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1.
Sci Rep ; 8(1): 3170, 2018 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-29545620

RESUMO

Dinosaurs thrived and reproduced in various regions worldwide, including the Arctic. In order to understand their nesting in diverse or extreme environments, the relationships between nests, nesting environments, and incubation methods in extant archosaurs were investigated. Statistical analyses reveal that species of extant covered nesters (i.e., crocodylians and megapodes) preferentially select specific sediments/substrates as a function of their nesting style and incubation heat sources. Relationships between dinosaur eggs and the sediments in which they occur reveal that hadrosaurs and some sauropods (i.e., megaloolithid eggs) built organic-rich mound nests that relied on microbial decay for incubation, whereas other sauropods (i.e., faveoloolithid eggs) built sandy in-filled hole nests that relied on solar or potentially geothermal heat for incubation. Paleogeographic distribution of mound nests and sandy in-filled hole nests in dinosaurs reveals these nest types produced sufficient incubation heat to be successful up to mid latitudes (≤47°), 10° higher than covered nesters today. However, only mound nesting and likely brooding could have produced sufficient incubation heat for nesting above the polar circle (>66°). As a result, differences in nesting styles may have placed restrictions on the reproduction of dinosaurs and their dispersal at high latitudes.


Assuntos
Comportamento de Nidação , Animais , Regiões Árticas , Comportamento Animal , Dinossauros , Ecossistema , Meio Ambiente , Ambientes Extremos , Feminino , Fósseis , História Antiga , Óvulo/metabolismo , Paleografia , Reprodução
2.
Am J Phys Anthropol ; 165(3): 471-479, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29159821

RESUMO

OBJECTIVES: The objectives of this study were to develop a new subadult-adult ratio for application to sites with good infant representation and to produce an equation to estimate the total fertility rate for a population based on the age-at-death ratio. A new approach is required as current methods exclude the 0-4 years age category due to presumed underenumeration of infants. While this is true for some skeletal samples, others experience good infant representation. MATERIALS AND METHODS: Using age-at-death data and total fertility rates for 52 countries from the United Nations database for the year 1960, we examined the correlation between three age-at-death ratios and the fertility rate. We also utilized linear regression to determine an equation for calculating total fertility rate from the ratio. RESULTS: We achieved a correlation of 0.848 between our D0-14/D Ratio and actual fertility rates. This correlation was significantly higher (p < .05) than the other ratios examined, including the d5-14/d20+ by Bocquet-Appel and Masset () and the 15 P5 index by Bocquet-Appel (). DISCUSSION: The exclusion of infants can result in inaccurate demographic measures, particularly where subadults aged over 5 years of age experience robust survivorship. In addition to providing a solution for sites with good infant representation, this study indicates that the 0-4 years of age category possesses great predictive power when compared to other age categories. The regression equation provides a total fertility rate which is comparable with data regardless of their temporal origin. This method will provide more accurate demographic measures for bioarcheological sites with good infant preservation.


Assuntos
Coeficiente de Natalidade , Demografia/métodos , Fertilidade , Adolescente , Adulto , Antropologia Física , Criança , Feminino , Humanos , Modelos Lineares , Modelos Estatísticos , Paleografia , Adulto Jovem
3.
Gynecol Endocrinol ; 34(1): 25-27, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29073793

RESUMO

Mankind has been expressing the breeding topic for thousands of years. Reproduction is the primary instinct of human beings and it is a social, cultural, medical issue. Demographic infertility is one of them, which is defined infertility as the inability to become pregnant with a live birth, within five years of regular sexual contact based upon a consistent union status in marriage maintaining a desire for a child with the lack of contraceptive use and non-lactating. A first mentions about infertility and surrogacy is discovered on a 4000-year-old clay tablet of marriage contract belonging to the Assyrian period exhibited at Istanbul Archeology Museum in Turkey. In conclusion, there are many different ways to solve infertility problems like surrogacy as mentioned even 4000 years ago in this Assyrian clay tablet of marriage contract as the first time in the literature. Medical treatments in relation to human infertility will continue to be the focus of social and cultural debates. Hence, more legislation and regulation will come in many countries to control the unauthorized exploitation of the patient.


