV0). The overall haplogroup pattern did not deviate from other post-Linear Pottery populations from central Europe, although a complete lack of N1a and the presence of U5a are noteworthy. Of greatest importance is the observed link between the BKG and the TRB horizon, confirmed by an independent analysis of the craniometric variation of Mesolithic and Neolithic populations inhabiting central Europe. Estimated phylogenetic pattern suggests significant contribution of the post-Linear BKG communities to the origin of the subsequent Middle Neolithic cultures, such as the TRB.     

Late Quaternary human settlement patterning in the Jebel Gharbi

This paper presents the latest results of geoarchaeological research on the Upper Pleistocene sequence in the Jebel Gharbi (previously called Jebel Nafusah), a mountain range located in Tripolitania, northwestern Libya. Numerous archaeological sites are found adjacent to springs that formed as a consequence of tectonic activities. The springs originated when Upper Pleistocene earthquakes produced ground displacements that created water outlets, some of which are still active. Springs are spread all along the massif and at the foot of the mountains in Jebel Gharbi. We suggest that they offered attractive resources to populations coming from drier parts of North Africa or the near-by Sahara. The earliest sites associated with the springs include Aterian lithic techno-complexes that have been dated between 80,000 and 40,000 BP. Since then, these springs have attracted many populations, as documented here by settlements belonging to the Later Stone Age (Upper Palaeolithic), Iberomaurusian (Late Upper Palaeolithic or Epipalaeolithic), Neolithic, Roman period, and present time.     

Late archaic and modern Homo sapiens from Europe, Africa, and Southwest Asia: Craniometric comparisons and phylogenetic implications

The craniometric affinities among Neandertals. Upper Palcolithic Europeans, early anatomically modern Southwest Asians, and archaic and modern Africans are investigated using univariate and multivariate methods. For the first time, it is possible to analyse the North African finds Dar-es-Soltane 5, Nazlet Khater, and Wadi Kubbaniya. It was not possible to include the Neandertals from Central Europe due to their poor state of preservation. The results point to, first, a basic distinction between Neandertals on the one hand and modern humans from all geographic regions on the other, and, secondly, to great similarities between modern African and European populations. Late archaic sapiens specimens from Africa were more similar to Upper Paleolithic Europeans than were the Neandertals. The results do not support the hypothesis that a regional evolution giving rise to modern humans took place in Europe. The results are, however, consistent with the hypothesis that modern populations originated in Africa and spread to Europe from there.     

The origin and dispersion of human parasitic diseases in the old world (Africa,Europe and Madagascar)

The ancestors of present-day man (Homo sapiens sapiens) appeared in East Africa some three and a half million years ago (Australopithecs), and then migrated to Europe, Asia, and later to the Americas, thus beginning the differentiation process. The passage from nomadic to sedentary life took place in the Middle East in around 8000 BC. Wars, spontaneous migrations and forced migrations (slave trade) led to enormous mixtures of populations in Europe and Africa and favoured the spread of numerous parasitic diseases with specific strains according to geographic area. The three human plasmodia (Plasmodium falciparum, P. vivax, and P. malariae) were imported from Africa into the Mediterranean region with the first human migrations, but it was the Neolithic revolution (sedentarisation, irrigation, population increase) which brought about actual foci for malaria. The reservoir for Leishmania infantum and L. donovani--the dog--has been domesticated for thousands of years. Wild rodents as reservoirs of L. major have also long been in contact with man and probably were imported from tropical Africa across the Sahara. L. tropica, by contrast, followed the migrations of man, its only reservoir. L. infantum and L. donovani spread with man and his dogs from West Africa. Likewise, for thousands of years, the dog has played an important role in the spread and the endemic character of hydatidosis through sheep (in Europe and North Africa) and dromadary (in the Sahara and North Africa). Schistosoma haematobium and S. mansoni have existed since prehistoric times in populations living in or passing through the Sahara. These populations then transported them to countries of Northern Africa where the specific, intermediary hosts were already present. Madagascar was inhabited by populations of Indonesian origin who imported lymphatic filariosis across the Indian Ocean (possibly of African origin since the Indonesian sailors had spent time on the African coast before reaching Madagascar). Migrants coming from Africa and Arabia brought with them the two African forms of bilharziosis: S. haematobium and S. mansoni.     

Genomic ancestry of North Africans supports back-to-Africa migrations

North African populations are distinct from sub-Saharan Africans based on cultural, linguistic, and phenotypic attributes; however, the time and the extent of genetic divergence between populations north and south of the Sahara remain poorly understood. Here, we interrogate the multilayered history of North Africa by characterizing the effect of hypothesized migrations from the Near East, Europe, and sub-Saharan Africa on current genetic diversity. We present dense, genome-wide SNP genotyping array data (730,000 sites) from seven North African populations, spanning from Egypt to Morocco, and one Spanish population. We identify a gradient of likely autochthonous Maghrebi ancestry that increases from east to west across northern Africa; this ancestry is likely derived from "back-to-Africa" gene flow more than 12,000 years ago (ya), prior to the Holocene. The indigenous North African ancestry is more frequent in populations with historical Berber ethnicity. In most North African populations we also see substantial shared ancestry with the Near East, and to a lesser extent sub-Saharan Africa and Europe. To estimate the time of migration from sub-Saharan populations into North Africa, we implement a maximum likelihood dating method based on the distribution of migrant tracts. In order to first identify migrant tracts, we assign local ancestry to haplotypes using a novel, principal component-based analysis of three ancestral populations. We estimate that a migration of western African origin into Morocco began about 40 generations ago (approximately 1,200 ya); a migration of individuals with Nilotic ancestry into Egypt occurred about 25 generations ago (approximately 750 ya). Our genomic data reveal an extraordinarily complex history of migrations, involving at least five ancestral populations, into North Africa.     

Dental morphology of the Dawenkou Neolithic population in North China: implications for the origin and distribution of Sinodonty

We compare the incidence of 25 nonmetric dental traits of the people of the Neolithic Dawenkou culture (6300-4500 BP) sites in Shandong Province, North China with those of other East Asian populations. The Dawenkou teeth had an overwhelmingly greater resemblance to the Sinodont pattern typical of Northeast Asia than to the Sundadont pattern typical of Southeast Asia. Multidimensional scaling using Smith's mean measure of divergence (MMD) statistic place the Dawenkou sample near the Amur and the North China-Mongolia populations in the area of the plot indicating typical Sinodonty. The existence of the Sinodont population in Neolithic North China suggests a possible continuity of Sinodonty from the Upper Cave population at Zhoukoudian (about 34000-10000 BP) to the modern North Chinese. The presence of Sinodonty in Shandong Province shows that the Japan Sea and East China Sea were strong barriers to gene flow for at least 3000 years, because at this time the Jomonese of Japan were fully Sundadont. In addition, we suggest that the descendants of the Dawenkou population cannot be excluded as one of the source populations that contributed to sinodontification in Japan.     

Amphisbaenian paleobiogeography: Evidence of vicariance and geodispersal patterns

Paleobiogeographic patterns within the Amphisbaenia were evaluated using the modified Brooks Parsimony Analysis (BPA) and recently published morphological and molecular phylogenies. Extant amphisbaenians are present in Africa, South America, North America, Europe, and the Middle East. The modified BPA was used to determine the relative effects of Pangean breakup, sea-level change, and climate change on evolutionary and distributional patterns within the Amphisbaenia. The modified BPA also tested the biogeographic effect of the Rhineuridae's phylogenetic position as either most basal in the morphologic phylogeny or most derived in the molecular phylogeny. The morphological and molecular analyses resulted in two different biogeographic hypotheses. The morphological analysis indicated three major biogeographic regions for the Amphisbaenia: 1) Africa, South America, and the Caribbean, 2) western Asia, and 3) North America. The molecular analysis indicated two major biogeographic regions: 1) Africa, western Asia, and North America, and 2) South America. The morphological biogeographic pattern corresponds with the known timing of the breakup of Pangea and the resulting paleogeographic reconstructions of the Mesozoic and Early Cenozoic. While the molecular pattern is similar to patterns recovered from dinosaurian biogeographic studies, the closer connection of Africa with North America rather than South America does not match well-constrained geologic evidence for the sequence of Pangean breakup. Both paleobiogeographic analyses, however, resulted in congruent patterns of speciation through vicariance and geodispersal. This suggests that in addition to the breakup of Pangea, such cyclical Earth history processes as sea-level and climate changes played an important role in the biogeographic patterns of the Amphisbaenia.     

