scholarly journals Resequencing 545 ginkgo genomes across the world reveals the evolutionary history of the living fossil

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Yun-Peng Zhao ◽  
Guangyi Fan ◽  
Ping-Ping Yin ◽  
Shuai Sun ◽  
Ning Li ◽  
...  

Abstract As Charles Darwin anticipated, living fossils provide excellent opportunities to study evolutionary questions related to extinction, competition, and adaptation. Ginkgo (Ginkgo biloba L.) is one of the oldest living plants and a fascinating example of how people have saved a species from extinction and assisted its resurgence. By resequencing 545 genomes of ginkgo trees sampled from 51 populations across the world, we identify three refugia in China and detect multiple cycles of population expansion and reduction along with glacial admixture between relict populations in the southwestern and southern refugia. We demonstrate multiple anthropogenic introductions of ginkgo from eastern China into different continents. Further analyses reveal bioclimatic variables that have affected the geographic distribution of ginkgo and the role of natural selection in ginkgo’s adaptation and resilience. These investigations provide insights into the evolutionary history of ginkgo trees and valuable genomic resources for further addressing various questions involving living fossil species.

2020 ◽  
Vol 191 ◽  
pp. 20
Author(s):  
Cédric Chény ◽  
Elvis Guillam ◽  
André Nel ◽  
Vincent Perrichot

Embolemidae is a cosmopolitan but species-poor group of chrysidoid wasps with a scarce fossil record, despite a long evolutionary history since at least the Early Cretaceous. Here, the new species, Ampulicomorpha quesnoyensis sp. nov., is illustrated and described based on a single female found in Early Eocene amber of Oise (France). The new species is compared with the three other known fossil species of the genus, and a key to all fossil species of Ampulicomorpha is provided. This is the third European fossil species of Ampulicomorpha, which suggests that the genus was once well established in Western Europe while it is more widely distributed in the Eastern Palaearctic region today. A list of all fossil and extant Embolemidae of the world, as well as a map of their geographical distribution map, are provided.


Genetics ◽  
2003 ◽  
Vol 163 (1) ◽  
pp. 147-157 ◽  
Author(s):  
Arjun Sivasundar ◽  
Jody Hey

AbstractCaenorhabditis elegans has become one of the most widely used model research organisms, yet we have little information on evolutionary processes and recent evolutionary history of this widespread species. We examined patterns of variation at 20 microsatellite loci in a sample of 23 natural isolates of C. elegans from various parts of the world. One-half of the loci were monomorphic among all strains, and overall genetic variation at microsatellite loci was low, relative to most other species. Some population structure was detected, but there was no association between the genetic and geographic distances among different natural isolates. Thus, despite the nearly worldwide occurrence of C. elegans, little evidence was found for local adaptation in strains derived from different parts of the world. The low levels of genetic variation within and among populations suggest that recent colonization and population expansion might have occurred. However, the patterns of variation are not consistent with population expansion. A possible explanation for the observed patterns is the action of background selection to reduce polymorphism, coupled with ongoing gene flow among populations worldwide.


2019 ◽  
pp. 196-206
Author(s):  
Kimberley J. Hockings ◽  
Robin I.M. Dunbar

Humans and alcohol have shared a very long history. In this final chapter, we highlight some of the key findings that emerge from the chapters in this book, in particular the evolutionary history of our adaptation to alcohol consumption and the social role that alcohol consumption plays, and has played, in human societies across the world. This raises a major contradiction in the literature, namely the fact that, despite this long history, the medical profession typically views alcohol as destructive. We draw attention to several avenues that would repay future research and how humans’ relationship with alcohol stands to change and evolve.


