Història Natural i curiositat humana

Abstract not availabl

Paleontological interest of karstic deposits from the Gymnesic and Pityusic Islands

El coneixement sobre les faunes vertebrades del Plioce i Pleistoce de les Gimnesies i de les Pitiüses prové principalment de I'estudi de materials fossils obtinguts en diposits carstics. El seu registre fossilífer cobreix el Plioce i el Pleistoce, un espectre temporal de devers 5,5 milions d'anys. Myotragus, un bovid endemic de les Gimnesies, I'únic mamífer de talla mitjana d'aquestes illes, és una especie-clau per a la interpretació dels processos evolutius. L'estudi del seu registre fossilífer documenta que la discussió entre puntuacionisme i gradualisme és artefactual. El registre fossilífer de les Pitiüses és menys complet peral Plioce i Pleistoce inferior. Pero les faunes fossils del Pleistoce superior de les Pitiüses estan molt ben documentades i constitueixen I'anomalia faunística més gran de totes les illes mediterranies. Aquesta anomalia demostra que hi va esdevenir una catastrofe natural, la qual va causar I'extinció de tots els vertebrats terrestres llevat d'una especie de sargantana Lacertidae, i de devers 314 parts dels gasteropodes terrestres. Posteriorment en aquest esdeveniment les illes Pitiüses no foren recolonitzades per altres vertebrats terrestres, Ilevat de per ocells i rates pinyades. Probablement I'actual sistema de corrents marines que actualment es troba entre les Pitiüses i la Península Iberica ja existia en el passat, i degué evitar la dispersió ultramarina de vertebrats terrestres.The vertebrate faunas from the Pliocene and Pleistocene of the Gymnesic and the Pityusic lslands are nowadays quite well-known. The current knowledge is mainly based on the study of fossil material which was obtained from karstic deposits. Its stratigraphic range covers the whole Plio/Pleistocene, a time range of about 5.5 My. The bovid Myotragus of the Gymnesic lslands provides a paradigm for the study of evolutionary processes and shows that the distinction between two evolutionary models, punctuated equilibrium and gradualitism, often regarded as opposing, is an artifact. The fossil record of the Pityusic Islands is less complete from the Pliocene and Lower Pleistocene. But the Upper Pleistocene is well documented in the Pityusics and contains an exceptional faunistic anomaly if compared with al1 the other Mediterranean islands. This anomaly is demostrative for a natural dkaster causing the extinction of al1 the endemic land vertebrates, excepting a lacertid lizard, and nearly al1 the land gastropods. After this event the Pityusic lslands were not recolonised by land vertebrates, other than by the flying ones, ¡.e., birds and bats. Probably a system of marine currents similar to the existing currently was already achieved, and prevent overseas immigration of land non-flying vertebrates

Concordance between school outcomes and developmental follow-up results of very preterm and/or low birth weight children at the age of 5 years

Contains fulltext : 53593.pdf (publisher's version ) (Closed access)INTRODUCTION: Long-term follow-up studies have revealed a high frequency of developmental disturbances in preterm survivors of neonatal intensive care who were formerly considered to be non-disabled. These developmental disturbances interfere with the acquisition of everyday skills and, in particular, with normal school functioning. METHODS: Developmental and school outcomes of 355 children, age 5 years at the time of the study, who had a mean gestational age of 30.2 weeks (SD: 1.95) and a mean birth weight of 1272 g (SD: 326) were investigated. Children with severe handicaps were excluded from the study. Perinatal data, information from a parental and school questionnaire and data from standardized developmental tests were used to explain the differences. RESULTS: An agreement of 72% was found between developmental follow-up and school outcomes. Normal developmental results but problematic school outcomes were found for 15% of the children tested. There were more boys than girls in this latter group as well as small-for-gestational-age children with relatively poor motor or language development. The schools had not identified problems in 13% of the children, whereas their developmental outcomes were problematic. These children had less neonatal morbidity and relatively higher IQ's than children who also had problematic developmental outcomes but who had been signalled as problematic by their schools. CONCLUSIONS: Schools have a good insight in the school functioning of children who are developing well and of children with the lowest developmental scores and the most complicated neonatal histories. How school and developmental outcomes interrelate in the in-between groups remains a challenging question that could be answered by following these children throughout their school career

