Una visión personal del libro de ciencia

Tres de los escritores preferidos del autor de este artículo, a su vez escritor y científico, son Stephen Jay Gould, Richard Dawkins y Jared Diamond porque, según nos dirá, estos autores son capaces de construir hipótesis, reflejar inquietudes sociales a la vez que actuar como referentes históricos, del mismo modo como Dickens nos permite conocer la Inglaterra Victoriana. A continuación, incluye un sucinto análisis de la situación de la divulgación científica literaria e institucional en nuestro país

Estudi antropològic de les tombes de La Muntanyeta (Roda de Ter, Osona)

A causa de les adverses condicions en que es va realitzar I'excavació i del llarg període transcorregut des d'aquesta fins a la realització de l'estudi, el material que ens ha arribar esta molt deteriorar i aixó ens ha impedit de procedir a un estudi mètric acurat. S'ha mirar de quantificar al màxim el crani més ben conservar (el de l'individu M-1). Així, algunes mesures s'han pres per simetria en base a un craniograma orientar en I'eix bregma-lambda. S'ha localitzat un punt bregma teòric, unint les traces de sutura corona1 i sagital. Les mesures relacionades amb aquest punt craniomètric, han de ser considerades a títol orientatiu. Quan ha estat possible, el sexe s'ha determinar per I'índex corilo-ciàtic. Agraïm I'ajut del Dr. M. Hernández de la Secció d'Antropologia, Departament de Biologia Animal, Universitat de Barcelona

Molecular dating of caprines using ancient DNA sequences of Myotragus balearicus, an extinct endemic Balearic mammal

Background: Myotragus balearicus was an endemic bovid from the Balearic Islands (Western Mediterranean) that became extinct around 6,000-4,000 years ago. The Myotragus evolutionary lineage became isolated in the islands most probably at the end of the Messinian crisis, when the desiccation of the Mediterranean ended, in a geological date established at 5.35 Mya. Thus, the sequences of Myotragus could be very valuable for calibrating the mammalian mitochondrial DNA clock and, in particular, the tree of the Caprinae subfamily, to which Myotragus belongs. Results: We have retrieved the complete mitochondrial cytochrome b gene (1,143 base pairs), plus fragments of the mitochondrial 12S gene and the nuclear 28S rDNA multi-copy gene from a well preserved Myotragus subfossil bone. The best resolved phylogenetic trees, obtained with the cytochrome b gene, placed Myotragus in a position basal to the Ovis group. Using the calibration provided by the isolation of Balearic Islands, we calculated that the initial radiation of caprines can be dated at 6.2 ± 0.4 Mya. In addition, alpine and southern chamois, considered until recently the same species, split around 1.6 ± 0.3 Mya, indicating that the two chamois species have been separated much longer than previously thought. Conclusion: Since there are almost no extant endemic mammals in Mediterranean islands, the sequence of the extinct Balearic endemic Myotragus has been crucial for allowing us to use the Messinian crisis calibration point for dating the caprines phylogenetic tree

Look-alike humans identified by facial recognition algorithms show genetic similarities

We thank François Brunelle for providing the look-alike images. We thank CERCA Programme/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. This work was funded by the governments of Catalonia (2017SGR1080) and Spain (RTI2018-094049-B-I00, SAF2014-55000, and TIN2017-90124-P) and the Cellex Foundation. M.E. conceived and designed the study; R.S.J. M.R. C.A.G.-P. M.C.d.M. D.P. S.M. V.D. P.C. M.F.-B. I.O. C.L.-F. A.N. C.F.-T. D.A. F.M.S. X.B. A.V. and M.E. analyzed multiomics and questionnaire data; R.J. and M.E. wrote the manuscript with contributions and approval from all authors. M.E. is a consultant of Ferrer International and Quimatryx. S.M. is an employee of Ferrer International. C.F.-T. is chief technical officer of Herta Security.We thank François Brunelle for providing the look-alike images. We thank CERCA Programme/Generalitat de Catalunya and the Josep Carreras Foundation for institutional support. This work was funded by the governments of Catalonia (2017SGR1080) and Spain (RTI2018-094049-B-I00, SAF2014-55000, and TIN2017-90124-P) and the Cellex Foundation.The human face is one of the most visible features of our unique identity as individuals. Interestingly, monozygotic twins share almost identical facial traits and the same DNA sequence but could exhibit differences in other biometrical parameters. The expansion of the world wide web and the possibility to exchange pictures of humans across the planet has increased the number of people identified online as virtual twins or doubles that are not family related. Herein, we have characterized in detail a set of "look-alike" humans, defined by facial recognition algorithms, for their multiomics landscape. We report that these individuals share similar genotypes and differ in their DNA methylation and microbiome landscape. These results not only provide insights about the genetics that determine our face but also might have implications for the establishment of other human anthropometric properties and even personality characteristics

A new assemblage of late Neanderthal remains from Cova Simanya (NE Iberia)

