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Innovation and elaboration on the avian tree of life
No full textWidely documented, megaevolutionary jumps in phenotypic diversity continue to perplex researchers because it remains unclear whether these marked changes can emerge from microevolutionary processes. Here, we tackle this question using new approaches for modeling multivariate traits to evaluate the magnitude and distribution of elaboration and innovation in the evolution of bird beaks. We find that elaboration, evolution along the major axis of phenotypic change, is common at both macro- and megaevolutionary scales, whereas innovation, evolution away from the major axis of phenotypic change, is more prominent at megaevolutionary scales. The major axis of phenotypic change among species beak shapes at megaevolutionary scales is an emergent property of innovation across clades. Our analyses suggest that the reorientation of phenotypes via innovation is a ubiquitous route for divergence that can arise through gradual change alone, opening up further avenues for evolution to explore.Copyright© 2023 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY). The linked document is the published version of the article.NHM Repositor
Metaphycus macadamiae (Hymenoptera: Encyrtidae) – a biological control agent of macadamia felted coccid Acanthococcus ironsidei (Hemiptera: Eriococcidae) in Hawaii
Get PDFA new species of encyrtid wasp, Metaphycus macadamiae Polaszek & Noyes sp. n., (Hymenoptera: Encyrtidae: Encyrtinae) is described as a solitary endoparasitoid of the invasive macadamia felted coccid, Acanthococcus ironsidei (Hemiptera: Eriococcidae) in Hawaii. This parasitoid is native to Australia, and the species description is based on material collected from a Macadamia integrifolia Maiden & Betche (Proteaceae) plantation in New South Wales, Australia, the native region of the host tree and insect. It is described here because it is a potential biological control agent against this pest where it has recently invaded Hawaii and South Africa.Copyright: © 2020 Polaszek et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article.NHM Repositor
Revisions to the Eocene carpoflora of Anjou, western France, with new data from X-ray tomography
Get PDFSelected fruits and seeds preserved as molds and casts in sediments from the Anjou flora of Maine-et-Loire have been reexamined with the aid of X-ray tomography. Virtual casts and surface renderings from micro-CT scanning data reveal external and internal morphological characters that were not visible by standard reflected light microscopy. Application of this methodology leads to a revision of the fruit formerly treated as Juglandicarya. It is a 5-valved capsule of likely sapindalean affnity, and is placed in Vaudoisia gruetii (Vaudois-Miéja) gen. et. comb. nov. A seed with the characteristic rumination of Anonaspermum is also recognized for the #rst time, as are capsular fruits of Ericaceae. We note that many disseminules are hidden from optical viewing because they are buried within the hand samples. A more extensive micro-CT scan investigation of more samples, including those showing only fossil leaf impressions at the surface, may be expected to yield a wealth of
new information on this classic flora.Copyright © 2022 Société botanique de France. The attached document is the published version of the article.NHM Repositor
The venom and telopodal defence systems of the centipede Lithobius forficatus are functionally convergent serial homologues
Get PDFAbstract
Background
Evolution of novelty is a central theme in evolutionary biology, yet studying the origins of traits with an apparently discontinuous origin remains a major challenge. Venom systems are a well-suited model for the study of this phenomenon because they capture several aspects of novelty across multiple levels of biological complexity. However, while there is some knowledge on the evolution of individual toxins, not much is known about the evolution of venom systems as a whole. One way of shedding light on the evolution of new traits is to investigate less specialised serial homologues, i.e. repeated traits in an organism that share a developmental origin. This approach can be particularly informative in animals with repetitive body segments, such as centipedes.
Results
Here, we investigate morphological and biochemical aspects of the defensive telopodal glandular organs borne on the posterior legs of venomous stone centipedes (Lithobiomorpha), using a multimethod approach, including behavioural observations, comparative morphology, proteomics, comparative transcriptomics and molecular phylogenetics. We show that the anterior venom system and posterior telopodal defence system are functionally convergent serial homologues, where one (telopodal defence) represents a model for the putative early evolutionary state of the other (venom). Venom glands and telopodal glandular organs appear to have evolved from the same type of epidermal gland (four-cell recto-canal type) and while the telopodal defensive secretion shares a great degree of compositional overlap with centipede venoms in general, these similarities arose predominantly through convergent recruitment of distantly related toxin-like components. Both systems are composed of elements predisposed to functional innovation across levels of biological complexity that range from proteins to glands, demonstrating clear parallels between molecular and morphological traits in the properties that facilitate the evolution of novelty.