Les Hipparion du Portugal

This paper is concerned with Hipparion from Ribatejo, Portugal, and with the stratigraphy of the Neogene series of this region. The first two chapters are an introduction and an historical review. Paleontological study includes both a revision of the specimens accounted by ROMAN (1907) and the description of new material. Two forms were recognized, an early H. cf. primigenium, lower Vallesian in age, NM 9 mammal unit (from Archino, Vila Nova da Rainha, Aveiras de Cima), and a more advanced H. primigenium cf. melendezi. Upper Vallesian, NM 10 (possibly lowermost Turolian, NM 11) (at Azambujeira and Marmeleira). A synthesis of Middle and Upper Miocene from Ribatejo is also presented. Levels with H. p. cf. melendezi are somewhat older than «Upper Pontian», as it was previously acknowledged, they attain at the best the lowermost Turolian (approximately corresponding to «Upper Pontian»). Even higher levels may be Turolian in age, though they are not yet accurately dated. Almost all the localities are shown (tableau 11) according to its stratigraphical position; age, correspondance to mammal units from NM 5 to NM 10 (and may be also from NM 11 to NM 12), and correlation with marine formations near Lisbon are also taken in account. The stratigraphical position of localities such as Póvoa de Santarém, Quinta do Marmelal, Pero Filho, Azambujeira (lower levels), and Fonte do Pinheiro was revised; the stratigraphical position of Marmeleira was ascertained. The localities so far known correspond to NM 5 (?), NM 6, NM 8, NM 9, NM 10 and possibly to NM II and NM 12. A new interpretation (M. T. ANTUNES) of localities with oysters from Ribatejo allows a better correlation with vertebrate localities. Relationships with Serravallian transgression seem well established. Only two localities, Vila Nova da Rainha and Foz do Alviela, may possibly be correlated to V-b division of Lisbon (Langhian) with «Hispanotherium fauna». All the other localities are younger than Serravallian oyster beds. Undirect correlation shows that NM 6 localities are somewhat younger than the apogee ef Serravallian transgression (corresponding approximately to Blow's N 11 to N 13 zones based on planctonic foraminifera)

Interès paleontològic dels jaciments càrstics de les Gimnèsies i les Pitiüses

[cat] El coneixement sobre les faunes vertebrades del Pliocè i Pleistocè de les Gimnèsies i de les Pitiüses prové principalment de l’estudi de materials fòssils obtinguts en dipòsits càrstics. El seu registre fossilífer cobreix el Pliocè i el Pleistocè, un espectre temporal de devers 5,5 milions d'anys. Myotragus, un bòvid endèmic de les Gimnèsies, l’únic mamífer de talla mitjana d'aquestes illes, és una espècie-clau per a la interpretació dels processos evolutius. L'estudi del seu registre fossilífer documenta que la discussió entre puntuacionisme i gradualisme és artefactual. El registre fossilífer de les Pitiüses és menys complet per al Pliocè i Pleistocè inferior. Però les faunes fòssils del Pleistocè superior de les Pitiüses estan molt ben documentades i constitueixen l’anomalia faunística més gran de totes les illes mediterrànies. Aquesta anomalia demostra que hi va esdevenir una catàstrofe natural, la qual va causar l’extinció de tots els vertebrats terrestres llevat d'una espècie de sargantana Lacertidae, i de devers 314 parts dels gasteròpodes terrestres. Posteriorment en aquest esdeveniment les illes Pitiüses no foren recolonitzades per altres vertebrats terrestres, llevat de per ocells i rates pinyades. Probablement I'actual sistema de corrents marines que actualment es troba entre les Pitiüses i la Península Iberica ja existia en el passat, i degué evitar la dispersió ultramarina de vertebrats terrestres.[eng] The vertebrate faunas from the Pliocene and Pleistocene of the Gymnesic and the Pityusic lslands are nowadays quite well-known. The current knowledge is mainly based on the study of fossil material which was obtained from karstic deposits. Its stratigraphic range covers the whole Plio/Pleistocene, a time range of about 5.5 My. The bovid Myotragus of the Gymnesic lslands provides a paradigm for the study of evolutionary processes and shows that the distinction between two evolutionary models, punctuated equilibrium and gradualitism, often regarded as opposing, is an artifact. The fossil record of the Pityusic Islands is less complete from the Pliocene and Lower Pleistocene. But the Upper Pleistocene is well documented in the Pityusics and contains an exceptional faunistic anomaly if compared with al1 the other Mediterranean islands. This anomaly is demostrative for a natural disaster causing the extinction of al1 the endemic land vertebrates, excepting a lacertid lizard, and nearly all the land gastropods. After this event the Pityusic lslands were not recolonised by land vertebrates, other than by the flying ones, i.e., birds and bats. Probably a system of marine currents similar to the existing currently was already achieved, and prevent overseas immigration of land non-flying vertebrates