This study presents an exceptional collection of 54 Late Pleistocene human remains that correspond to at least three Neanderthal individuals from Simanya Gran, the main gallery of Cova Simanya, located in the northeastern Iberian Peninsula. The collection comprised 53 unpublished remains that were unearthed during the 1970s and an additional tooth discovered during 2021 excavations. The specimens represent an adult with a small stature, a periadolescent aged approximately 11.5 years, and an immature individual aged approximately 7.7 years, thus offering a more complete demographic perspective. The collection encompasses diverse anatomical parts including upper and lower dentition, mandible, vertebrae, and limb bones from both the upper and lower extremities. Attempts to extract aDNA were unsuccessful. Renewed archaeological investigations at Cova Simanya have facilitated the reevaluation of the original stratigraphic context of these remains, leading to the discovery of the additional tooth, aligning with the periadolescent individual. This assemblage is currently the most extensive Neanderthal collection from the northeastern Mediterranean Iberia, offering invaluable insights into the morphology and evolutionary trajectory of Late Pleistocene hominins. Hence, Simanya Neanderthals will enhance our understanding of Neanderthal demographics and evolution, paving the way for an in-depth examination of the morphological diversity and evolutionary context of Iberian Neanderthals

Unraveling the Phylogenetic Relationships of the Eccoptochilinae, an Enigmatic Array of Ordovician Cheirurid Trilobites

The Cheiruridae are a diverse group of trilobites and several subfamilies within the clade have been the focus of recent phylogenetic studies. This paper focuses on the relationships of one of those subfamilies, the Ordovician Eccoptochilinae. We analyze sixteen species from six genera within the traditionally defined group, using the pilekiid Anacheirurus frederici as an outgroup. To assess the monophyly of the Eccoptochilinae seven sphaerexochine species, Kawina arnoldi, Sphaerexochus arenosus, S. atacius, S. latifrons, S. mirus, S. parvus, and S. scabridus were included in the analysis as well. The results of this analysis show that the genus Eccoptochile represents a paraphyletic grade and species traditionally assigned to Parasphaerexochus and Skelipyx plot within Pseudosphaerexochus. Also, representative species of Sphaerexochinae plot within the traditionally defined Eccoptochilinae, suggesting Eccoptochilinae itself is paraphyletic. To resolve this, we propose all species of Pseudosphaerexochus be placed within Sphaerexochinae and Eccoptochilinae be restricted to a monotypic Eccoptochile clavigera.This research was supported by NSF DEB-0716162

Bioprospecting Finds the Toughest Biological Material: Extraordinary Silk from a Giant Riverine Orb Spider

Background Combining high strength and elasticity, spider silks are exceptionally tough, i.e., able to absorb massive kinetic energy before breaking. Spider silk is therefore a model polymer for development of high performance biomimetic fibers. There are over 41.000 described species of spiders, most spinning multiple types of silk. Thus we have available some 200.000+ unique silks that may cover an amazing breadth of material properties. To date, however, silks from only a few tens of species have been characterized, most chosen haphazardly as model organisms (Nephila) or simply from researchers' backyards. Are we limited to ‘blindly fishing’ in efforts to discover extraordinary silks? Or, could scientists use ecology to predict which species are likely to spin silks exhibiting exceptional performance properties? Methodology We examined the biomechanical properties of silk produced by the remarkable Malagasy ‘Darwin's bark spider’ (Caerostris darwini), which we predicted would produce exceptional silk based upon its amazing web. The spider constructs its giant orb web (up to 2.8 m2) suspended above streams, rivers, and lakes. It attaches the web to substrates on each riverbank by anchor threads as long as 25 meters. Dragline silk from both Caerostris webs and forcibly pulled silk, exhibits an extraordinary combination of high tensile strength and elasticity previously unknown for spider silk. The toughness of forcibly silked fibers averages 350 MJ/m3, with some samples reaching 520 MJ/m3. Thus, C. darwini silk is more than twice tougher than any previously described silk, and over 10 times better than Kevlar®. Caerostris capture spiral silk is similarly exceptionally tough. Conclusions Caerostris darwini produces the toughest known biomaterial. We hypothesize that this extraordinary toughness coevolved with the unusual ecology and web architecture of these spiders, decreasing the likelihood of bridgelines breaking and collapsing the web into the river. This hypothesis predicts that rapid change in material properties of silk co-occurred with ecological shifts within the genus, and can thus be tested by combining material science, behavioral observations, and phylogenetics. Our findings highlight the potential benefits of natural history–informed bioprospecting to discover silks, as well as other materials, with novel and exceptional properties to serve as models in biomimicry.Primary funding for this work came from the Slovenian Research Agency (grant Z1-9799-0618-07 to I. Agnarsson), the National Geographic Society (grant 8655-09 to the authors), and the National Science Foundation (grants DBI-0521261, DEB-0516038 and IOS-0745379 to T. Blackledge). Additional funding came from the European Community 6th Framework Programme (a Marie Curie International Reintegration Grant MIRG-CT-2005 036536 to M. Kuntner). The 2001 field work was supported by the Sallee Charitable Trust grant to I. Agnarsson and M. Kuntner and by a United States National Science Foundation grant (DEB-9712353) to G. Hormiga and J. A. Coddington. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe