scholarly journals The Coral of Plants

2020 ◽  
Vol 89 (3) ◽  
Author(s):  
János Podani

The present article has two primary objectives. First, the article provides a historical overview of graphical tools used in the past centuries for summarizing the classification and phylogeny of plants. It is emphasized that each published diagram focuses on only a single or a few aspects of the present and past of plant life on Earth. Therefore, these diagrams are less useful for communicating general knowledge in botanical research and education. Second, the article offers a solution by describing the principles and methods of constructing a lesser- known image type, the coral, whose potential usefulness in phylogenetics was first raised by Charles Darwin. Cladogram topology, phylogenetic classification and nomenclature, diversity of taxonomic groups, geological timescale, paleontological records, and other relevant information on the evolution of Archaeplastida are simultaneously condensed for the first time into the same figure – the Coral of Plants. This image is shown in two differently scaled parts to efficiently visualize as many details as possible, because the evolutionary timescale is much longer, and the extant diversity is much lower for red and green algae than for embryophytes. A fundamental property of coral diagrams, that is their self-similarity, allows for the redrawing of any part of the diagram at smaller scales.

Author(s):  
David Reznick ◽  
Joseph Travis

When Charles Darwin and Alfred Russell Wallace proposed their theory of evolution by natural selection, the concepts of evolution and speciation were not new. Darwin introduced The Origin with “An Historical Sketch,” in which he summarized the work of 34 previous authors who had speculated on evolution and the origin of species. What was new about Darwin and Wallace’s proposition was natural selection as the mechanism of evolutionary change. Darwin further proposed that natural selection was a unifying process that accounts for adaptation, for speciation, and hence for the diversity of life on earth. Darwin and Wallace proposed natural selection as a process that caused evolution. Adaptations are features of organisms that were shaped by this process. The modern version of Darwin and Wallace’s theory allows for other agents of evolution, such as genetic drift, migration, and mutation, but adaptation remains a product of natural selection alone. The virtue of their proposal is that it allows us to develop testable hypotheses about cause-and-effect relationships between features of the environment and presumed adaptations. Natural selection immediately became a source of controversy, although the nature of the controversy has shifted over time. First, there has been considerable debate about the definition of adaptation (e.g., Reeve and Sherman 1993). We do not wish to add to or summarize this debate because we feel that Darwin got it right the first time. Besides defining a cause-and-effect relationship between selection and adaptation, Darwin emphasized that we should not expect organisms to be perfectly adapted to their environment. In fact, this emphasis was a large component of his argument against divine creation. For example, Darwin recognized, through his experience with artificial selection, that different aspects of morphology were in some way “tied” to one another so that selection on one trait would cause correlated changes in others that were not necessarily adaptive. He also recognized that organisms were subject to constraints that might limit their ability to adapt. Finally, he argued that how organisms evolved was a function of their history, so that the response to selection on the same trait would vary among lineages. A more telling criticism considers the application of cause-and-effect reasoning to the interpretation of features of organisms as adaptations, and hence to the empirical study of adaptation.


2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.


Author(s):  
Rachel Ablow

The nineteenth century introduced developments in science and medicine that made the eradication of pain conceivable for the first time. This new understanding of pain brought with it a complex set of moral and philosophical dilemmas. If pain serves no obvious purpose, how do we reconcile its existence with a well-ordered universe? Examining how writers of the day engaged with such questions, this book offers a compelling new literary and philosophical history of modern pain. The book provides close readings of novelists Charlotte Brontë and Thomas Hardy and political and natural philosophers John Stuart Mill, Harriet Martineau, and Charles Darwin, as well as a variety of medical, scientific, and popular writers of the Victorian age. The book explores how discussions of pain served as investigations into the status of persons and the nature and parameters of social life. No longer conceivable as divine trial or punishment, pain in the nineteenth century came to seem instead like a historical accident suggesting little or nothing about the individual who suffers. A landmark study of Victorian literature and the history of pain, the book shows how these writers came to see pain as a social as well as a personal problem. Rather than simply self-evident to the sufferer and unknowable to anyone else, pain was also understood to be produced between persons—and even, perhaps, by the fictions they read.


2021 ◽  
Vol 7 (1) ◽  
pp. eabd8180
Author(s):  
Orlando B. Giorgetti ◽  
Prashant Shingate ◽  
Connor P. O’Meara ◽  
Vydianathan Ravi ◽  
Nisha E. Pillai ◽  
...  