Assuntos
Infertilidade/história , Mães Substitutas , Arqueologia , Feminino , História Antiga , Humanos , Masculino , Casamento/história , Casamento/legislação & jurisprudência , Paleografia , Turquia , Redação
4.
Clin Microbiol Infect ; 22(11): 911-915, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27615720

RESUMO

Plague, a deadly zoonose caused by the bacterium Yersinia pestis, has been firmly documented in 39 historical burial sites in Eurasia that date from the Bronze Age to two historical pandemics spanning the 6th to 18th centuries. Palaeomicrobiologic data, including gene and spacer sequences, whole genome sequences and protein data, confirmed that two historical pandemics swept over Europe from probable Asian sources and possible two-way-ticket journeys back from Europe to Asia. These investigations made it possible to address questions regarding the potential sources and routes of transmission by completing the standard rodent and rodent-flea transmission scheme. This suggested that plague was transmissible by human ectoparasites such as lice, and that Y. pestis was able to persist for months in the soil, which is a source of reinfection for burrowing mammals. The analyses of seven complete genome sequences from the Bronze Age indicated that Y. pestis was probably not an ectoparasite-borne pathogen in these populations. Further analyses of 14 genomes indicated that the Justinian pandemic strains may have formed a clade distinct from the one responsible for the second pandemic, spanning in Y. pestis branch 1, which also comprises the third pandemic strains. Further palaeomicrobiologic studies must tightly connect with historical and anthropologic studies to resolve questions regarding the actual sources of plague in ancient populations, alternative routes of transmission and resistance traits. Answering these questions will broaden our understanding of plague epidemiology so we may better face the actuality of this deadly infection in countries where it remains epidemic.


Assuntos
DNA/análise , Peste/epidemiologia , Peste/história , Yersinia pestis/genética , Ásia/epidemiologia , DNA/história , Europa (Continente)/epidemiologia , Evolução Molecular , História do Século XV , História do Século XVI , História do Século XVII , História do Século XVIII , História Medieval , Humanos , Paleografia , Pandemias , Peste/microbiologia
5.
Sci Rep ; 6: 30590, 2016 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-27460966

RESUMO

The origin, affinity and paleoecology of macrofossils of soft-bodied organisms of the terminal Ediacaran Period have been highly debated. Previous discoveries in South America are restricted to small shelly metazoans of the Nama Assemblage. Here we report for the first time the occurrence of discoidal structures from the Upper Ediacaran Cerro Negro Formation, La Providencia Group, Argentina. Specimens are preserved in tabular sandstones with microbially-induced sedimentary structures. Flute marks and linear scours at the base of the sandstone layers indicate deposition under high energy, episodic flows. Stratigraphic, sedimentologic, petrographic and taphonomic analyses indicate that the origin of these structures is not related to abiotic process. Preservational and morphological features, as invagination and the presence of radial grooves, indicate that they resemble typical morphs of the Aspidella plexus. The large number of small-sized individuals and the wide range of size classes with skewed distribution suggest that they lived in high-density communities. The presence of Aspidella in the Cerro Negro Formation would represent the first reliable record of Ediacaran soft-bodied organisms in South America. It also supports the paleogeographic scenario of the Clymene Ocean, in which a shallow sea covered part of the southwest Gondwana at the end of the Ediacaran.


Assuntos
Fósseis , Evolução Biológica , Fósseis/anatomia & histologia , Sedimentos Geológicos , Paleografia , América do Sul
6.
FEMS Microbiol Ecol ; 92(7)2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27162179

RESUMO

The multiannual dynamic of the cyst-forming and toxic marine dinoflagellate Alexandrium minutum was studied over a time scale of about 150 years by a paleoecological approach based on ancient DNA (aDNA) quantification and cyst revivification data obtained from two dated sediment cores of the Bay of Brest (Brittany, France). The first genetic traces of the species presence in the study area dated back to 1873 ± 6. Specific aDNA could be quantified by a newly developed real-time PCR assay in the upper core layers, in which the germination of the species (in up to 17-19-year-old sediments) was also obtained. In both cores studied, our quantitative paleogenetic data showed a statistically significant increasing trend in the abundance of A. minutum ITS1 rDNA copies over time, corroborating three decades of local plankton data that have documented an increasing trend in the species cell abundance. By comparison, paleogenetic data of the dinoflagellate Scrippsiella donghaienis did not show a coherent trend between the cores studied, supporting the hypothesis of the existence of a species-specific dynamic of A. minutum in the study area. This work contributes to the development of paleoecological research, further showing its potential for biogeographical, ecological and evolutionary studies on marine microbes.