2019 ◽  
Vol 11 (1) ◽  
pp. 447-451
Author(s):  
Ulrich Hambach ◽  
Ian Smalley

Abstract The two critical books, launching the study and appreciation of loess, were ‘Charakteristik der Felsarten’ (CdF) by Karl Caesar von Leonhard, published in Heidelberg by Joseph Engelmann, in 1823-4, and ‘Principles of Geology’ (PoG) by Charles Lyell, published in London by John Murray in 1830-3. Each of these books was published in three volumes and in each case the third volume contained a short piece on loess (about 2-4 pages). These two books are essentially the foundations of loess scholarship. In CdF Loess [Loefs] was first properly defined and described; section 89 in vol. 3 provided a short study of the nature and occurrence of loess, with a focus on the Rhine valley. In PoG there was a short section on loess in the Rhine valley; this was in vol.3 and represents the major dissemination of loess awareness around the world. A copy of PoG3 (Principles of Geology vol. 3) reached Charles Darwin on the Beagle in Valparaiso in 1834; worldwide distribution. Lyell and von Leonhard met in Heidelberg in 1832. Von Leonhard and Heinrich Georg Bronn (1800-1862) showed Lyell the local loess. These observations provided the basis for the loess section in PoG3. Lyell acknowledged the influence of his hosts when he added a list of loess scholars to PoG; by the 5th edition in 1837 the list comprised H.G. Bronn, Karl Caesar von Leonhard (1779-1862), Ami Boue (1794-1881), Voltz, Johann Jakob Noeggerath (1788-1877), J. Steininger, P. Merian, Rozet, C.F.H. von Meyer (1801-1869), Samuel Hibbert (1782-1848) and Leonard Horner (1785-1864); a useful list of loess pioneers. The loess is a type of ground that has only recently been established, and it seems, the peculiarity of the Rhine region, and of a very general but inconsistent spread.” H.G. Bronn 1830


2007 ◽  
Vol 19 (1-2) ◽  
pp. 103-132 ◽  
Author(s):  
David E. Marsh

This short history of evolutionary thought during the last few centuries describes how some of our foremost thinkers have debated – and still do – the precise mechanisms at the roots of evolutionary change. Commentators frequently contradicted themselves, as well as each other. The popularity of Christian fundamentalism waned following the World Wars. Eventually the rug was pulled from beneath it – till a more recent reaction. Amidst all this babble coming from numerous towers of Babel over centuries, we failed to see Charles Darwin as the great environmentalist: who said environmental conditions, whilst working hand in glove with natural selection, constituted the more important 'law.' A bird's eye view of 18th and 19th century evolutionary thought is considered against the climate of those times (politics, industrial revolution, trade, religious expansionism, etc). Darwinism superseded Lamarckism helped by the neo-Darwinism of Weismann, higher mathematics, population genetics – the 'Modern Synthesis' of 1935 – culminating in the discovery of the double helix by Watson, Crick et al, assuring us of the correctness of 'primacy of DNA theory'. Stimulation and challenge is currently fuelled by exciting nascent knowledge of epigenetic variations and Cairnsian 'adaptive mutations'. The work of Marcus Pembrey and Barry Keverne tracking human and animal variation back generationally describing how 'genomic imprinting' causes reversible heritable change from slight variations in the chromosomes of parents, grandparents, great-grandparents and parents to be. The purpose of this thesis is to put forward a new theme proposed neither by Lamarck or Darwin. We stand on the threshold of the first paradigm change for 150 years.


Parasitology ◽  
2017 ◽  
Vol 144 (13) ◽  
pp. 1752-1762 ◽  
Author(s):  
SCOTT P. LAWTON ◽  
LAUREN I. BOWEN ◽  
AIDAN M. EMERY ◽  
GÁBOR MAJOROS

SUMMARYHigh levels of molecular diversity were identified in mitochondrial cytochrome c oxidase (cox1) gene sequences of Schistosoma turkestanicum from Hungary. These cox1 sequences were all specific to Hungary which contrasted with the low levels of diversity seen in the nuclear internal transcribed spacer region (ITS) sequences, the majority of which were shared between China and Iran isolates. Measures of within and between host molecular variation within S. turkestanicum showed there to be substantial differences in molecular diversity, with cox1 being significantly more diverse than the ITS. Measures of haplotype frequencies revealed that each host contained its own subpopulation of genetically unique parasites with significant levels of differentiation. Pairwise mismatch analysis of cox1 sequences indicated S. turkestanicum populations to have a bimodal pairwise difference distribution and to be stable unlike the ITS sequences, which appeared to have undergone a recent population expansion event. Positive selection was also detected in the cox1 sequences, and biochemical modelling of the resulting protein illustrated significant mutational events causing an alteration to the isoelectric point of the cox1 protein, potentially altering metabolism. The evolutionary signature from the cox1 indicates local adaptation and long establishment of S. turkestanicum in Hungary with continual introgression of nuclear genes from Asian isolates. These processes have led to the occurrence of mito-nuclear discordance in a schistosome population


Symbiosis ◽  
2020 ◽  
Vol 80 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Ewa Sajnaga ◽  
Waldemar Kazimierczak

AbstractEntomopathogenic bacteria from the genera Photorhabdus and Xenorhabdus are closely related Gram-negative bacilli from the family Enterobacteriaceae (γ-Proteobacteria). They establish obligate mutualistic associations with soil nematodes from the genera Steinernema and Heterorhabditis to facilitate insect pathogenesis. The research of these two bacterial genera is focused mainly on their unique interactions with two different animal hosts, i.e. nematodes and insects. So far, studies of the mutualistic bacteria of nematodes collected from around the world have contributed to an increase in the number of the described Xenorhabdus and Photorhabdus species. Recently, the classification system of entomopatogenic nematode microsymbionts has undergone profound revision and now 26 species of the genus Xenorhabdus and 19 species of the genus Photorhabdus have been identified. Despite their similar life style and close phylogenetic origin, Photorhabdus and Xenorhabdus bacterial species differ significantly in e.g. the nematode host range, symbiotic strategies for parasite success, and arrays of released antibiotics and insecticidal toxins. As the knowledge of the diversity of entomopathogenic nematode microsymbionts helps to enable the use thereof, assessment of the phylogenetic relationships of these astounding bacterial genera is now a major challenge for researchers. The present article summarizes the main information on the taxonomy and evolutionary history of Xenorhabdus and Photorhabdus, entomopathogenic nematode symbionts.


2001 ◽  
Vol 24 (4) ◽  
pp. 618-625 ◽  
Author(s):  
Michael Kubovy ◽  
William Epstein

Shepard has supposed that the mind is stocked with innate knowledge of the world and that this knowledge figures prominently in the way we see the world. According to him, this internal knowledge is the legacy of a process of internalization; a process of natural selection over the evolutionary history of the species. Shepard has developed his proposal most fully in his analysis of the relation between kinematic geometry and the shape of the motion path in apparent motion displays. We argue that Shepard has made a case for applying the principles of kinematic geometry to the perception of motion, but that he has not made the case for injecting these principles into the mind of the percipient. We offer a more modest interpretation of his important findings: that kinematic geometry may be a model of apparent motion. Inasmuch as our recommended interpretation does not lodge geometry in the mind of the percipient, the motivation of positing internalization, a process that moves kinematic geometry into the mind, is obviated. In our conclusion, we suggest that cognitive psychologists, in their embrace of internal mental universals and internalization may have been seduced by the siren call of metaphor.


2018 ◽  
Author(s):  
Danièle Filiault ◽  
Evangeline S. Ballerini ◽  
Terezie Mandáková ◽  
Gökçe Aköz ◽  
Nathan Derieg ◽  
...  

AbstractThe columbine genus Aquilegia is a classic example of an adaptive radiation, involving a wide variety of pollinators and habitats. Here we present the genome assembly of A. coerulea ‘Goldsmith’, complemented by high-coverage sequencing data from 10 wild species covering the world-wide distribution. Our analyses reveal extensive allele sharing among species and demonstrate that introgression and selection played a role in the Aquilegia radiation. We also present the remarkable discovery that the evolutionary history of an entire chromosome differs from that of the rest of the genome – a phenomenon which we do not fully understand, but which highlights the need to consider chromosomes in an evolutionary context.


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