Conclusions
The evolution of the lithobiomorph telopodal defence system provides indirect empirical support for the plausibility of the hypothesised evolutionary origin of the centipede venom system, which occurred through functional innovation and gradual specialisation of existing epidermal glands. Our results thus exemplify how continuous transformation and functional innovation can drive the apparent discontinuous emergence of novelties on higher levels of biological complexity.Copyright © The Author(s) 2024. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data. The attached file is the published version of the article.NHM Repositor
The contributions to bryozoology of J.W. Gregory (1864–1932)
Get PDFThe attached file is the published version of the article.NHM Repositor
Fossil micrometeorites from Monte dei Corvi: Searching for dust from the Veritas asteroid family and the utility of micrometeorites as a palaeoclimate proxy
No full textWe searched late Miocene sedimentary rocks in an attempt to recover fossil micrometeorites derived from the Veritas asteroid family. This study was motivated by the previous identification of a pronounced 3He peak (4-5x above background) within marine sediments with ages between ∼8.5–6.9 Ma ago (Montanari et al., 2017. GSA Bulletin, 129:1357–1376). We processed 118.9 kg of sediment from the Monte dei Corvi beach section (Italy), the global type-section for the Tortonian epoch (11.6–7.2 Ma). Samples were collected both before and within the 3He peak. Although a small number of iron-rich (I-type) fossil micrometeorites were recovered from each horizon studied (Ntotal = 20), there is no clear difference between the pre- and intra- 3He peak samples. All micrometeorites are compositionally similar, and three out of five horizons yielded similar abundances and particle sizes. Micrometeorites extracted from sediments at the base of the 3He peak were exclusively small (ø <75 µm), while micrometeorites extracted from sediments near the highest 3He values were relatively large (ø <270 µm). The recovered fossil micrometeorites are interpreted as samples of the background dust flux derived from metal-bearing chondritic asteroids. The presence of a 3He signature combined with the absence of fossil micrometeorites or extraterrestrial spinels (Boschi et al., 2019, Spec. Pap. Geol. Soc. Am. 542:383–391) unambiguously related to the Veritas event suggests that the Veritas family is composed of highly friable materials that rarely survive on the sea floor to become preserved in the geological record. Our data supports the existing hypothesis that the Veritas asteroid family is an aqueously altered carbonaceous chondrite parent body, one that contains minimal native metal grains or refractory Cr-spinels. The low yield of fossil micrometeorites at Monte dei Corvi is attributed to loss of particles by dissolution whilst they resided on the sea floor but also due to high sedimentation rates leading to dilution of the extraterrestrial dust flux at this site. As with other fossil micrometeorite collections (e.g. Cretaceous chalk [Suttle and Genge, EPSL, 476:132–142]) the I-type spherules have been altered since deposition. In most particles, both magnetite and wüstite remain intact but have been affected by solid state geochemical exchange, characterised by partial leaching of Ni, Co and Cr and implantation of Mn, Mg, Si and Al. In some particles Mn concentrations reach up to 16.6 wt%. Conversely, in some micrometeorites wüstite has been partially dissolved, or even replaced by calcite or ankerite. Finally, we observe evidence for wüstite recrystallisation, forming a second generation of magnetite. This process is suggested to occur by oxidation during residence on the seafloor and has implications for the use of fossil I-type micrometeorites as a potential proxy for probing Earth’s upper atmospheric composition (oxidative capacity) in the geological past. However, solutions to the limitations of post-depositional recrystallisation are suggested. Fossil I-type spherules remain a potential tool for palaeo-climatic studies.Copyright©2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). The linked file is the published version of the article.NHM Repositor
Alteration conditions on the CM and CV parent bodies – Insights from hydrothermal experiments with the CO chondrite Kainsaz
No full textThis study simulates the hydrothermal conditions that existed on carbonaceous chondrite planetesimals in the early solar system. Our experiments are relevant to alteration conditions that existed on the CV parent body and the late stage oxidizing alteration of the CM chondrites. We conducted 11 alteration experiments using chips of the CO3 chondrite Kainsaz. Water was added to each chip and sealed in separate Teflon reaction vessels for 175 days. Samples were altered at different initial water-to-rock ratios (W/R: 0.2–0.8) and temperatures (50 °C and 150 °C). Isotopically doped 17O-rich heavy water (δ17O: +64.5‰) was used in five runs. All samples experienced pronounced alteration under a partially open system environment where gases were able to escape the reaction vessels.
The style of alteration (Fe-alkali metasomatism) is similar in all cases. The principal alteration minerals formed are Fe-oxyhydroxides (goethite) and Fe-oxides (magnetite), with smaller quantities of Fe-sulphides. Minor phases formed include fayalite, sulphates (gypsum and Fe-sulphate) and calcite. Nanophase, poorly crystalline phyllosilicates formed in the high-temperature samples but are absent from the low-temperature experiments. In all instances, Mg-rich chondrule silicates remained chemically unaltered although some grains suffered hydrothermal fracture. Chondrule mesostases remained largely unaffected. By contrast, kamacite readily dissolved, acting as a source of Fe and Ni for the fluid phase. A new generation of nanophase Fe-sulphides formed within the matrix, while pre-existing pyrrhotite group sulphides experienced Ni enrichment ( 10 at%) were formed in the 150 °C samples, most likely by sulphidation of taenite.
Matrix alteration cemented grains together, reducing porosity. The fine-grained matrix shows highly variable degrees of alteration, with minimally altered matrix in direct contact with regions of heavily altered matrix. Chondrule fine-grained rims (FGRs) were preferentially altered. These textures imply that the unaltered matrix readily reacted with the fluid phase, resulting in an efficient depletion of dissolved ions (Fe2+ and S2-), limiting reactivity until further primary phases were dissolved. At larger length-scales the distribution of heavily altered matrix reveals the presence of large ∼100 µm wide channels that meander through the specimens. Their textures resemble features seen in some CM chondrites and the ungrouped CO-like chondrite MIL 07687. We suggest that alteration fronts developed by sustained rapid reaction of matrix with dissolved cations in solution. Our observations provide a mechanism for the establishment and maintenance of geochemical microenvironments on chondritic asteroids. The effects of open system loss notwithstanding, our experiments demonstrate that more advanced alteration is correlated with higher initial W/R ratios.
The use of 17O-rich doped water allowed the isotopic effects of aqueous alteration to be observed. Bulk rock compositions evolved towards the initial water composition, reflecting the incorporation of heavy O into hydrated minerals. Additionally, altered samples shifted in δ18O space, reflecting the competing effects of water–mineral fractionation and mass fractionation due to the preferential escape of isotopically light water.https://creativecommons.org/licenses/by/4.0/deed.enCopyright / 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). The linked file is the published version of the article.NHM Repositor
Amplicon Sequencing of Variable 16S rRNA from Bacteria and ITS2 Regions from Fungi and Plants, Reveals Honeybee Susceptibility to Diseases Results from Their Forage Availability under Anthropogenic Landscapes
Get PDFEuropean Apis mellifera and Asian Apis cerana honeybees are essential crop pollinators. Microbiome studies can provide complex information on health and fitness of these insects in relation to environmental changes, and plant availability. Amplicon sequencing of variable regions of the 16S rRNA from bacteria and the internally transcribed spacer (ITS) regions from fungi and plants allow identification of the metabiome. These methods provide a tool for monitoring otherwise uncultured microbes isolated from the gut of the honeybees. They also help monitor the composition of the gut fungi and, intriguingly, pollen collected by the insect. Here, we present data from amplicon sequencing of the 16S rRNA from bacteria and ITS2 regions from fungi and plants derived from honeybees collected at various time points from anthropogenic landscapes such as urban areas in Poland, UK, Spain, Greece, and Thailand. We have analysed microbial content of honeybee intestine as well as fungi and pollens. Furthermore, isolated DNA was used as the template for screening pathogens: Nosema apis, N. ceranae, N. bombi, tracheal mite (Acarapis woodi), any organism in the parasitic order Trypanosomatida, including Crithidia spp. (i.e., Crithidia mellificae), neogregarines including Mattesia and Apicystis spp. (i.e., Apicistis bombi). We conclude that differences between samples were mainly influenced by the bacteria, plant pollen and fungi, respectively. Moreover, honeybees feeding on a sugar based diet were more prone to fungal pathogens (Nosema ceranae) and neogregarines. In most samples Nosema sp. and neogregarines parasitized the host bee at the same time. A higher load of fungi, and bacteria groups such as Firmicutes (Lactobacillus); γ-proteobacteria, Neisseriaceae, and other unidentified bacteria was observed for Nosema ceranae and neogregarine infected honeybees. Healthy honeybees had a higher load of plant pollen, and bacteria groups such as: Orbales, Gilliamella, Snodgrassella, and Enterobacteriaceae. Finally, the period when honeybees switch to the winter generation (longer-lived forager honeybees) is the most sensitive to diet perturbations, and hence pathogen attack, for the whole beekeeping season. It is possible that evolutionary adaptation of bees fails to benefit them in the modern anthropomorphised environment.Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). The attached file is the published version of the article.NHM Repositor