Assuntos
Dinoflagelados/isolamento & purificação , Sedimentos Geológicos/parasitologia , Baías , DNA Ribossômico/genética , Dinoflagelados/classificação , Dinoflagelados/genética , Dinoflagelados/metabolismo , Ecossistema , França , Sedimentos Geológicos/química , História do Século XX , História do Século XXI , Paleografia/história , Reação em Cadeia da Polimerase em Tempo Real , Especificidade da Espécie
7.
PLoS One ; 11(2): e0148341, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26849648

RESUMO

The Late Cretaceous echinoid genus Micraster (irregular echinoids, Spatangoida) is one of the most famous examples of a continuous evolutionary lineage in invertebrate palaeontology. The influence of the environment on the phenotype, however, was not tested so far. This study analyses differences in phenotypical variations within three populations of Micraster (Gibbaster) brevis from the early Coniacian, two from the Münsterland Cretaceous Basin (Germany) and one from the North Cantabrian Basin (Spain). The environments of the Spanish and the German sites differed by their sedimentary characteristics, which are generally a crucial factor for morphological adaptations in echinoids. Most of the major phenotypical variations (position of the ambitus, periproct and development of the subanal fasciole) among the populations can be linked to differences in their host sediments. These phenotypic variations are presumed to be an expression of phenotpic plasticiy, which has not been considered in Micraster in previous studies. Two populations (Erwitte area, Germany; Liencres area, Spain) were tested for stochastic variation (fluctuating asymmetry) due to developmental instability, which was present in all studied traits. However, differences in the amount of fluctuating asymmetry between both populations were recognised only in one trait (amount of pore pairs in the anterior paired petals). The results strengthen previous assumptions on ecophenotypic variations in Micraster.


Assuntos
Ecótipo , Ouriços-do-Mar/anatomia & histologia , Ouriços-do-Mar/fisiologia , Animais , Evolução Biológica , Fósseis , Alemanha , Paleografia , Fenótipo , Ouriços-do-Mar/crescimento & desenvolvimento , Espanha
8.
Zootaxa ; 3949(2): 281-8, 2015 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-25947807

RESUMO

Two new mayfly genera and species from the Triassic deposits of the Palegi area (southeast Poland) are described. This is the first description of aquatic insects from the Palegi locality. Triassolitophlebia palegica gen. et sp. nov. (Litophlebiidae) is established on the basis of an isolated forewing. This is the first finding of this family in the Northern Hemisphere, known previously only from the Molteno Formation (South Africa). This is also the first mayfly family from the Triassic which has been found in both Hemispheres, providing additional evidence of the presumed similarity of aquatic insect faunas in the Southern and Northern Hemispheres during the Triassic. The consistent wing venation of ancient mayflies with homonomous wings could be evidence that they originated from the same ancestor. The second new mayfly, Palegonympha triassica gen. et sp. nov. (Vogesonymphidae), is described on the basis of a single fossil nymph (imprint of the exuviae) and indicates the similarity of the Palegi arthropod assemblage to that described from the Middle Triassic of France. The presence of a mayfly nymph in the last instar stage suggests not only that the Palegi deposit represents a fluvial environment with well-oxygenated and limpid water but also that these conditions lasted long enough to allow for such development.


Assuntos
Evolução Biológica , Ephemeroptera/genética , Distribuição Animal , Animais , Ephemeroptera/anatomia & histologia , Ephemeroptera/classificação , Ephemeroptera/crescimento & desenvolvimento , Fósseis/anatomia & histologia , Tamanho do Órgão , Paleografia , Polônia , Asas de Animais/anatomia & histologia
9.
Am J Phys Anthropol ; 154(2): 222-31, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24523247

RESUMO

An agent-based model (ABM) is used to explore how the ratio of old to young adults (the OY ratio) in a sample of dead individuals is related to aspects of mortality, fertility, and longevity experienced by the living population from which the sample was drawn. The ABM features representations of rules, behaviors, and constraints that affect person- and household-level decisions about marriage, reproduction, and infant mortality in hunter-gatherer systems. The demographic characteristics of the larger model system emerge through human-level interactions playing out in the context of "global" parameters that can be adjusted to produce a range of mortality and fertility conditions. Model data show a relationship between the OY ratios of living populations (the living OY ratio) and assemblages of dead individuals drawn from those populations (the dead OY ratio) that is consistent with that from empirically known ethnographic hunter-gatherer cases. The dead OY ratio is clearly related to the mean ages, mean adult mortality rates, and mean total fertility rates experienced by living populations in the model. Sample size exerts a strong effect on the accuracy with which the calculated dead OY ratio reflects the actual dead OY ratio of the complete assemblage. These results demonstrate that the dead OY ratio is a potentially useful metric for paleodemographic analysis of changes in mortality and mean age, and suggest that, in general, hunter-gatherer populations with higher mortality, higher fertility, and lower mean ages are characterized by lower dead OY ratios.


