1,721,573 research outputs found
The First World War of Italian geologists. Between patriotic interventionism and objective pragmatism
No full textScientific studies dealing with the intimate relationship between
geology and First World War appeared in Italy already during the
conflict, or in the first decade after the end of hostilities. In this note we
have focused on two leading Italian geologists, Enrico Fossa-Mancini
and Federico Sacco which dealt with the possible use and importance of
geology in military operations, from territorial defense, to detection of
optimal areas for large troop movements. Despite the similarity of the
subject, and the not excessive time interval between the scripts, the
works of the two authors show a dramatically different approach and
point of arrival. The analysis by Fossa-Mancini is more objective,
detached and pragmatic, being carried out with a ‘clear mind’ after the
end of the conflict. His study is polished and purposeful, identifying the
actions required in time of peace to ‘geologically’ prepare a nation to a
potential conflict. Differently, the analysis by Sacco does not take into
account the real situation highlighted by Fossa-Mancini (e.g. the
complete unpreparedness of the high Italians command in terms of
military use of geology), and uses his writing to exalt the primacy of the
Italian army in the consideration of geology in military conflicts. In
Sacco, geology and the study of the Italian natural territory it is expertly
used as a justification and reason for the war, which it is perceived by
the author as necessary, of liberation and redemption
'The vain speculation disillusioned by the sense': The Italian painter Agostino Scilla (1629-1700) called 'The Discoloured', and the correct interpretation of fossils as 'lithified organisms' that once lived in the sea
No full textThe search for the true nature and origin of fossils gave rise, starting about the beginning of the sixteenth century and
throughout the seventeenth century, to a heated debate between the supporters of the inorganic nature of these objects and
proponents of an interpretation of fossils as ex-vivi. Among the latter, a key figure is the Italian painter Agostino Scilla
(1629–1700), who represents one of the first naturalists who was able to accumulate substantial evidence to support the
interpretation of fossils as once-living marine organisms. The world view of Scilla and his real contribution to paleontology
are here analysed and contextualised, taking into account the state of knowledge characterising the time of his activities.
Scilla was not only a pioneer in the field of paleontology, but he prepared the groundwork for the achievement of milestone
geological concepts such as actualism, taphonomy and recognition of internal and external moulds (in the instance of nonrepresentation
of original hard parts); Scilla deserves further recognitio
From petrified snakes, through giant ‘foraminifers’, to extinct cephalopods. The early history of ammonite studies in the Italian peninsula
No full textAs a result of their intrinsic beauty and relative abundance in some Mesozoic deposits, ammonites have always attracted the
attention of scholars and curious people, with written testimonies that can be traced back to Pliny’s Naturalis Historiae of 75
AD. The mysterious and evocative charm enclosed behind these extinct cephalopod has made its influence felt on legends,
myths, necromancy, medicine, religion and literature, attracting the literary interest of authors such as Goethe, Scott, Schiller
and Salgari. Of particular interest is the evolution of scientific thought and interpretations that, over time, have groped to find
a place for these ‘difficult fossils’, suspended between the organic world and the stone. In the present work, I briefly discuss
the history of the study of ammonites in the Italian peninsula, during the period between the sixteenth and the late nineteenth
centuries. Initially interpreted as petrified snakes, and believed for a long time to be ‘giant’ ancestors of living and extinct
foraminifera, only in the nineteenth century, ammonites were definitively interpreted as extinct cephalopods, with the
recognition of their crucial importance for biostratigraphy
The theory of the Earth of the Barnabite cleric Ermenegildo Pini. A mostly unknown Italian catastrophist
No full textAt the turn of the seventeenth and nineteenth centuries, Earth sciences were in a period of heated debates,
with an arduous acquisition of basic principles for geology. Among the unresolved debates, was the wellknown
between Neptunists and Plutonists, and there was still disagreement between the supporters of a
catastrophic flood and a long permanence of the sea in areas currently occupied by emerged lands. In such
a climate of uncertainty appears the ‘Theory of the Earth’ of Ermenegildo Pini, an Italian Barnabite cleric.