The rules underlying the structure of antigen receptor repertoires are not yet fully defined, despite their enormous importance for the understanding of adaptive immunity. With current technology, the large antigen receptor repertoires of mice and humans cannot be comprehensively studied. To circumvent the problems associated with incomplete sampling, we have studied the immunogenetic features of one of the smallest known vertebrates, the cyprinid fish Paedocypris sp. “Singkep” (“minifish”). Despite its small size, minifish has the key genetic facilities characterizing the principal vertebrate lymphocyte lineages. As described for mammals, the frequency distributions of immunoglobulin and T cell receptor clonotypes exhibit the features of fractal systems, demonstrating that self-similarity is a fundamental property of antigen receptor repertoires of vertebrates, irrespective of body size. Hence, minifish achieve immunocompetence via a few thousand lymphocytes organized in robust scale-free networks, thereby ensuring immune reactivity even when cells are lost or clone sizes fluctuate during immune responses.


Author(s):  
Allison Ragan ◽  
Tessa Sommer ◽  
Frank Drews

This study examined the effect of humor on airline safety information retention. Passenger attention to pre- flight safety demonstrations is low, even though it may impact the chance of survival in an aviation accident. Airlines have employed humor and entertainment to educate passengers on safety information. This study explored whether the humorous presentation increases retention of safety information, or if humor acts as a distraction from safety relevant information. Participants viewed two pre-flight safety demonstration videos (humorous and non-humorous) in counterbalanced order then answered short-answer questions about the content of the videos. Retention scores after viewing either type of video for the first time were the same. However, when a humorous video was shown prior to a standard safety video, retention scores for safety material dropped. These findings suggest that humorous safety demonstrations may be more effective, not because they are best at conveying information, but because passengers do not attend to standard videos if they have previously been exposed to a humorous version.


2014 ◽  
Vol 11 (S308) ◽  
pp. 542-545 ◽  
Author(s):  
S. Nadathur ◽  
S. Hotchkiss ◽  
J. M. Diego ◽  
I. T. Iliev ◽  
S. Gottlöber ◽  
...  

AbstractWe discuss the universality and self-similarity of void density profiles, for voids in realistic mock luminous red galaxy (LRG) catalogues from the Jubilee simulation, as well as in void catalogues constructed from the SDSS LRG and Main Galaxy samples. Voids are identified using a modified version of the ZOBOV watershed transform algorithm, with additional selection cuts. We find that voids in simulation areself-similar, meaning that their average rescaled profile does not depend on the void size, or – within the range of the simulated catalogue – on the redshift. Comparison of the profiles obtained from simulated and real voids shows an excellent match. The profiles of real voids also show auniversalbehaviour over a wide range of galaxy luminosities, number densities and redshifts. This points to a fundamental property of the voids found by the watershed algorithm, which can be exploited in future studies of voids.


Paleobiology ◽  
2018 ◽  
Vol 44 (1) ◽  
pp. 40-57 ◽  
Author(s):  
Emily G. Mitchell ◽  
Nicholas J. Butterfield

AbstractBedding-plane assemblages of Ediacaran fossils from Mistaken Point, Newfoundland, are among the oldest known records of complex multicellular life on Earth (dated to ~565 Ma). The in situ preservation of these sessile but otherwise deeply enigmatic organisms means that statistical analyses of specimen positions can be used to illuminate their underlying ecological dynamics, including the interactions between taxa.Fossil assemblages on Mistaken Point D and E surfaces were mapped to millimeter accuracy using differentiated GPS. Spatial correlations between 10 well-defined taxa (Bradgatia, Charniid,Charniodiscus,Fractofusus, Ivesheadiomorphs, Lobate Discs,Pectinifrons,Plumeropriscum,Hiemalora, andThectardis) were identified using Bayesian network inference (BNI), and then described and analyzed using spatial point-process analysis. BNI found that the E-surface community had a complex web of interactions and associations between taxa, with all but one taxon (Thectardis) interacting with at least one other. The unique spatial distribution ofThectardissupports previous, morphology-based arguments for its fundamentally distinct nature. BNI revealed that the D-surface community showed no interspecific interactions or associations, a pattern consistent with a homogeneous environment.On the E surface, all six of the abundant taxonomic groups (Fractofusus,Bradgatia, Charniid,Charniodiscus,Thectardis, andPlumeropriscum) were found to have a unique set of interactions with other taxa, reflecting a broad range of underlying ecological responses. Four instances of habitat associations were detected between taxa, of which two (Charniodiscus–PlumeropriscumandPlumeropriscum–Fractofusus) led to weak competition for resources. One case of preemptive competition between Charniid and Lobate Discs was detected. There were no instances of interspecific facilitation. Ivesheadiomorph interactions mirror those ofFractofususandCharniodiscus, identifying them as a form-taxonomic grouping of degradationally homogenized taphomorphs. The absence of increased fossil abundance in proximity to these taphomorphs argues against scavenging or saprophytic behaviors dominating the E-surface community.


Insects ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 324 ◽  
Author(s):  
Karin Kirchgatter ◽  
Lilian de Oliveira Guimarães ◽  
Henrry Hugo Yañez Trujillano ◽  
Fernando Rafael Arias ◽  
Abraham Cáceres ◽  
...  

Identification of mosquito species is necessary for determining the entomological components of malaria transmission, but it can be difficult in morphologically similar species. DNA sequences are largely used as an additional tool for species recognition, including those that belong to species complexes. Kerteszia mosquitoes are vectors of human and simian malaria in the Neotropical Region, but there are few DNA sequences of Kerteszia species in public databases. In order to provide relevant information about diversity and improve knowledge in taxonomy of Kerteszia species in Peru, we sequenced part of the mitochondrial genome, including the cytochrome c oxidase I (COI) barcode region. Phylogenetic analyses structured all species of mosquitoes collected in Peru into a single clade, separate from the Brazilian species. The Peruvian clade was composed of two lineages, encompassing sequences from Anopheles (Kerteszia) boliviensis and Anopheles (Kerteszia) pholidotus. An. pholidotus sequences were recorded for the first time in Peru, whereas An. boliviensis sequences were for the first time published in the GenBank database. Sequences generated from specimens morphologically identified as Anopheles (Kerteszia) cruzii clustered into three separate clades according to the collection localities of Serra do Mar, Serra da Mantiqueira, and Serra da Cantareira, confirming An. cruzii as a species complex, composed of at least three putative species.


2019 ◽  
Vol 22 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Rebekah D. Wallace ◽  
Charles T. Bargeron ◽  
Jamie K. Reaser

AbstractThe issue of how to detect and rapidly respond to invasive species before it is economically infeasible to control them is one of urgency and importance at international, national, and subnational scales. Barriers to sharing invasive species data—whether in the form of policy, culture, technology, or operational logistics—need to be addressed and overcome at all levels. We propose guiding principles for following standards, formats, and protocols to improve information sharing among US invasive species information systems and conclude that existing invasive species information standards are adequate for the facilitation of data sharing among all sectors. Rather than creating a single information-sharing system, there is a need to promote interfaces among existing information systems that will enable them to become inter-operable, to foster simultaneous access, and to deliver any and all relevant information to a particular user or application in a seamless fashion. The actions we propose include implementing a national campaign to mobilize invasive species occurrence data into publicly available information systems; maintaining a current list of invasive species data integrators/clearinghouses; establishing an agreement for sharing data among the primary US invasive species information systems; enhancing the Integrated Taxonomic Information System to fully cover taxonomic groups not yet complete; further developing and hosting data standards for critical aspects of invasive species biology; supporting and maintaining the North American Invasive Species Management Association’s mapping standards; identifying standard metrics for capturing the environmental and socio-economic impact of invasive species, including impacts and management options; continuing to support US engagement in international invasive species data sharing platforms; and continuing US membership in the Global Biodiversity Information Facility.


Antiquity ◽  
2009 ◽  
Vol 83 (320) ◽  
pp. 458-461
Author(s):  
Christopher Evans

AbstractWe are grateful to Chris Evans for convening and introducing this imaginative archaeological tribute to the work of Charles Darwin, 150 years after the publication of his On the origin of species – the inspiration for an evolutionary concept of history in so many fields. June 2009 is also the 150th anniversary of a yet more momentous event in the history of archaeology, the endorsement of the antiquity of human tool-making by observations in the Somme gravels. Clive Gamble and Robert Kruszynski reconstruct the occasion and publish the famous axe for the first time. Chris Evans returns to present us with the bitter-sweet spectacle of the Darwin family as excavators and Tim Murray rediscovers a suite of pictures made for John Lubbock which show how prehistoric life was envisaged in polite society at the time. Lastly we are grateful to Colin Renfrew for his own reflections on the anniversary.


Sign in / Sign up

Export Citation Format

Share Document