Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

2012 ◽  
Vol 39 (2) ◽  
pp. 217-233 ◽  
Author(s):  
J. David Archibald
Keyword(s):  
Fossil Record ◽  
Evolutionary Biology ◽  
Phylogenetic Trees ◽  
Charles Darwin ◽  
The Other ◽  
Charles Lyell ◽  
Single Origin ◽  
Molecular Studies ◽  
Richard Owen ◽  
First Time

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.

Plant-Herbivore Interactions

2001 ◽  
Author(s):  
May Berenbaum
Keyword(s):  
Evolutionary Biology ◽  
Charles Darwin ◽  
Evolutionary Change ◽  
The Other ◽  
Origin Of Species ◽  
Interacting Species ◽  
Single Host ◽  
External Conditions ◽  
Clear Insight ◽  
Plant Herbivore

As is the case with most supposedly modern concepts in evolutionary biology, the idea of coevolution, or reciprocal evolutionary change between interacting species, actually goes back to Charles Darwin. In the introduction to The Origin of Species (1859), he wrote: …In considering the Origin of Species, it is quite conceivable that a naturalist, reflecting on the mutual affinities of organic beings, on their embryological relations, their geographical distribution, geological succession, and other such facts, might come to the conclusion that species had not been independently created, but had descended, like varieties, from other species. Nevertheless, such a conclusion, even if wellfounded, would be unsatisfactory, until it could be shown how the innumerable species inhabiting this world have been modified, so as to acquire that perfection of structure and coadaptation which justly excites our admiration. It is, therefore, of the highest importance to gain a clear insight into the means of modification and coadaptation…. Early on, then, Darwin pointed out the importance of interactions among organisms in determining evolutionary change, as opposed to “external conditions such as climate, food,” or even “the volition” of the organism itself. Interactions among organisms, however, take many forms. Antagonistic interactions, in which one species benefits and the other is harmed, are themselves diverse. Among those interactions in which both species are animals, the gamut runs from predation, in which one species kills and consumes several individuals of the other species during its lifetime, to parasitism, in which one species merely saps the “reserves” and rarely kills its host. Intermediate and unique to the phylum Arthropoda is parasitoidism, in which one species kills its prey, as does a predator, but, like a parasite, is normally restricted to a single host individual. A comparable continuum exists for interactions between an animal and a plant species; these associations are usually referred to as forms of herbivory (with parasitoidism akin to internal seed feeders of plants). In mutualistic interactions, both species benefit from the interaction. Mutualisms can involve interactions between animals and plants, generally in which a food reward from the plant is exchanged for mobility provided by the animal partner.

scholarly journals Phylogenomic resolution of scorpions reveals multilevel discordance with morphological phylogenetic signal

2015 ◽  
Vol 282 (1804) ◽  
pp. 20142953 ◽  
Author(s):  
Prashant P. Sharma ◽  
Rosa Fernández ◽  
Lauren A. Esposito ◽  
Edmundo González-Santillán ◽  
Lionel Monod
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Digestive System ◽  
Sequence Data ◽  
Phylogenetic Signal ◽  
Molecular Sequence Data ◽  
Molecular Sequence ◽  
Single Origin ◽  
As Species ◽  
First Time

Scorpions represent an iconic lineage of arthropods, historically renowned for their unique bauplan, ancient fossil record and venom potency. Yet, higher level relationships of scorpions, based exclusively on morphology, remain virtually untested, and no multilocus molecular phylogeny has been deployed heretofore towards assessing the basal tree topology. We applied a phylogenomic assessment to resolve scorpion phylogeny, for the first time, to our knowledge, sampling extensive molecular sequence data from all superfamilies and examining basal relationships with up to 5025 genes. Analyses of supermatrices as well as species tree approaches converged upon a robust basal topology of scorpions that is entirely at odds with traditional systematics and controverts previous understanding of scorpion evolutionary history. All analyses unanimously support a single origin of katoikogenic development, a form of parental investment wherein embryos are nurtured by direct connections to the parent's digestive system. Based on the phylogeny obtained herein, we propose the following systematic emendations: Caraboctonidae is transferred to Chactoidea new superfamilial assignment ; superfamily Bothriuroidea revalidated is resurrected and Bothriuridae transferred therein; and Chaerilida and Pseudochactida are synonymized with Buthida new parvordinal synonymies .

scholarly journals Molecular biogeography and diversification of the endemic terrestrial fauna of the Hawaiian Islands

2008 ◽  
Vol 363 (1508) ◽  
pp. 3363-3376 ◽  
Author(s):  
Robert H Cowie ◽  
Brenden S Holland
Keyword(s):  
Evolutionary Biology ◽  
Oceanic Islands ◽  
Single Origin ◽  
Morphological Taxonomy ◽  
Island Species ◽  
Source Regions ◽  
Crane Flies ◽  
Geographic Origins ◽  
Molecular Studies ◽  
Molecular Biogeography

Oceanic islands have played a central role in biogeography and evolutionary biology. Here, we review molecular studies of the endemic terrestrial fauna of the Hawaiian archipelago. For some groups, monophyly and presumed single origin of the Hawaiian radiations have been confirmed (achatinelline tree snails, drepanidine honeycreepers, drosophilid flies, Havaika spiders, Hylaeus bees, Laupala crickets). Other radiations are derived from multiple colonizations ( Tetragnatha and Theridion spiders, succineid snails, possibly Dicranomyia crane flies, Porzana rails). The geographic origins of many invertebrate groups remain obscure, largely because of inadequate sampling of possible source regions. Those of vertebrates are better known, probably because few lineages have radiated, diversity is far lower and morphological taxonomy permits identification of probable source regions. Most birds, and the bat, have New World origins. Within the archipelago, most radiations follow, to some degree, a progression rule pattern, speciating as they colonize newer from older islands sequentially, although speciation often also occurs within islands. Most invertebrates are single-island endemics. However, among multi-island species studied, complex patterns of diversification are exhibited, reflecting heightened dispersal potential (succineids, Dicranomyia ). Instances of Hawaiian taxa colonizing other regions are being discovered ( Scaptomyza flies, succineids). Taxonomy has also been elucidated by molecular studies ( Achatinella snails, drosophilids). While molecular studies on Hawaiian fauna have burgeoned since the mid-1990s, much remains unknown. Yet the Hawaiian fauna is in peril: more than 70 per cent of the birds and possibly 90 per cent of the snails are extinct. Conservation is imperative if this unique fauna is to continue shedding light on profound evolutionary and biogeographic questions.

The foundations of evolutionary genetics

2019 ◽  
pp. 1-24
Author(s):  
Glenn-Peter Sætre ◽  
Mark Ravinet
Keyword(s):  
Evolutionary Biology ◽  
Charles Darwin ◽  
Evolutionary Genetics ◽  
The Other ◽  
Future Developments ◽  
Key Concepts ◽  
History Of ◽  
Gregor Mendel ◽  
Ways Of Thinking

The fields of evolutionary biology and genetics were founded as separate disciplines in the mid-1800s, largely due to the works of Charles Darwin and Gregor Mendel respectively. It would, however, take decades before biologists finally understood the deep connection between the principles of heredity and the processes of evolution and that neither could be fully understood without the other. This chapter takes a brief look at the history of these disciplines, including how the key concepts, ideas, and technologies, fundamental to all of biology, were discovered and how these have affected our ways of thinking. Many important concepts are foreshadowed here that will be handled at greater depth in later chapters. The chapter ends with a brief review of important methods in contemporary evolutionary genetics and a hint towards future developments in the field.

INTRODUCTION: WHY VICTORIAN NATURAL HISTORY?

2007 ◽  
Vol 35 (2) ◽  
pp. 539-549 ◽  
Author(s):  
Barbara T. Gates
Keyword(s):  
Natural History ◽  
George Eliot ◽  
Charles Darwin ◽  
British Museum ◽  
The Other ◽  
Mary Kingsley ◽  
Charles Lyell ◽  
Gender Barriers ◽  
And Gender ◽  
Joseph Hooker

VICTORIANS WERE IN LOVE WITHnatural history. David Allen describes their passion as a series of crazes – over geology, over shells, and over ferns, as in pteridomania (mania over ferns) – to cite just a very few examples. Lynn Merrill, on the other hand, delineates a more comprehensive, cultural romance, one extending over many years. Whatever we choose to call this love, we are still in the process of discovering just how deep and lasting it was. Like many love affairs, it was marked at first by a blush enthusiasm and fascination with otherness. This was followed by curiosity and a rage to risk self in the quest to know more about the other – and sometimes, as a result, by ridiculous missteps. Think of George Eliot and George Henry Lewes sloshing around at the seashore, ill-equipped but determined to find out enough to write about what they were trying to capture and study. Or recall Mary Kingsley out in Africa in a canoe propelled by several Congolese, tumbling out of the boat but saving her trusted copy of Albert Günther's 1880Introduction to the Study of Fishes, tenacious in her desire to bring back labeled specimens to the British Museum of Natural history. Earlier, in a similarly resolute quest to record birdlife, John and Elizabeth Gould globe-trotted to the extent that they put Elizabeth's life and their growing family at risk. And people like explorer/naturalist Thomas Bowdich died of fever for their fervor over natural history, in Bowdich's case as he worked to detail facts about specimens in Porto Santo, off the coast of West Africa. Bowdich left a wife to fend for herself and their family via her own study of natural history, and one result was Sara Bowdich Lee's beautifully illustratedFresh-Water Fishes of Great Britain(1828). The romance with nature certainly cut across class and gender barriers. Stonecutter Hugh Miller could lose himself as easily in geological pursuits as could Charles Darwin or Sir Charles Lyell and Marianne North's passion for plants may well have matched or exceeded that of Kew's famous botanist, Sir Joseph Hooker.

Victorian Pain

2017 ◽  
Author(s):  
Rachel Ablow
Keyword(s):  
Nineteenth Century ◽  
Victorian Literature ◽  
Social Life ◽  
Charles Darwin ◽  
Harriet Martineau ◽  
The Status ◽  
History Of ◽  
The Individual ◽  
Natural Philosophers ◽  
First Time

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.

Sphagnum mosses (Sphagnaceae, Bryophyta) of mires Chefandzar and Masota in North Ossetia (Caucasus)

2018 ◽  
Vol 52 (2) ◽  
pp. 455-462 ◽  
Author(s):  
G. Ya. Doroshina ◽  
I. A. Nikolajev
Keyword(s):  
Plant Communities ◽  
The Other ◽  
North Caucasus ◽  
Sphagnum Mosses ◽  
Greater Caucasus ◽  
The North ◽  
First Time ◽  
North Ossetia

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.

An Epistemological Criticism of Social Entrepreneurship: Is Social Entrepreneurship a Sound Scientific Field of Research

2018 ◽  
Author(s):  
Amir Forouharfar
Keyword(s):  
Social Entrepreneurship ◽  
Social Constructivism ◽  
Social Epistemology ◽  
American English ◽  
Meta Analysis ◽  
Research Question ◽  
Knowledge Structure ◽  
Scientific Field ◽  
The Other ◽  
First Time

The paper was shaped around the pivotal question: Is SE a sound and scientific field of research? The question has given a critical tone to the paper and has also helped to bring out some of the controversial debates in the realm of SE. The paper was organized under five main discussions to be able to provide a scientific answer to the research question: (1)<b> </b>is “social entrepreneurship” an oxymoron?, (2) the characteristics of SE knowledge, (3) sources of social entrepreneurship knowledge, (4) SE knowledge: structure and limitations and (5) contributing epistemology-making concepts for SE.<b> </b>Based on the sections,<b> </b>the study relied on the relevant philosophical schools of thought in <i>Epistemology </i>(e.g. <i>Empiricism</i>, <i>Rationalism</i>, <i>Skepticism</i>, <i>Internalism</i> vs. <i>Externalism</i>,<i> Essentialism, Social Constructivism</i>, <i>Social Epistemology, etc.</i>) to discuss these controversies around SE and proposes some solutions by reviewing SE literature. Also, to determine the governing linguistic discourse in the realm of SE, which was necessary for our discussion,<i> Corpus of Contemporary American English (COCA)</i> for the first time in SE studies was used. Further, through the study, SE buzzwords which constitute SE terminology were derived and introduced to help us narrowing down and converging the thoughts in this field and demarking the epistemological boundaries of SE. The originality of the paper on one hand lies in its pioneering discussions on SE epistemology and on the other hand in paving the way for a construction of sound epistemology for SE; therefore in many cases after preparing the philosophical ground for the discussions, it went beyond the prevalent SE literature through meta-analysis to discuss the cases which were raised. The results of the study verified previously claimed embryonic pre-paradigmatic phase in SE which was far from a sound and scientific knowledge, although the scholarly endeavors are the harbingers of such a possibility in the future which calls for further mature academic discussion and development of SE knowledge by the SE academia.

A Nabatean port on the Red Sea: note on the pottery finds from al-Qusayr (al-Wajh, Saudi Arabia)

2020 ◽  
Author(s):  
Caroline Durand
Keyword(s):  
Saudi Arabia ◽  
19Th Century ◽  
Red Sea ◽  
Point Of View ◽  
The Other ◽  
Trade Routes ◽  
Other Hand ◽  
Roman Egypt ◽  
Pottery Sherds ◽  
First Time

Al-Qusayr is located 40 km south of modern al-Wajh, roughly 7 km from the eastern Red Sea shore. This site is known since the mid-19th century, when the explorer R. Burton described it for the first time, in particular the remains of a monumental building so-called al-Qasr. In March 2016, a new survey of the site was undertaken by the al-‘Ula–al-Wajh Survey Project. This survey focused not only on al-Qasr but also on the surrounding site corresponding to the ancient settlement. A surface collection of pottery sherds revealed a striking combination of Mediterranean and Egyptian imports on one hand, and of Nabataean productions on the other hand. This material is particularly homogeneous on the chronological point of view, suggesting a rather limited occupation period for the site. Attesting contacts between Mediterranean merchants, Roman Egypt and the Nabataean kingdom, these new data allow a complete reassessment of the importance of this locality in the Red Sea trade routes during antiquity.

Status of Family Fissidentaceae in Gujarat

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
D.G. Shah ◽  
D.N. Mehta ◽  
R.V. Gujar
Keyword(s):  
Distinct Species ◽  
The State ◽  
The Other ◽  
Land Plants ◽  
Reproductive Structures ◽  
The Family ◽  
The Status ◽  
Vegetative Characters ◽  
First Time ◽  
Different Parts

Bryophytes are the second largest group of land plants and are also known as the amphibians of the plant kingdom. 67 species of bryophytes have been reported from select locations across the state of Gujrat. The status of family fissidentaceae which is a large moss family is being presented in this paper. Globally the family consists of 10 genera but only one genus, Fissidens Hedw. has been collected from Gujarat. Fissidens is characterized by a unique leaf structure and shows the presence of three distinct lamina, the dorsal, the ventral and the vaginant lamina. A total of 8 species of Fissidens have been reported from the state based on vegetative characters as no sporophyte stages were collected earlier. Species reported from the neighboring states also showed the absence of sporophytes. The identification of different species was difficult due to substantial overlap in vegetative characters. Hence a detailed study on the diversity of members of Fissidentaceae in Gujarat was carried out between November 2013 and February 2015. In present study 8 distinct species of Fissidens have been collected from different parts of the state. Three species Fissidens splachnobryoides Broth., Fissidens zollingerii Mont. and Fissidens curvato-involutus Dixon. have been identified while the other five are still to be identified. Fissidens zollingerii Mont. and Fissidens xiphoides M. Fleisch., which have been reported as distinct species are actually synonyms according to TROPICOS database. The presence of sexual reproductive structures and sporophytes for several Fissidens species are also being reported for the first time from the state.

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