Y-Chromosome Based Evidence for Pre-Neolithic Origin of the Genetically Homogeneous but Diverse Sardinian Population: Inference for Association Scans

The island of Sardinia shows a unique high incidence of several autoimmune diseases with multifactorial inheritance, particularly type 1 diabetes and multiple sclerosis. The prior knowledge of the genetic structure of this population is fundamental to establish the optimal design for association studies in these diseases. Previous work suggested that the Sardinians are a relatively homogenous population, but some reports were contradictory and data were largely based on variants subject to selection. For an unbiased assessment of genetic structure, we studied a combination of neutral Y-chromosome variants, 21 biallelic and 8 short tandem repeats (STRs) in 930 Sardinian males. We found a high degree of interindividual variation but a homogenous distribution of the detected variability in samples from three separate regions of the island. One haplogroup, I-M26, is rare or absent outside Sardinia and is very common (0.37 frequency) throughout the island, consistent with a founder effect. A Bayesian full likelihood analysis (BATWING) indicated that the time from the most recent common ancestor (TMRCA) of I-M26, was 21.0 (16.0–25.5) thousand years ago (KYA) and that the population began to expand 14.0 (7.8–22.0) KYA. These results suggest a largely pre-Neolithic settlement of the island with little subsequent gene flow from outside populations. Consequently, Sardinia is an especially attractive venue for case-control genome wide association scans in common multifactorial diseases. Concomitantly, the high degree of interindividual variation in the current population facilitates fine mapping efforts to pinpoint the aetiologic polymorphisms

The origins and persistence of Homo floresiensis on Flores: biogeographical and ecological perspectives

The finding of archaeological evidence predating 1 Ma and a small hominin species (Homo floresiensis) on Flores, Indonesia, has stimulated much research on its origins and ancestry. Here we take a different approach and examine two key questions – 1) how did the ancestors of H. floresiensis reach Flores and 2) what are the prospects and difficulties of estimating the likelihood of hominin persistence for over 1 million years on a small island? With regard to the first question, on the basis of the biogeography we conclude that the mammalian, avian, and reptilian fauna on Flores arrived from a number of sources including Java, Sulawesi and Sahul. Many of the terrestrial taxa were able to float or swim (e.g. stegodons, giant tortoises and the Komodo dragon), while the rodents and hominins probably accidentally rafted from Sulawesi, following the prevailing currents. The precise route by which hominins arrived on Flores cannot at present be determined, although a route from South Asia through Indochina, Sulawesi and hence Flores is tentatively supported on the basis of zoogeography. With regards to the second question, we find the archaeological record equivocal. A basic energetics model shows that a greater number of small-bodied hominins could persist on Flores than larger-bodied hominins (whether H. floresiensis is a dwarfed species or a descendent of an early small-bodied ancestor is immaterial here), which may in part explain their apparent long-term success. Yet the frequent tsunamis and volcanic eruptions in the region would certainly have affected all the taxa on the island, and at least one turnover event is recorded, when Stegodon sondaari became extinct. The question of the likelihood of persistence may be unanswerable until we know much more about the biology of H. floresiensis

The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia

Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35–50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the “20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/−17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted