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1
Michie, MG. "Distribution of foraminifera in a macrotidal tropical estuary: Port Darwin, Northern Territory of Australia." Marine and Freshwater Research 38, no. 2 (1987): 249. http://dx.doi.org/10.1071/mf9870249.
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The foraminifera are distributed throughout Port Darwin and differ according to biotope. The tidal flat and coral reef biotopes are basically undisturbed, and contain species of foraminifera typical of those environments. Turbidity is responsible for a lower diversity of the reefal facies, and particularly affects those species with symbiotic algae. The reworked biotope contains foraminifera more typical of the shallow continental shelf. Strong tidal currents associated with the large tidal range are responsible for the reworking of sediments and foraminifera1 tests from inside and outside Port Darwin.
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GILLESPIE, METTE K., WENDY LAWSON, WOLFGANG RACK, BRIAN ANDERSON, DONALD D. BLANKENSHIP, DUNCAN A. YOUNG, and JOHN W. HOLT. "Geometry and ice dynamics of the Darwin–Hatherton glacial system, Transantarctic Mountains." Journal of Glaciology 63, no. 242 (October 30, 2017): 959–72. http://dx.doi.org/10.1017/jog.2017.60.
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ABSTRACTThe Darwin–Hatherton Glacial system (DHGS) connects the East Antarctic Ice Sheet (EAIS) with the Ross Ice Shelf and is a key area for understanding past variations in ice thickness of surrounding ice masses. Here we present the first detailed measurements of ice thickness and grounding zone characteristics of the DHGS as well as new measurements of ice velocity. The results illustrate the changes that occur in glacier geometry and ice flux as ice flows from the polar plateau and into the Ross Ice Shelf. The ice discharge and the mean basal ice shelf melt for the first 8.5 km downstream of the grounding line amount to 0.24 ± 0.05 km3 a−1 and 0.3 ± 0.1 m a−1, respectively. As the ice begins to float, ice thickness decreases rapidly and basal terraces develop. Constructed maps of glacier geometry suggest that ice drainage from the EAIS into the Darwin Glacier occurs primarily through a deep subglacial canyon. By contrast, ice thins to <200 m at the head of the much slower flowing Hatherton Glacier. The glaciological field study establishes an improved basis for the interpretation of glacial drift sheets at the link between the EAIS and the Ross Ice Sheet.
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Vincent, Warwick F., and Clive Howard-Williams. "Nitrate-rich inland waters of the Ross Ice Shelf region, Antarctica." Antarctic Science 6, no. 3 (September 1994): 339–46. http://dx.doi.org/10.1017/s0954102094000519.
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Nutrient and major ion concentrations were measured in surface water samples from lakes, ponds and streams at sites 30–320 km south of McMurdo Sound: the Darwin Glacier region (79.7–80.0°S), Pyramid Trough in the southern Dry Valleys (78.2°S), and the McMurdo Ice Shelf ablation zone (77.8–78.4°S). These aquatic environments ranged from dilute meltwaters (conductivity <0.05 mS cm−1) to concentrated brines (>50 mS cm−1). The lowest nitrate concentrations were recorded at the sites closest to the seasonally open waters of the Ross Sea. Much higher values (100–142000mg NO3–Nm−3) were recorded at sites further south. These observations support the hypothesis that NO3 precipitation over Antarctica is of stratospheric rather than coastal marine origin. The nitrogen-rich waters contained chloride and nitrate in the ratio 5.45g Cl:1g N (C.V.=8.4%) which is within the range for Antarctic snow, and indicative of nitrate enrichment by freeze concentration processes. Cyanobacterial mats were conspicuous elements of the biota across the full range of salinities, and were usually dominated by oscilatoriacean species. Nitrogen-fixing cyanobacteria and diatoms were also represented in these benthic microbial communities at the more northern sites, but were absent from all samples from the Darwin Glacier region.
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Zawar-Reza, Peyman, Steve George, Bryan Storey, and Wendy Lawson. "Summertime boundary layer winds over the Darwin–Hatherton glacial system, Antarctica: observed features and numerical analysis." Antarctic Science 22, no. 6 (December 2010): 619–32. http://dx.doi.org/10.1017/s0954102010000817.
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AbstractThree temporary Automatic Weather Stations measured summertime surface layer climate over the Darwin–Hatherton Glacial system. These data were used to test a Polar optimized Weather Research and Forecasting model (Polar-WRF) simulation for December as a case study. Observations show differences in hourly averaged solar and net all-wave radiation between white ice and blue ice areas (BIAs). Although the down-welling solar radiation is higher over the white ice region, the net all-wave energy is higher over the BIA. Derived albedo for each surface type confirms that the blue ice areas have lower albedo. Also, the hourly averaged temperatures are higher at lower elevation stations, creating a gradient towards the Ross Ice Shelf. Analysis shows that there is a diurnal oscillation in strength and intensity of the katabatic wind. The two lower stations register a distinct reversal of wind direction in the early afternoon due to intrusion of an anabatic circulation. Anabatic winds are not prevalent further up the Darwin Glacier. A high-resolution Polar-WRF simulation as a case study shows good agreement with observations. The December 2008 case study is characterized by a strong south-westerly katabatic wind over Hatherton, whereas the flow over Lower Darwin was diurnally reversing. Polar-WRF shows that the katabatic front advanced and retreated periodically between Hatherton and Lower Darwin.
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SHALOVENKOV, N. N. "Non-native zoobenthic species at the Crimean Black Sea Coast." Mediterranean Marine Science 18, no. 2 (July 17, 2017): 260. http://dx.doi.org/10.12681/mms.1925.
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More than 40 non-native species have been registered in the zoobenthos of the Black Sea. Only, five alien species, the Crustacea, Rhithropanopeus harrisii (Gould, 1841) and Rhithropanopeus harrisii (Gould, 1841), and the Mollusca, Rapana venosa (Valenciennes, 1846), Mya arenaria (Linne, 1758) and Anadara kagoshimensis (Tokunaga, 1906), were recorded in the benthos on the Crimean shelf between 1999-2014. The blood-cockle A. kagoshimensis had settled on many sites of the Black Sea shelf in the past forty years. The first detection (1999) at the Crimean coast and the temporal variability of this mollusc’s population coincided with the tendency in variability of the water temperature in the area.The five alien species had spatial aggregation and their occurrence did not exceed 23 % in the boundaries of the distribution sites. An increasing trend for their abundance in the last five - seven years was observed. These years were characterized by temperature rise in the surface layer of coastal waters. Similar patterns have been observed in the interannual variability of the biomass and abundance ratio of aliens to native for all zoobenthic taxonomic groups, i.e. of dominance index of alien species.The low level of the dominance index of the introduced species is indicative of low impact on the diversity of the benthic communities of the Crimea coast, i.e. on the scale of the metacommunity. With the exception of the R. venosa, they exhibited lower biomass and abundance along the Crimean coast shelf as opposed to other areas of the Black Sea shelf. Occasionally, the dominance index for the barnacle Amphibalanus improvisus (Darwin, 1854) could be high, a fact attributed to the low biomass and abundance of other benthic species.
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Markl, Hubert. "Misunderstanding and Misuse of Darwinism." European Review 18, no. 3 (July 2010): 329–45. http://dx.doi.org/10.1017/s1062798710000062.
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The reason why I wavered a bit with this topic is that, after all, it has to do with Darwin, after a great Darwin year, as seen by a German scientist. Not that Darwin was very adept in German: Gregor Mendel’s ‘Versuche über Pflanzenhybriden’ (Experiments on Plant Hybrids) was said to have stayed uncut and probably unread on his shelf, which is why he never got it right with heredity in his life – only Gregory Bateson, Ronald A. Fisher, and JBS Haldane, together with Sewall Wright merged evolution with genetics. But Darwin taught us, nevertheless, in essence why the single human species shows such tremendous ethnic diversity, which impresses us above all through a diversity of languages – up to 7000 altogether – and among them, as a consequence, also German, my mother tongue, and English. It would thus have been a truly Darwinian message, if I had written this article in German. I would have called that the discommunication function of the many different languages in humans, which would have been a most significant message of cultural evolution, indeed. I finally decided to overcome the desire to demonstrate so bluntly what cultural evolution is all about, or rather to show that nowadays, with global cultural progress, ‘the world is flat’ indeed – even linguistically. The real sign of its ‘flatness’ is that English is used everywhere, even if Thomas L. Friedman may not have noticed this sign. But I will also come back to that later, when I hope to show how Darwinian principles connect both natural and cultural evolution, and how they first have been widely misunderstood as to their true meaning, and then have been terribly misused – although more so by culturalists, or some self-proclaimed ‘humanists’, rather than by biologists – or at least most of them. Let me, however, quickly add a remark on human languages. That languages even influence our brains and our thinking, that is: how we see the world, has first been remarked upon by Wilhelm von Humboldt and later, more extensively so, by Benjamin Whorf. It has recently been shown by neural imaging – for instance by Angela Friederici – that one’s native language, first as learned from one’s mother and from those around us when we are babies, later from one’s community of speakers, can deeply impinge on a baby’s brain development and stay imprinted in it throughout life, even if language is, of course, learned and not fully genetically preformed. This shows once more how deep the biological roots are that ground our cultures, according to truly Darwinian principles, even if these cultures are completely learned.