Iberia: population genetics, anthropology, and linguistics.

Basques, Portuguese, Spaniards, and Algerians have been studied for HLA and mitochondrial DNA markers, and the data analysis suggests that pre-Neolithic gene flow into Iberia came from ancient white North Africans (Hamites). The Basque language has also been used to translate the Iberian-Tartesian language and also Etruscan and Minoan Linear A. Physical anthropometry of Iberian Mesolithic and Neolithic skeletons does not support the demic replacement in Iberia of preexisting Mesolithic people by Neolithic people bearing new farming technologies from Europe and the Middle East. Also, the presence of cardial impressed pottery in western Mediterranean Europe and across the Maghreb (North Africa) coasts at the beginning of the Neolithic provides good evidence of pre-Neolithic circum-Mediterranean contacts by sea. In addition, pre-dynastic Egyptian El-Badari culture (4,500 years ago) is similar to southern Iberian Neolithic settlements with regard to pottery and animal domestication. Taking the genetic, linguistic, anthropological, and archeological evidence together with the documented Saharan area desiccation starting about 10,000 years ago, we believe that it is possible that a genetic and cultural pre-Neolithic flow coming from southern Mediterranean coasts existed toward northern Mediterranean areas, including at least Iberia and some Mediterranean islands. This model would substitute for the demic diffusion model put forward to explain Neolithic innovations in Western Europe.     

Factors regulating the invasive success of an alien frog: a comparison of the ecology of the native and alien populations

We examined niche occupancy of Discoglossus pictus, an anuran recently established in Europe, comparing the niches of native (North Africa) and alien populations (south-western Europe) at two spatial scales to determine whether adaptive divergence had occurred between these two populations. Additionally, we determine whether the alien species showed a wider larvae niche and higher phenotypic variability compared with co-occurring anurans. We characterized the breeding habitats and the climatic space occupied by native and alien groups of populations of D. pictus and examined morphological traits of D. pictus and sympatric anuran larvae. Our results revealed no divergence in breeding habitat use between native and alien populations. A shift was observed between the realized niches occupied by the native and alien populations, but this shift might only reflect cryptic niche conservatism. The range of reproductive habitats selected by D. pictus was not wider than those of most native species. In the invaded range, D. pictus showed morphological overlap with some native species and broader phenotypic variability, but the adaptive advantages of this latter attribute were uncertain. Our results suggest that the invasive capacity of this species depends on favourable abiotic conditions rather than on its adaptive advantages over native anurans.     

Step-wise morphological trends in fluctuating environments: Evidence in the Late Devonian conodont genus Palmatolepis

Long-term morphological changes were investigated in the conodont genus Palmatolepis, using a Fourier analysis of the outline of platform elements. Three time-slices and four Late Frasnian - Early Famennian sections on North Gondwana were studied. No difference existed between locations, but shape variations were recorded associated with the successive Kellwasser events. The Middle Famennian period was analyzed in a section located at the Baltica margin across the annulata event. Some morphological changes may be related to the deposition of the corresponding black shales, but the main feature is a heterogeneity of the populations, which can be split into two morphological types. Latest Famennian conodonts from another North Gondwanan section show only minor shape changes during this time interval, which is environmentally stable prior to the global Hangenberg event. Based on synthetic shape variations across the whole period an morphological trend towards narrower elements is observed. This morphological change happens step-wise in response to global events. The amplitude of the shape shift is proportionally related to the extend of the successive Late Devonian global events.     

