scholarly journals Species delimitation and hybridisation history of a hazel species complex

2021 ◽  
Author(s):  
Zhiqiang Lu ◽  
Yongshuai Sun ◽  
Ying Li ◽  
Yongzhi Yang ◽  
Gaini Wang ◽  
...  

Abstract Background and Aims Hybridisation increases species adaptation and biodiversity but also obscures species boundaries. In this study, species delimitation and hybridisation history were examined within one Chinese hazel species complex (Corylus chinensis–Corylus fargesii). Two species including four varieties have already been described for this complex, with overlapping distributions. Methods A total of 322 trees from 44 populations of these four varieties across their ranges were sampled for morphological and molecular analyses. Climatic datasets based on 108 geographical locations were used to evaluate their niche differentiations. Flowering phenology was also observed for two co-occurring species or varieties. Key Results Four statistically different phenotypic clusters were revealed, but these clusters were highly inconsistent with the traditional taxonomic groups. All the clusters showed statistically distinct niches, with complete or partial geographic isolation. Only two clusters displayed a distributional overlap, but they had distinct flowering phenologies at the site where they co-occurred. Population-level evidence based on the genotypes of 10 simple sequence repeat (SSR) loci supported four phenotypic clusters. In addition, one cluster was shown to have an admixed genetic composition derived from the other three clusters through repeated historical hybridisations. Conclusions Based on our new evidence, it is better to treat the four clusters identified here as four independent species. One of them was shown to have an admixed genetic composition derived from the other threes through repeated historical hybridisations. This study highlights the importance of applying integrative and statistical methods to infer species delimitations and hybridisation history. Such a protocol should be adopted widely for future taxonomic studies.

2017 ◽  
Vol 8 ◽  
Author(s):  
Honglei Zheng ◽  
Liqiang Fan ◽  
Richard I. Milne ◽  
Lei Zhang ◽  
Yaling Wang ◽  
...  

2008 ◽  
Vol 21 (4) ◽  
pp. 289 ◽  
Author(s):  
Zoë F. Smith ◽  
Elizabeth A. James ◽  
Cassandra B. McLean

Taxa within the Diuris punctata species complex exhibit high levels of variation at both species and population level. Morphometric data collected in situ were used to investigate species boundaries of four Victorian Diuris species within the Diuris punctata species complex. Morphological characters and taxonomic groups identified in the present study were compared to those described under the current taxonomic treatment. Sixty-five multistate and continuous characters, including seven vegetative and 58 floral characters, were measured in situ across the range of each species within Victoria. The importance of flower colour in distinguishing taxa was highlighted but characters used were generally indiscrete. Certain characters used in current taxonomic descriptions, e.g. floral fragrance, were found to be uninformative. D. fragrantissima was confirmed as a separate taxon within the D. punctata group, justifying its recognition as a unique entity for conservation. Clustering of D. daltonii within D. punctata suggests that the recent elevation of the D. punctata var. daltonii to species level is not justified. The in situ measurement of morphological characters made it possible to incorporate sufficient sampling to encompass intra-specific and intra-population variation and is a feasible method to overcome sampling limitations encountered when herbarium specimens and limited destructive sampling are used.


2016 ◽  
Vol 85 (2) ◽  
pp. 123-145 ◽  
Author(s):  
Fabio Scarpa ◽  
Piero Cossu ◽  
Tiziana Lai ◽  
Daria Sanna ◽  
Marco Curini-Galletti ◽  
...  

Given the pending biodiversity crisis, species delimitation is a critically important task in conservation biology, but its efficacy based on single lines of evidence has been questioned as it may not accurately reflect species limits and relationships. Hence, the use of multiple lines of evidence has been portrayed as a means to overcome identification issues arising from gene/species tree discordance, morphological convergence or recent adaptive radiations. Here, the integrative taxonomic approach has been used to address the study of the Monocelis lineataspecies complex. The taxonomic resolution of the complex is challenging, as the species lacks sclerotised copulatory structures, which as a rule of thumb aid identification in Proseriata. Eighteen populations, which encompass most of the geographic range of the complex, were studied using morphology, karyology, crossbreeding experiments and molecular analysis. These different markers provided evidence of four (karyology) to eight (morphology) discrete entities, whereas crossings showed various degrees of intersterility among the tested populations. Molecular species delimitation revealed a different number of candidate species, spanning from five (ABGD and K/θ) to 11 (GMYC). Such incongruences reflect the multifaceted evolutionary history of M. lineata s.l.and hamper the full taxonomic resolution of the complex. However, two candidate species were consistently validated by all of the markers and are described as new species: Monocelis algicolanov. sp. and M. exquisitanov. sp. The latter species appear to have a restricted distribution, and the possibility that meiofaunal taxa may be of conservation concern is discussed.


2020 ◽  
Author(s):  
Nathan P. Havill ◽  
Brian P. Griffin ◽  
Jeremy C. Andersen ◽  
Robert G. Foottit ◽  
Mathias J. Justesen ◽  
...  

Author(s):  
Colby Dickinson

In his somewhat controversial book Remnants of Auschwitz, Agamben makes brief reference to Theodor Adorno’s apparently contradictory remarks on perceptions of death post-Auschwitz, positions that Adorno had taken concerning Nazi genocidal actions that had seemed also to reflect something horribly errant in the history of thought itself. There was within such murderous acts, he had claimed, a particular degradation of death itself, a perpetration of our humanity bound in some way to affect our perception of reason itself. The contradictions regarding Auschwitz that Agamben senses to be latent within Adorno’s remarks involve the intuition ‘on the one hand, of having realized the unconditional triumph of death against life; on the other, of having degraded and debased death. Neither of these charges – perhaps like every charge, which is always a genuinely legal gesture – succeed in exhausting Auschwitz’s offense, in defining its case in point’ (RA 81). And this is the stance that Agamben wishes to hammer home quite emphatically vis-à-vis Adorno’s limitations, ones that, I would only add, seem to linger within Agamben’s own formulations in ways that he has still not come to reckon with entirely: ‘This oscillation’, he affirms, ‘betrays reason’s incapacity to identify the specific crime of Auschwitz with certainty’ (RA 81).


2017 ◽  
Vol 39 (2) ◽  
pp. 265-276 ◽  
Author(s):  
Kas Saghafi

In several late texts, Derrida meditated on Paul Celan's poem ‘Grosse, Glühende Wölbung’, in which the departure of the world is announced. Delving into the ‘origin’ and ‘history’ of the ‘conception’ of the world, this paper suggests that, for Derrida, the end of the world is determined by and from death—the death of the other. The death of the other marks, each and every time, the absolute end of the world.


2019 ◽  
Vol 188 (1) ◽  
pp. 95-146
Author(s):  
Martin Bohatý ◽  
Dalibor Velebil

Adalbert Wraný (*1836, †1902) was a doctor of medicine, with his primary specialization in pediatric pathology, and was also one of the founders of microscopic and chemical diagnostics. He was interested in natural sciences, chemistry, botany, paleontology and above all mineralogy. He wrote two books, one on the development of mineralogical research in Bohemia (1896), and the other on the history of industrial chemistry in Bohemia (1902). Wraný also assembled several natural science collections. During his lifetime, he gave to the National Museum large collections of rocks, a collection of cut precious stones and his library. He donated a collection of fossils to the Geological Institute of the Czech University (now Charles University). He was an inspector of the mineralogical collection of the National Museum. After his death, he bequeathed to the National Museum his collection of minerals and the rest of the gemstone collection. He donated paintings to the Prague City Museum, and other property to the Klar Institute of the Blind in Prague. The National Museum’s collection currently contains 4 325 samples of minerals, as well as 21 meteorites and several hundred cut precious stones from Wraný’s collection.


2019 ◽  
Vol 1 (1) ◽  
pp. 5-14
Author(s):  
Carlos Alvaréz Teijeiro

Emmanuel Lévinas, the philosopher of ethics par excellence in the twentieth century, and by own merit one of the most important ethical philosophers in the history of western philosophy, is also the philosopher of the Other. Thereby, it can be said that no thought has deepened like his in the ups and downs of the ethical relationship between subject and otherness. The general objective of this work is to expose in a simple and understandable way some ideas that tend to be quite dark in the philosophical work of the author, since his profuse religious production will not be analyzed here. It is expected to show that his ideas about the being and the Other are relevant to better understand interpersonal relationships in times of 4.0 (re)evolution. As specific objectives, this work aims to expose in chronological order the main works of the thinker, with special emphasis on his ethical implications: Of the evasion (1935), The time and the Other (1947), From the existence to the existent (1947), Totality and infinity: An essay on exteriority (1961) and, last, Otherwise than being, or beyond essence (1974). In the judgment of Lévinas, history of western philosophy starting with Greece, has shown an unusual concern for the Being, this is, it has basically been an ontology and, accordingly, it has relegated ethics to a second or third plane. On the other hand and in a clear going against the tide movement, our author supports that ethics should be considered the first philosophy and more, even previous to the proper philosophize. This novel approach implies, as it is supposed, that the essential question of the philosophy slows down its origin around the Being in order to inquire about the Other: it is a philosophy in first person. Such a radical change of perspective generates an underlying change in how we conceive interpersonal relationships, the complex framework of meanings around the relationship Me and You, which also philosopher Martin Buber had already spoken of. As Lévinas postulates that ethics is the first philosophy, this involves that the Other claims all our attention, intellectual and emotional, to the point of considering that the relationship with the Other is one of the measures of our identity. Thus, “natural” attitude –husserlian word not used by Lévinas- would be to be in permanent disposition regarding to the meeting with the Other, to be in permanent opening state to let ourselves be questioned by him. Ontology, as the author says, being worried about the Being, has been likewise concerned about the Existence, when the matter is to concern about the particular Existent that every otherness supposes for us. In conclusion it can be affirmed that levinasian ethics of the meeting with the Other, particular Face, irreducible to the assumption, can contribute with an innovative looking to (re)evolving the interpersonal relationships in a 4.0 context.


1995 ◽  
Vol 31 (8) ◽  
pp. 301-309 ◽  
Author(s):  
Govert D. Geldof

In integrated water management, the issues are often complex by nature, they are capable of subjective interpretation, are difficult to express in standards and exhibit many uncertainties. For such issues, an equilibrium approach is not appropriate. A non-equilibrium approach has to be applied. This implies that the processes to which the integrated issue pertains, are regarded as “alive”’. Instead of applying a control system as the model for tackling the issue, a network is used as the model. In this network, several “agents”’ are involved in the modification, revision and rearrangement of structures. It is therefore an on-going renewal process (perpetual novelty). In the planning process for the development of a groundwater policy for the municipality of Amsterdam, a non-equilibrium approach was adopted. In order to do justice to the integrated character of groundwater management, an approach was taken, containing the following features: (1) working from global to detailed, (2) taking account of the history of the system, (3) giving attention to communication, (4) building flexibility into the establishing of standards, and (5) combining reason and emotions. A middle course was sought, between static, rigid but reliable on the one hand; dynamic, flexible but vague on the other hand.


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