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Storey, B. C., D. Fink, D. Hood, K. Joy, J. Shulmeister, M. Riger-Kusk, and M. I. Stevens. "Cosmogenic nuclide exposure age constraints on the glacial history of the Lake Wellman area, Darwin Mountains, Antarctica." Antarctic Science 22, no. 6 (December 2010): 603–18. http://dx.doi.org/10.1017/s0954102010000799.
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AbstractWe present direct terrestrial evidence of ice volume change of the Darwin and Hatherton glaciers which channel ice from the Transantarctic Mountains into the Ross Ice Shelf. Combining glacial geomorphology with cosmogenic exposure ages from 25 erratics indicates a pre-LGM ice volume at least 600 m thicker than current Hatherton ice elevation was established at least 2.2 million years ago. In particular, five erratics spread across a drift deposit at intermediate elevations located below a prominent moraine feature mapped previously as demarcating the LGM ice advance limits, give a well-constrained single population with mean 10Be age of 37.0 ± 5.5 ka (1σ). At lower elevations of 50–100 m above the surface of Lake Wellman, a further five samples from within a younger drift deposit range in exposure age from 1 to 19 ka. Our preferred age model interpretation, which is partly dependent on the selection of a minimum or maximum age-elevation model, suggests that LGM ice volume was not as large as previously estimated and constrains LGM ice elevation to be within ± 50 m of the modern Hatherton Glacier ice surface, effectively little different from what is observed today.
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Denton, George H., James G. Bockheim, Scott C. Wilson, and Minze Stuiver. "Late Wisconsin and Early Holocene Glacial History, Inner Ross Embayment, Antarctica." Quaternary Research 31, no. 2 (March 1989): 151–82. http://dx.doi.org/10.1016/0033-5894(89)90004-5.
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AbstractLateral drift sheets of outlet glaciers that pass through the Transantarctic Mountains constrain past changes of the huge Ross ice drainage system of the Antarctic Ice Sheet. Drift stratigraphy suggests correlation of Reedy III (Reedy Glacier), Beardmore (Beardmore Glacier), Britannia (Hatherton/Darwin Glaciers), Ross Sea (McMurdo Sound), and “younger” (Terra Nova Bay) drifts; radiocarbon dates place the outer limits of Ross Sea drift in late Wisconsin time at 24,000–13,000 yr B.P. Outlet-glacier profiles from these drifts constrain late Wisconsin ice-sheet surface elevations. Within these constraints, we give two extreme late Wisconsin reconstructions of the Ross ice drainage system. Both show little elevation change of the polar plateau coincident with extensive ice-shelf grounding along the inner Ross Embayment. However, in the central Ross Embayment one reconstruction shows floating shelf ice, whereas the other shows a grounded ice sheet. Massive late Wisconsin/Holocene recession of grounded ice from the western Ross Embayment, which was underway at 13,040 yr B.P. and completed by 6600-6020 yr B.P., was accompanied by little change in plateau ice levels inland of the Transantarctic Mountains. Sea level and basal melting probably controlled the extent of grounded ice in the Ross Embayment. The interplay between the precipitation (low late Wisconsin and high Holocene values) and the influence of grounding on outlet glaciers (late Wisconsin thickening and late Wisconsin/Holocene thinning, with effects dying out inland) probably controlled minor elevation changes of the polar plateau.
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Wild, Christian T., Oliver J. Marsh, and Wolfgang Rack. "Differential interferometric synthetic aperture radar for tide modelling in Antarctic ice-shelf grounding zones." Cryosphere 13, no. 12 (November 29, 2019): 3171–91. http://dx.doi.org/10.5194/tc-13-3171-2019.