Assuntos
Coeficiente de Natalidade/etnologia , Demografia/métodos , Mortalidade/etnologia , Paleografia , Dinâmica Populacional/estatística & dados numéricos , Adolescente , Adulto , Fatores Etários , Comportamento Alimentar , Feminino , Fósseis , Humanos , Masculino , Adulto Jovem
10.
PLoS One ; 8(9): e72931, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24039825

RESUMO

The Out-of-Africa model holds that anatomically modern humans (AMH) evolved and dispersed from Africa into Asia, and later Europe. Palaeoanthropological evidence from the Near East assumes great importance, but AMH remains from the region are extremely scarce. 'Egbert', a now-lost AMH fossil from the key site of Ksar Akil (Lebanon) and 'Ethelruda', a recently re-discovered fragmentary maxilla from the same site, are two rare examples where human fossils are directly linked with early Upper Palaeolithic archaeological assemblages. Here we radiocarbon date the contexts from which Egbert and Ethelruda were recovered, as well as the levels above and below the findspots. In the absence of well-preserved organic materials, we primarily used marine shell beads, often regarded as indicative of behavioural modernity. Bayesian modelling allows for the construction of a chronostratigraphic framework for Ksar Akil, which supports several conclusions. The model-generated age estimates place Egbert between 40.8-39.2 ka cal BP (68.2% prob.) and Ethelruda between 42.4-41.7 ka cal BP (68.2% prob.). This indicates that Egbert is of an age comparable to that of the oldest directly-dated European AMH (Pestera cu Oase). Ethelruda is older, but on current estimates not older than the modern human teeth from Cavallo in Italy. The dating of the so-called "transitional" or Initial Upper Palaeolithic layers of the site may indicate that the passage from the Middle to Upper Palaeolithic at Ksar Akil, and possibly in the wider northern Levant, occurred later than previously estimated, casting some doubts on the assumed singular role of the region as a locus for human dispersals into Europe. Finally, tentative interpretations of the fossil's taxonomy, combined with the chronometric dating of Ethelruda's context, provides evidence that the transitional/IUP industries of Europe and the Levant, or at least some of them, may be the result of early modern human migration(s).


Assuntos
Arqueologia , Evolução Biológica , Grupo com Ancestrais do Continente Europeu , Teorema de Bayes , Europa (Continente) , Fósseis , Geografia , Humanos , Líbano , Paleografia
12.
Naturwissenschaften ; 96(2): 289-95, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19052720

RESUMO

A giant termite is described and figured from the Late Miocene of the Styrian Basin in southeastern Austria. Gyatermes styriensis gen. n. et sp. n. is represented by a relatively complete forewing, with basal scale. The fossil approximates in size the largest of all termites today and is the largest fossil termite on record. The presence of this species in the Late Miocene fauna of Europe indicates that climatic conditions were appropriate for the persistence of species and colonies requiring relatively stable, warm conditions. The genus is primitive in overall features but shares some similarity with the dampwood termites.


Assuntos
Isópteros/anatomia & histologia , Animais , Áustria , Tamanho Corporal , Clima , História Antiga , Paleografia , Paleontologia , Asas de Animais/anatomia & histologia
13.
PLoS One ; 3(3): e0001744, 2008 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-18320025

RESUMO

Understanding feedbacks between terrestrial and atmospheric systems is vital for predicting the consequences of global change, particularly in the rapidly changing Arctic. Fire is a key process in this context, but the consequences of altered fire regimes in tundra ecosystems are rarely considered, largely because tundra fires occur infrequently on the modern landscape. We present paleoecological data that indicate frequent tundra fires in northcentral Alaska between 14,000 and 10,000 years ago. Charcoal and pollen from lake sediments reveal that ancient birch-dominated shrub tundra burned as often as modern boreal forests in the region, every 144 years on average (+/- 90 s.d.; n = 44). Although paleoclimate interpretations and data from modern tundra fires suggest that increased burning was aided by low effective moisture, vegetation cover clearly played a critical role in facilitating the paleofires by creating an abundance of fine fuels. These records suggest that greater fire activity will likely accompany temperature-related increases in shrub-dominated tundra predicted for the 21(st) century and beyond. Increased tundra burning will have broad impacts on physical and biological systems as well as on land-atmosphere interactions in the Arctic, including the potential to release stored organic carbon to the atmosphere.