Craniofacial morphology in the Argentine Center-West: consequences of the transition to food production

The Argentine Center-West was the southernmost portion of the Andes where domestication of plants and animals evolved. Populations located in the southern portion of this area displayed a hunter-gatherer subsistence economy up to historical times, and coexisted with farmers located to the north. Archaeological and biological evidence suggests that the transition to food production was associated with the consumption of a softer diet and a more sedentary way of life. This study tests the hypothesis that diet-related factors influenced morphological differentiation, by comparing functional cranial components of farmers and hunter-gatherers. Three-dimensional changes on eight minor functional components (anteroneural, midneural, posteroneural, otic, optic, respiratory, masticatory, and alveolar) were measured on skulls derived from both subareas. Volumetric and morphometric indices were calculated to estimate the absolute and relative size of components, respectively. Results of a paired t-test indicated that farmers have a smaller craniofacial size than hunter-gatherers. The components that varied the most were masticatory and posteroneural, showing smaller absolute and relative sizes in farmers. Discriminant analyses indicated that lengths and widths were the most affected dimensions of these and other components. The pattern of differentiation, which involves specific components, enabled us to exclude differential gene flow and stochastic mechanisms as the main causes. Instead, results support the hypothesis that diet-related factors associated with both subsistence economies influenced craniofacial morphology. A proportion of the observed variation associated with size differences can be explained by two systemic factors: the lesser quality of nutrition due to a low protein content in the diet, and a decrease of growth hormone circulation induced by a lower mobility due to sedentism. However, differentiation is better explained by a localized factor: the reduction in the masticatory and posteroneural components in farmers resulted from a decrease of masticatory stresses and workload on the head and neck, linked to the consumption of a softer diet.     

福建漳平奇和洞发现的新石器时代早期人类头骨

2011年在福建漳平奇和洞发现的距今1万年左右的新石器时代早期人类遗骸"奇和洞III号",是迄今在福建地区发现的最早、最完整的古人类头骨,为探讨华南更新世晚期向全新世过渡阶段人类的体质特征及现代人群的形成与分化提供了重要的研究材料。本文对这件头骨进行了研究,奇和洞III号为35岁左右的男性个体,牙齿龋病严重,推测当时人类的经济模式主要以农耕为主。通过与更新世晚期柳江、山顶洞101号及14组新石器时代人类头骨的比较,发现奇和洞III号头骨兼有更新世晚期人类及新石器南、北方居民的混合体质特征:奇和洞III号头骨长而脑量大,似更新世晚期人类;其高而狭窄的面部、宽阔而低矮的鼻部,呈现出不同于南、北方人群的特殊体质特征。主成分分析显示,奇和洞III号与对比的新石器时代各组在头骨的测量数据上没有表现为明显的南、北地区间差异,但在头骨的测量指数或形状上存在时代和地区间的不同。本文研究为新旧石器过渡阶段人类体质特征的变异提供了进一步证据。     

Origins and spread of agriculture in Italy: a nonmetric dental analysis

Dental morphological traits were employed in this study as direct indicators of biological affinities among the populations that inhabited the Italian peninsula from the Upper Paleolithic-Mesolithic to Medieval times. Our analysis aims at contributing to the ongoing debate regarding the origin and spread of agriculture in the peninsula by contrasting the dental evidence of archaeological and modern molecular samples. It is not possible to generalize given the complex and dynamic nature of these populations. However, the results from the principal component analysis, maximum likelihood, mean measure of divergence, and multidimensional scaling do indicate a net separation of the Paleo-Mesolithic sample from the other groups that is not related to dental reduction. This suggests that the shift in dental morphology was the product of Neolithic populations migrating into the peninsula from other areas. Nonetheless, the Paleo-Mesolithic populations share several discriminative traits with the Neolithic group. The biological relevance of such evidence suggests that, to some minor extent, the spread of agriculture did not occur by total population replacement. Because of regional small sample sizes, this hypothesis cannot be tested on a micro-regional scale. It is, however, feasible to depict a scenario where processes of genetic mixture or replacement probably took place at different rates on a macro-regional level.     

Human Alu insertion polymorphisms in North African populations

Several features make Alu insertions a powerful tool used in population genetic studies: the polymorphic nature of many Alu insertions, the stability of an Alu insertion event and, furthermore, the ancestral state of an Alu insertion is known to be the absence of the Alu element at a particular locus and the presence of an Alu insertion at the site that forward mutational change. This study analyses seven Alu insertion polymorphisms in a sample of 297 individuals from the autochthonous population of Tunisia (Thala, Smar, Zarzis, and Bou Salem) and Libya with the aim of studying their genetic structure with respect to the populations of North Africa, Western, Eastern and Central Europe. The comparative analyses carried out using the MDS and AMOVA methods reveal the existence of spatial heterogeneity, and identify four population groups. Study populations (Libya, Smar, Zarzis, and Bou Salem) are closest to North African populations whereas Thala is isolated and is closest to Western European populations. In conclusion, Results of the present study support the important role that migratory movements have played in the North African gene pool, at least since the Neolithic period.     

Ancient DNA from South-East Europe Reveals Different Events during Early and Middle Neolithic Influencing the European Genetic Heritage

The importance of the process of Neolithization for the genetic make-up of European populations has been hotly debated, with shifting hypotheses from a demic diffusion (DD) to a cultural diffusion (CD) model. In this regard, ancient DNA data from the Balkan Peninsula, which is an important source of information to assess the process of Neolithization in Europe, is however missing. In the present study we show genetic information on ancient populations of the South-East of Europe. We assessed mtDNA from ten sites from the current territory of Romania, spanning a time-period from the Early Neolithic to the Late Bronze Age. mtDNA data from Early Neolithic farmers of the Starčevo Criş culture in Romania (Cârcea, Gura Baciului and Negrileşti sites), confirm their genetic relationship with those of the LBK culture (Linienbandkeramik Kultur) in Central Europe, and they show little genetic continuity with modern European populations. On the other hand, populations of the Middle-Late Neolithic (Boian, Zau and Gumelniţa cultures), supposedly a second wave of Neolithic migration from Anatolia, had a much stronger effect on the genetic heritage of the European populations. In contrast, we find a smaller contribution of Late Bronze Age migrations to the genetic composition of Europeans. Based on these findings, we propose that permeation of mtDNA lineages from a second wave of Middle-Late Neolithic migration from North-West Anatolia into the Balkan Peninsula and Central Europe represent an important contribution to the genetic shift between Early and Late Neolithic populations in Europe, and consequently to the genetic make-up of modern European populations.     

Mitochondrial DNA affinities at the Atlantic fringe of Europe

Mitochondrial DNA analysis of Atlantic European samples has detected significant latitudinal clines for several clusters with Paleolithic (H) and Neolithic (J, U4, U5a1, and U5a1a) coalescence ages in Europe. These gradients may be explained as the result of Neolithic influence on a rather homogeneous Paleolithic background. There is also evidence that some Neolithic clusters reached this border by a continental route (J, J1, J1a, U5a1, and U5a1a), whereas others (J2) did so through the Mediterranean coast. An important gene flow from Africa was detected in the Atlantic Iberia. Specific sub-Saharan lineages appeared mainly restricted to southern Portugal, and could be attributed to historic Black slave trade in the area and to a probable Saharan Neolithic influence. In fact, U6 haplotypes of specific North African origin have only been detected in the Iberian peninsula northwards from central Portugal. Based on this peculiar distribution and the high diversity pi value (0.014 +/- 0.001) in this area compared to North Africa (0.006 +/- 0.001), we reject the proposal that only historic events such as the Moslem occupation are the main cause of this gene flow, and instead propose a pre-Neolithic origin for it.