Quantitative ichnology: a novel framework to determine the producers of locomotory trace fossils with the ichnogenus Gordia as a case study
No full textAbstract: Trace fossils record the interactions between organisms and their surroundings, and can therefore provide unique insights into the coevolution of trace makers and the environment. However, identifying the producers of trace fossils is challenging because different animals can create very similar traces and many ichnotaxa can therefore only be attributed to broad morphological grades. For example, simple horizontal traces like Gordia are generally suggested to have been produced by vermiform organisms, potentially encompassing a range of animal phyla. This uncertainty makes it difficult to decipher their palaeobiological significance through major evolutionary events and episodes of environmental change. We have developed new mathematical approaches for identifying previously unrecognized signatures left by the trace makers of simple marine locomotory traces. We calculated the deviation angle series of self‐crossing traces made by extant isopods, polychaetes, gastropods and nematodes, computing the frequency spectrum and autocorrelation function in each case. The results reveal that each of these taxa left unique markers during the trace‐making process, reflecting differences in their anatomy and locomotory behaviour. We were able to identify the possible trace makers of several early Palaeozoic Gordia specimens, demonstrating that ichnospecies within the same ichnogenus can be created by distantly related animals with very different morphologies and/or behaviours. This novel mathematical framework has great potential for identifying the possible producers of diverse trace fossils through deep time, helping to uncover the earliest evidence of certain animals or behaviours. It also has great potential for quantifying ichnotaxonomy, consolidating the link between ichnology and palaeobiology.Copyright © 2023 The Authors. Palaeontology published by John Wiley & Sons Ltd on behalf of The Palaeontological Association
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. The linked file is the published version of the article.NHM Repositor
Petrography, geochemistry and mineralogy of the Stonehenge Sarsens: Digital data collection
No full textThis collection includes a suite of digital materials that, in combination, characterise the petrography, mineralogy and geochemistry of a sarsen upright (Stone 58) from the central trilithon horseshoe at Stonehenge. The collection arises from work undertaken during the British Academy/Leverhulme Trust project “Geochemical fingerprinting the sarsen stones at Stonehenge” (Small Research Grant SG-170610), led by the University of Brighton.
As part of the project, permission was granted by English Heritage to sample a section from one of three cores drilled through the full thickness of Stone 58 during conservation work in 1958. This core had been returned to the UK from Florida in 2018 by Mr Robert Phillips, an employee of Van Moppes (Diamond Tools) Ltd, Basingstoke, who had been at Stonehenge during the drilling work. Mr Phillips was granted permission by the Ministry of Works to retain the core on behalf of the company and was gifted it by Van Moppes on his retirement to the USA. This core – referred to as the Phillips’ Core – is now held in the English Heritage Collections Store at Temple Cloud (Bath, UK).
The Phillips’ Core is 108cm long, has a 2.5cm diameter and is broken into six pieces ranging in length from 7 to 29cm. The digital materials within this collection result from the analysis of section 2-3 of the core, from 29 to 36cm along its length. Full details of sampling, analytical approaches and interpretation are provided in Nash et al. (2021) (see Metadata).Data copyright © David Nash, Jake Ciborowski, Tobias Salge, Magret Damaschke, Steven Goderis unless otherwise stated This work is licensed under a Creative Commons Attribution 4.0 International License. The linked data page is the published version of the data.NHM Repositor