Assuntos
Ecossistema , Fogo/história , Paleografia , Desenvolvimento Vegetal , Árvores/crescimento & desenvolvimento , Alaska , Regiões Árticas , Monitoramento Ambiental , História do Século XX , História do Século XXI , História Antiga
14.
Am Nat ; 167(5): E117-39, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16671005

RESUMO

Are there empirical regularities in the shapes of letters and other human visual signs, and if so, what are the selection pressures underlying these regularities? To examine this, we determined a wide variety of topologically distinct contour configurations and examined the relative frequency of these configuration types across writing systems, Chinese writing, and nonlinguistic symbols. Our first result is that these three classes of human visual sign possess a similar signature in their configuration distribution, suggesting that there are underlying principles governing the shapes of human visual signs. Second, we provide evidence that the shapes of visual signs are selected to be easily seen at the expense of the motor system. Finally, we provide evidence to support an ecological hypothesis that visual signs have been culturally selected to match the kinds of conglomeration of contours found in natural scenes because that is what we have evolved to be good at visually processing.


Assuntos
Evolução Cultural , Percepção de Forma , Idioma , Paleografia , Simbolismo , Humanos
15.
Science ; 305(5680): 30-3, 2004 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-15232083
17.
18.
Science ; 298(5600): 1984-7, 2002 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-12471256

RESUMO

A cylinder seal and carved greenstone plaque bearing glyphs dating to approximately 650 B.C. have been uncovered near the Olmec center of La Venta in Tabasco, Mexico. These artifacts, which predate others containing writing, reveal that the key aspects of the Mesoamerican scripts were present in Olmec writing: the combination of pictographic and glyphic elements to represent speech; the use of the sacred 260-day calendar; and the connection between writing, the calendar, and kingship. They imply that Mesoamerican writing originated in the La Venta polity.


Assuntos
Arqueologia , Cultura , Redação/história , História Antiga , Humanos , México , Paleografia
19.
Am J Phys Anthropol ; 117(4): 310-8, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11920366

RESUMO

The writing sheets made with strips from the stem (caulis) of papyri (Cyperus papyrus) are one of the most ingenious products of ancient technology. We extracted DNA from samples of modern papyri varying in age from 0-100 years BP and from ancient specimens from Egypt, with an age-span from 1,300-3,200 years BP. The copy number of the plant chloroplast DNA in the sheets was determined using a competitive PCR system designed on the basis of a short (90 bp) tract of the chloroplast's ribulose bisphosphate carboxylase large subunit (rbcL) gene sequence. The results allowed us to establish that the DNA half-life in papyri is about 19-24 years. This means that the last DNA fragments will vanish within no more than 532-672 years from the sheets being manufactured. In a parallel investigation, we checked the archaeological specimens for the presence of residual DNA and determined the extent of racemization of aspartic (Asp) acid in both modern and ancient specimens, as a previous report (Poinar et al. [1996], Science 272:864-866) showed that racemization of aspartic acid and DNA decay are linked. The results confirmed the complete loss of authentic DNA, even in the less ancient (8th century AD) papyri. On the other hand, when the regression for Asp racemization rates in papyri was compared with that for human and animal remains from Egyptian archaeological sites, it proved, quite surprisingly, that the regressions are virtually identical. Our study provides an indirect argument against the reliability of claims about the recovery of authentic DNA from Egyptian mummies and bone remains.


Assuntos
Cyperus/genética , DNA de Plantas/isolamento & purificação , Hominidae/genética , Manuscritos como Assunto/história , Paleografia , Isomerases de Aminoácido/isolamento & purificação , Animais , Arqueologia/métodos , Ácido Aspártico/metabolismo , Osso e Ossos/química , Antigo Egito , História Antiga , Humanos , Múmias , Reação em Cadeia da Polimerase
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