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Abstract. Differential interferometric synthetic aperture radar (DInSAR) is an essential tool for detecting ice-sheet motion near Antarctica's oceanic margin. These space-borne measurements have been used extensively in the past to map the location and retreat of ice-shelf grounding lines as an indicator for the onset of marine ice-sheet instability and to calculate the mass balance of ice sheets and individual catchments. The main difficulty in interpreting DInSAR is that images originate from a combination of several SAR images and do not indicate instantaneous ice deflection at the times of satellite data acquisitions. Here, we combine the sub-centimetre accuracy and spatial benefits of DInSAR with the temporal benefits of tide models to infer the spatio-temporal dynamics of ice–ocean interaction during the times of satellite overpasses. We demonstrate the potential of this synergy with TerraSAR-X data from the almost-stagnant southern McMurdo Ice Shelf (SMIS). We then validate our algorithm with GPS data from the fast-flowing Darwin Glacier, draining the Antarctic Plateau through the Transantarctic Mountains into the Ross Sea. We are able to reconstruct DInSAR-derived vertical displacements to 7 mm mean absolute residual error and generally improve traditional tide-model output by up to 39 % from 10.8 to 6.7 cm RMSE against GPS data from areas where ice is in local hydrostatic equilibrium with the ocean and by up to 74 % from 21.4 to 5.6 cm RMSE against GPS data in feature-rich coastal areas where tide models have not been applicable before. Numerical modelling then reveals Young's modulus of E=1.0±0.56 GPa and an ice viscosity of ν=10±3.65 TPa s when finite-element simulations of tidal flexure are matched to 16 d of tiltmeter data, supporting the hypothesis that strain-dependent anisotropy may significantly decrease effective viscosity compared to isotropic polycrystalline ice on large spatial scales. Applications of our method include the following: refining coarsely gridded tide models to resolve small-scale features at the spatial resolution and vertical accuracy of SAR imagery, separating elastic and viscoelastic contributions in the satellite-derived flexure measurement, and gaining information about large-scale ice heterogeneity in Antarctic ice-shelf grounding zones, the missing key to improving current ice-sheet flow models. The reconstruction of the individual components forming DInSAR images has the potential to become a standard remote-sensing method in polar tide modelling. Unlocking the algorithm's full potential to answer multi-disciplinary research questions is desired and demands collaboration within the scientific community.
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Turney, Chris S. M. "Why didn't they ask Evans?: a response to Karen May." Polar Record 54, no. 2 (March 2018): 178–80. http://dx.doi.org/10.1017/s0032247418000220.
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In ’Why didn't they ask Evans?’ (Turney, 2017), I draw together previously unpublished sources and new analyses of published material to cast further light on the circumstances that led to the fatal events surrounding the return of Captain Robert Falcon Scott's Polar Party on the British Antarctic Expedition (BAE, 1911–1913). Of particular importance are the notes on the meeting between the Royal Geographical Society's President Lord Curzon and the widows Kathleen Scott and Oriana Wilson in April 1913, which explicitly identify Lieutenant Edward ‘Teddy’ Evans as having removed food that exceeded his allocation as a member of the Last Supporting Party (Curzon, 1913), the establishment and almost immediate closure of a ‘Committee of Enquiry’ chaired by Lord Curzon (Beaumont, 1913a, b, c; Cherry-Garrard, 1913a; Darwin, 1913; Goldie, 1913), the recognition of missing food at key depots by the returning Polar Party on the 7, 24 and 27 February 1912 (Scott, 1913a; Wilson, 1912), Evans’ anger at not being selected as a member of the Polar Party and his early departure home (Evans, 1912), the revised timeline of when Evans fell down with scurvy on the Ross Ice Shelf to apparently align with when and where the food was removed (The Advertiser, 3 April 1912, Adelaide: 10) (Cherry-Garrard, 1922; Ellis, 1969; Evans, 1912, 1913a, 1943; Lashly, 1912; Scott, 1913a, 1913b), Evans’ failure to ensure Scott's orders regarding the return of the dog sledging teams had been acted on (Cherry-Garrard, 1922; Gran, 1961; Hattersley-Smith & McGhie, 1984) and the misunderstanding amongst senior Royal Geographical Society members during Evans’ recuperation in the UK that Apsley Cherry-Garrard ‘was to meet the South Pole party, with two teams of dogs, at the foot of the [Beardmore] glacier’ (Markham, 1913). I would like to thank May (2018) for her comment and acknowledge that Edward Wilson's sketchbooks of the expedition's logistics, scientific priorities, sketches and notes on the BAE comprise entries from 1911–1912 and not solely from 1912, which Turney (2017) used to denote the year of the last entry.