Pini was a many-faceted figure, including naturalist-scientist and technician, with interests ranging from
architecture and engineering to natural sciences sensu lato. As a Diluvialist and a Neptunist, Pini strongly
rejected the igneous theory – with Earth completely molten in origin – preferring instead one involving a
fluidity in water and formation of ‘primary mountains’ due of centrifugal acceleration induced by Earth’s
rotation. Alternatively, the so-called ‘transitional’ and ‘secondary’ mountains were entirely attributed to the
rapid, catastrophic and universal flood literally interpreted from the Holy Scriptures. Despite his strongly
theistic approach to the evolution of our planet, some of the intuitions and methodological approaches of
Pini are extremely interesting and worthy of review and renewed discussion
Reviewing the term uniformitarianism in modern earth sciences
No full textUniformitarianism is a classical term of the geological sciences, coined in 1832 by Whewell to indicate a specific part of Lyell's hypothesis. However, over the years uniformitarianism has been used with different meanings, fi- nally becoming synonymous with the entire theoretical system proposed by Lyell in his Principles. The popularity of this term and its frequently kaleidoscopic usage in the literature may be due in large part to the apparent sim- plicity of the “principle” of uniformitarianism. This is often summarized by the classical adage “the present is the key to the past”, a reductionist motto that has been passed through many generations of Earth scientists. In the text that follows, the major revisions of the term by Gould, Mayr and Rudwick are discussed in detail. These re- visions are used as solid epistemological basis for understanding the countless “shades of meaning” attributed to the term over time, and the main reasons that led to the overgrowth of a semantic chaos; one that poorly fits a modern scientific discipline.
Apart from the “invariance of natural laws” in space and time (the basic assumptions made in all scientific disci- plines), all remaining “principles” historically related to, or imbedded within uniformitarianism, have been defin- itively falsified. Even the “Uniformity of process”, which is essentially coincident with the term “actualism”, can be applied only to certain categories of products and processes (or to some particular stages in the evolution of our planet). In many cases, an extension of a current process to the past and vice versa is not warranted, in view of the crucial importance played by “configurational causes” during the evolution of our planet.
On the whole the analysis carried out highlights a real need to reconsider and investigate the epistemological un- derpinning of the Earth sciences, with one main effort aimed at solid preparation of young geologists, beginning with the basic courses of university education
Disparity versus diversity in ankylosaurid dinosaurs. Explored morphospace indicates two separate evolutive radiations
No full textAnkylosaurid ankylosaurs were armoured wide-bodied, rotund herbivores ornithischian dinosaurs notable for their weaponized tails and the presence of peculiar osteoderms. In this contribution I present the first diversity vs. disparity analysis in ankylosiaurids, using as a base the dataset from a recent published phylogeny for the clade. As already found recently in stegosaurs, the disparity as total variance results quite decoupled with respect to diversity through time, whereas the disparity obtained as sum of ranges appear very well coupled with the trend in diversity. Considering the disparity as sum of ranges as an indication of the total amount of the occupied morphospace the results indicate that, in the ankylosaurids, to an increase in the number of taxa corresponds a proportional increase in the explored morphospace. The study shows that the attainment of the maximum morphospace saturation in ankylosiaurids is at least bimodal. This indicates two separate evolutionary radiations for ankylosaurids, one between Albian and Cenomanian and a second one in the Campanian, separated by a crisis both in terms of number of species and of explored morphologies. Ankylosaurids were thus characterized by quite low diversity an morphological disparity well before the final extinction at the K-Pg boundary
“Per tremoto o per sostegno manco”. The Geology of Dante Alighieri’s Inferno