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Bondarev, I. P., and L. V. Bondarenko. "Consorts of gastropod Rapana venosa (Valenciennes, 1846) in the Northern Black Sea. Part IV: Arthropoda." Marine Biological Journal 4, no. 2 (June 24, 2019): 11–22. http://dx.doi.org/10.21072/mbj.2019.04.2.02.
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This article containing information about study of the taxocene Arthropoda is a continuation of the cycle describing the composition of the consortium of the invasive gastropod mollusk Rapana venosa (Valenciennes, 1846). The consortium of R. venosa is still an unaccounted component in the biocenosis structure of the Black Sea shelf. The material used and the research methods are discussed in detail in previous articles of the cycle. The purpose of this work is to describe the complex of epibiontic organisms and to compile an annotated list of Arthropoda taxa of the consortium of R. venosa. The 27 species of phylum Arthropoda found in the consortium belong to two subphyla: Chelicerata (class Arachnida) and Crustacea (classes Malacostraca and Hexanauplia). The only representative of the arachnids class (Arachnida; Acari) – Rhombognathus notops (Gosse, 1855) – was found just twice (in a single specimen in samplings of 2016 and 2017). The shell of R. venosa serves as a substrate for the development of a variety of algae – favorable habitat for the epiphyton, which causes a high number and diversity of crustaceans in this biotope. The greatest taxonomic diversity was noted for the Malacostraca class – 25 species belonging to 22 genera of 19 families. Arthropods are represented in consortium of R. venosa by two main ecological groups – sedentary and mobile epibionts. The largest species diversity of Arthropoda is inherent in free-living mobile forms (23 species). Sedentary forms, which inferior in number of species (4), dominate by quantity (86 %) and biomass (94 %). The only representative of Cirripedia – Amphibalanus improvisus (Darwin, 1854) – is the most common (53 % of the total quantity) and massive crustacean, which contributes the most significant amount to the biomass (91.8 %) of Arthropoda in the consortium. More than 50 % of the Arthropoda species in the consortium are polyphages; phytophages are 20 %; detritophages are 28 % of the total number of arthropod species. The only adult specimen of fish ectoparasites is the isopod Elaphognathia bacescoi (Kussakin, 1969) found in a consortium of sandy rapa-whelk at a depth of 8 m in the Golubaya Bay of Sevastopol. All of the 27 species of Arthropoda found are present in the consortium of the sandy R. venosa, and only 3 species are noted on the rocky rapa-whelks. The differences in the composition of the consortium of the two ecomorphs of R. venosa are mainly due to the great development of the epiphytes and the reduced dynamics of the water masses in the sandy rapa-whelk habitats in Sevastopol region. Due to their taxonomic diversity, quantity and biomass, Arthropoda are an important element of the bottom biocenosis spatially and trophically associated with individuals of the largest gastropod of the Black Sea – R. venosa.
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Hiscock, Peter, and Philip Hughes. "Prehistoric and World War II Use of Shell Mounds in Darwin Harbour." Australian Archaeology 52, no. 1 (January 2001): 41–45. http://dx.doi.org/10.1080/03122417.2001.11681701.
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Darling, Marilyn S., and Karl M. Wilbur. "A Method for Measuring Growth in Living Barnacles (Crustacea: Cirripedia)." Journal of the Marine Biological Association of the United Kingdom 73, no. 3 (August 1993): 723–26. http://dx.doi.org/10.1017/s0025315400033257.
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A buoyant-weight method is described for the non-destructive estimation of fresh weight, total dry weight, shell weight and dry weight of organic matter in living barnacles Balanus amphitrite amphitrite Darwin. The method involves developing regression equations relating weight in air of these parameters to the buoyant weight of living barnacles in sea water. Buoyant weights of barnacles can then be used with the regression equations to obtain the weight in air of these consitituents, making possible the measurement of rates of shell growth and growth in dry weight without disturbance to the living animal. The method has been developed for the analysis of groups of juvenile barnacles cultured on coverslips, ranging in total dry weight from 1 to 60 mg, and for single mature individuals from 75 to 800 mg total dry weight. The buoyant-weight method has been used to measure shell growth of 2–3 mg d-1 in barnacles of 48 mg mean initial total dry weight cultured at 28°C.
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Sukparangsi, Woranop, Ashitapol Pochai, Chinnakit Wongkunanusorn, and Salinee Khachonpisitsak. "Discovery of Neonrosella vitiata (Darwin) and Newmanella spinosus Chan & Cheang (Balanomorpha, Tetraclitidae) from the Andaman Sea, eastern Indian Ocean." ZooKeys 833 (March 25, 2019): 1–20. http://dx.doi.org/10.3897/zookeys.833.30689.
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In this present study, distantly related acorn barnacle species in the subfamily Newmanellinae (Cirripedia, Thoracica, Tetraclitidae), including Neonrosellavitiata (Darwin, 1854) and Newmanellaspinosus Chan & Cheang, 2016, were discovered in the Andaman Sea of Thailand. Neo.vitiata can be readily distinguished from other newmanellids by shell plate and operculum morphology (external shell, tergum geometry, and pattern of parietal tube) and arthropodal characters (presence of basi-dorsal point at base of penis and triangular spines on cirri, setal type, and mouth parts). Both species were found to share overlapping territories on rocks at the rockweed zone, an area submerged under seawater most of the time throughout the year. This study highlights the first discovery of Neonrosella in the eastern Indian Ocean, whose ultrastructure compared to Newmanella is redescribed and illustrated here based on scanning electron microscopy.
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Brown, Michael. "Tiffany Watt Smith,On Flinching: Theatricality and Scientific Looking from Darwin to Shell Shock." Social History of Medicine 28, no. 3 (April 12, 2015): 649–51. http://dx.doi.org/10.1093/shm/hkv037.
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Garner, Stanton B. "On Flinching: Theatricality and Scientific Looking from Darwin to Shell Shock by Tiffany Watt Smith." Theatre Journal 67, no. 3 (2015): 575–76. http://dx.doi.org/10.1353/tj.2015.0077.
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Chan, Benny K. K., Yao Fong Tsao, and Monthon Ganmanee. "Morphological and molecular evidence support the intertidal barnacle Octomeris intermedia Nilsson-Cantell, 1921 (Thoracica, Chthamalidae) as a valid species in Indo-Pacific waters." ZooKeys 914 (February 20, 2020): 1–31. http://dx.doi.org/10.3897/zookeys.914.49328.
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Octomeris is a chthamalid intertidal barnacle with eight shell plates. There are currently two species of such barnacles: O. brunnea Darwin, 1854 (type locality in the Philippines), common in the Indo-Pacific region, and O. angulosa Sowerby, 1825, only recorded in South Africa. Octomeris intermedia Nilsson-Cantell, 1921, identified from the Mergui Archipelago in Myanmar, was considered to be conspecific with O. brunnea by Hiro (1939) based on samples collected in Taiwan. The morphological differences in shell and opercular plates between O. brunnea and O. intermedia are believed to be intra-specific variations due to different degrees of shell erosion. In the present study, the genetic and morphological differentiations of Octomeris in the Indo-Pacific region were examined. This study found two molecular clades (with inter-specific differences) based on the divergence in the COI genes, and the species also have distinct geographical distributions. The Octomeris brunnea clade covers samples collected from the Philippines and Taiwan waters and the other clade, which we argue is O. intermedia, is distributed in Phuket and Krabi, Thailand and Langkawi, Malaysia. Phuket and Krabi are located approximately 300 km south of the Mergui Archipelago, the type locality of O. intermedia. The morphology of samples collected from Thailand fits the type description of O. intermedia in Nilsson-Cantell (1921). Our study concludes that O. intermedia is a valid species based on morphological and molecular evidence.
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Tasch, Paul. "Geology and Zoology — A Symbiosis Darwin's Beagle Voyage and Galapagos Experience." Earth Sciences History 4, no. 2 (January 1, 1985): 98–112. http://dx.doi.org/10.17704/eshi.4.2.q635v04120qw08g7.
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Darwin's South American fossil collections yielded many insights. in one section he recorded the gradual vertical change in shell characteristics of fossil oysters. The giant fossil vertebrates brought the realization that several were precursors of living species. Contrary to accepted Catastrophism Theory, he inferred that all taxa found fossilized did not become extinct together since the living agouti, among others, had fossil precursors. He envisioned the way an existing molluscan fauna and its sedimentary matrix could be transformed into fossiliferous rocks reminiscent of the Tertiary, and also speculated about the kinds of fossils that the Galapagos biota would yield in some future rock column. Volcanic islands (Galapagos Archipelago and others) were linked in Darwin's thought to the appearance of "peculiar" taxa inhabiting these "mere spots" in the sea. Were these migrants from the nearest continents? If so, why were they so distinctive while carrying the imprint of their place of origin? If not, how did these four-legged and other terrestrial creatures get to the islands? Were the archipelagos ever united to the continents? Gradually Darwin was led to a continent-archipelago-continent concept. Continents were elevated archipelagos. (He had the Andean volcanoes in mind.) Archipelagos were submerged remnants of continents. He incorporated into this concept the rise and extinction of species: elevation of archipelagos were the "best nurseries" for appearance of new taxa, while subsidence of continents generally led to extinction of extant forms.