No full textThe purpose of the present paper is to analyse the geological elements and references found in Dante Alighieri's Inferno, which have never been treated in complete and comprehensive manner. Dante used wisely and in a unique manner the elements of nature, especially of landscape, to build the material foundation on which the fiction of the underworld journey is based. Specific kinds of rocks, steep cliffs, landslide bodies, lakes of hydrothermal water, waterfalls, become basic material in the hands of the Florentine poet, on which to base metaphors and similes. In Dante's Inferno there are references to hydrogeology, earthquakes, mountain structures, deposition of travertine, landscape modelling, meteorological phenomena, structure of the Earth and of the entire cosmos. The grandeur and mastery of Dante lies in being able to communicate, in short lines, the strong separation between scientific facts of natural phenomena and their use for aesthetic, poetic, political, and even ethical purposes. In dealing with complex issues such as the 'geophysical equilibrium' and the reason for the current distribution of land and ocean, Dante does not simply accept the theories of Aristotle (as stated by several exegetes) but shows a critical and deep analysis in the field of geology sensu lato, considering and preferring the phenomenal datum to the abstract theories. The work of Dante and his contemporaries did not impersonate the 'dark period' for science, as found in many interpretations of the Middle Ages, but the cultural context where those questions were posed which served as foundation and propellant for the subsequent 'scientific revolution
Gut microbiota as a trigger of accelerated directional adaptive evolution. Acquisition of herbivory in the context of extracellular vesicles, microRNAs and inter-kingdom crosstalk
Full text linkAccording to a traditional view, the specific diet in vertebrates is one of the key factors
structuring the composition of the gut microbiota. In this interpretation, the microbiota
assumes a subordinate position, where the larger host shapes, through evolution
and its fitness, the taxonomical composition of the hosted microbiota. The present
contribution shows how the evolution of herbivory, framed within the new concept of
holobiont, the possibility of inter-kingdom crosstalk and its epigenetic effects, could
pave the way to a completely reversed interpretation: instead of being passively shaped,
the microbiota can mold and shape the general host body structure to increase its
fitness. Central elements to consider in this context are the inter-kingdom crosstalk, the
possibility of transporting RNAs through nanovesicles in feces from parents to offspring,
and the activation of epigenetic processes passed on vertically from generation to
generation. The new hypothesis is that the gut microbiota could play a great role in
the macroevolutionary dynamics of herbivorous vertebrates, causing directly through
host-microbiota dialog of epigenetic nature (i.e., methylation, histone acetylation, etc.),
major changes in the organisms phenotype. The vertical exchange of the same microbial
communities from parents to offspring, the interaction of these microbes with fairly
uniform genotypes, and the socially restricted groups where these processes take
place, could all explain the reasons why herbivory has appeared several time (and
independently) during the evolution of vertebrates. The new interpretation could also
represent a key factor in understanding the convergent evolution of analogous body
structures in very distant lineages
Palaeoecology before ecology. The rise of actualism, palaeoenvironment studies and palaeoclimatology in the Italian panorama between the fourteenth and eighteenth centuries
No full textThe systematic use of fossil and sedimentological characters in palaeoenvironmental, palaeoecological and palaeoclimatic reconstructions is a fairly recent breakthrough of Earth Sciences. Traditionally, the works by James Hutton and Charles Lyell are viewed as true milestones of geology and the first coherent reasoning in the palaeoecologic context, as a necessary result of the new ‘doctrine’ of actualism. However, the foundation for actualistic reasoning, and their genuine use to interpret the fossil deposits, are clearly found in the writings of Italian naturalists more than four centuries before the publication of The Principles. In this paper, the first seeds of actualistic and palaeoecological reasoning, detectable in the Italian panorama between the thirteenth and early nineteenth century, are discussed. As early as the thirteenth century, authors like Ristoro d’Arezzo used sedimentary processes currently observed to interpret the fossil deposits. Naturalists as Marsili and Donati emphasized the close correspondence between the current seabed, abundance and distribution of species, and the conditions observed in the fossil deposits. Targioni Tozzetti surprises correctly interpreting the remains of large vertebrates in Italy as belonging to animals endemic of the Peninsula, using this evidence to infer a warmer climate in the past and surprising readers of the day with the modernity of his ideas. These great naturalists not only imagined a completely different flora based on the fossil record, but attributed the warmer climate of the past to changes in the sea level, thus providing arguments used by Lyell some eighty years later to explain climate change over geological time
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