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Nurjannah, Alfiana, Darmanto Darmanto, and Ima Wijayanti. "Optimization Making Glucosamine Hydrochloride (HCl GlcN) of Crab Shell Waste through Chemical Hydrolysis." Jurnal Pengolahan Hasil Perikanan Indonesia 19, no. 1 (April 26, 2016): 26–35. http://dx.doi.org/10.17844/jphpi.2016.19.1.26.
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NAVARRO, J. L., K. A. GARCÍA, G. GONZÁLEZ, and M. B. MARTELLA. "The number of pores per area of eggshells is not always a reliable indicator of Rheidae species." Archaeofauna 29 (July 29, 2020): 185–92. http://dx.doi.org/10.15366/archaeofauna2020.29.012.
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From the end of the Pleistocene and up until the late Holocene, bones and abun- dant eggshell fragments testify to the hunting by the indigenous people of Rheidae in the Pampas and Chaco regions (greater rhea, Rhea americana), and in the Argentinian Patagonia (lesser/ Darwin´s rhea, R.pennata). The traditional method to set apart eggshell fragments from these two species consisted in counting the number pores on a given area to estimate their density. In this paper we evaluate the validity of this method with a new protocol to facilitate counting and assess its reliability on a large eggshell sample. As has been repeatedly proved, the greater rhea has a larger pore density than the lesser rhea. However, the variability of this density within each species, and even within the same egg, needs to be considered as this may lead to erroneous identification. More so when the number of pores per cm2 falls in the lowest range of the greater rhea or the highest range of the lesser rhea. In general, it is easier to misidentify a greater rheaeggshell fragment for that of the lesser rhea than the other way around. The possibility of misidentification also depends on the area of the shell that is being analyzed, since the original method did not apparently assess the density of pores in different areas of the same egg for each species. Although our results indicate that identification based on the original method is not as reliable as the one we propose here, a reappraisal of it with larger samples deriving from a larger specter of populations from both species would be recommendable.
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Ponciano, Luiza Corral Martins de Oliveira, Deusana Maria da Costa Machado, Ana Carolina Gelmini de Faria, Ana Carolina Maciel, Juliana Matos, and Mariana Novaes. "Hábitos de vida dos Gastropoda e Bellerophontida da formação Maecuru, Devoniano Médio, Bacia do Amazonas, Brasil." Anuário do Instituto de Geociências 30, no. 1 (January 1, 2007): 197–203. http://dx.doi.org/10.11137/2007_1_197-203.
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The Maecuru Formation comprises the Devonian-Carboniferous sedimentary sequence of Amazonas Basin and consists of fluvialdeltaics to neritics sandstones and pelites layers. Its fossiliferous sediments (the uppermost part of the Lontra Member) consists of hummocky cross-stratified fine-grained to very coarse sandstones beds.With the purpose of adding more information about the palaeoecology of The Maecuru Formation fossils, the life habits of gastropods and bellerophontids were inferred based on functional analysis and similarities with the living forms. The more significant features used were: (1) total frontal cross-sectional area, (2) height and relative positions of pressure point and center of gravity, (3) apertural margin morphology, (4) kind of symmetry and (5) surface smoothness. The species Platyceras (Orthonychia) steinmanni; Platyceras (Tumbophalus) hartti; Platyceras (Platyostoma) darwini; Platyceras (Platyostoma) (?) agassizi; Platyceras (Orthonychia) meerwarthi; Platyceras (Orthonychia) gracilis; Platyceras (Tumbophalus) coutoanus; "Platyceras" tschernischewi; "Platyceras" subconicum; "Platyceras" (Ortonychia) hussaki; "Platyceras" (Ortonychia) whitii; "Platyceras" (Ortonychia) whitii var. curua and "Platyceras" symmetricum var. maecuruensis represent the epifaunal gastropods with low mobility (coprophagous/suspension feeders) of the Maecuru Formation, living symbiotically directly over the anus of a crinoid or nearby. This coprophagous mode of life was probably a non-obligate relationship, because only the closest organisms will get all the advantages of using the crinoid host as a nutrient source. The others adult platyceratids would have a broader feeding repertoire, like as suspension feeders. The bellerophonts Plectonotus (Plectonotus) derbyi, Plectonotus (?) (Plectonotus) salteri e Bucanella reissi would have an epifaunal medium to high mobility, showing a predator habit preferably. On the other hand Bucania freitasi, Ptomatis forbesi and Bellerophon steltzneri showed morphologies compable to a grazer habit with medium mobility. This relative high diversity of gastropods and bellerophonts corroborates the environment of medium and inner shelf inferred for the Maecuru Formation among the others macrofossils, since the majority of Paleozoic fauna of gastropods were typically from shallow seas.
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Ray, Richard D., Kristine M. Larson, and Bruce J. Haines. "New determinations of tides on the north-western Ross Ice Shelf." Antarctic Science, October 14, 2020, 1–14. http://dx.doi.org/10.1017/s0954102020000498.
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Abstract New determinations of ocean tides are extracted from high-rate Global Positioning System (GPS) solutions at nine stations sitting on the Ross Ice Shelf. Five are multi-year time series. Three older time series are only 2–3 weeks long. These are not ideal, but they are still useful because they provide the only in situ tide observations in that sector of the ice shelf. The long tide-gauge observations from Scott Base and Cape Roberts are also reanalysed. They allow determination of some previously neglected tidal phenomena in this region, such as third-degree tides, and they provide context for analysis of the shorter datasets. The semidiurnal tides are small at all sites, yet M2 undergoes a clear seasonal cycle, which was first noted by Sir George Darwin while studying measurements from the Discovery expedition. Darwin saw a much larger modulation than we observe, and we consider possible explanations - instrumental or climatic - for this difference.
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"Essay Reviews - Charles Darwin: Imprimatur!" Notes and Records of the Royal Society of London 44, no. 1 (January 31, 1990): 125–31. http://dx.doi.org/10.1098/rsnr.1990.0010.
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Charles Darwin’s Beagle diary , ed. Richard Darwin Keynes. Cambridge University Press, 1988. Pp. xxix + 464. £35. ISBN 0-521-23503-0. Charles Darwin’s notebooks, 1836-1844 ed. Paul H. Barrett et al . Cambridge University Press, 1987. Pp. viii + 747. £65. ISBN 0-521-35055-7. A calendar of the correspondence of Charles Darwin, 1821-1882 , ed. Frederick Burkhardt & Sydney Smith. New York and London: Garland Publishing Inc., 1985. Pp. 690. £37.50. ISBN 0-521-35055-7. The correspondence of Charles Darwin , ed. Frederick Burkhardt & Sydney Smith. Cambridge: Cambridge University Press: Volume 1 (1821-1836), 1985. Pp. xxix + 702. £32.50. ISBN 0-521-25587-2; Volume 2 (1837-1843), 1986. Pp. xxv + 603. £32.50. ISBN 0-521-25588-0; Volume 3 (1844-1846), 1987. Pp. xxxii + 523. £32.50. ISBN 0-521-25589-9. Darwin scholars have long had access to a substantial body of his correspondence in print, thanks to the three-volume Life and letters and the two-volume More letters edited by his son Francis. Letters between Darwin and John Henslow were published by Nora Barlow, who also edited the Beagle notebooks and diary. A more intense interest in the discovery and publication of the theory of natural selection began in the 1960s, following the consolidation of the modern synthesis with genetics. In the early decades of this century Darwinism still had substantial rivals as a scientific theory. Darwin himself was perceived as the man who had ‘started the ball rolling’ in the establishment of scientific evolutionism, but not necessarily as the founder of the dominant theory of the evolutionary mechanism. But once the modern synthesis of Darwinism and genetics was firmly established, its proponents began to see the original creation of the selection theory as the main event in the history of evolutionism. Sir Gavin De Beer and Sydney Smith began a renewed effort to collect and publish Darwin’s private papers. Historians of science were encouraged to investigate the treasure-trove that began to accumulate at Cambridge University Library. The books reviewed here represent the latest thrust toward the publication of Darwin material, a thrust that may well end with virtually everything that survives being available on the library shelf.
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CASTILLA, JUAN CARLOS. "Darwin taxonomist: Barnacles and shell burrowing barnacles." Revista chilena de historia natural 82, no. 4 (December 2009). http://dx.doi.org/10.4067/s0716-078x2009000400002.
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