rapid diversification
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2022 ◽  
Author(s):  
Hejraneh Azizi ◽  
Masoud Sheidai ◽  
Valiollah Mozaffarian ◽  
Zahra Noormohammadi

Abstract Tragopogon L. (Cichorioideae, Lactuceae, Scorzonerinae) is an Old World genus with 150 species, Rechinger in Flora Iranica divided this genus in 13 section and 37 species that 26 species of them are exist in Iran. Safavi et al. divided it into 26 species without sections in flora Iran. Despite the anatomical and molecular studies done around the world, the exact classification of this genus is not clear due to the high number of secret species, hybridization, polyploidy and rapid diversification. The morphology studies of 32 species and Molecular studies (ISSR, ITS, cp DNA) of 22 species of the genus Tragopogon was investigated . The purpose of these studies are classification and determination of interspecific relationship in this genus. Sections of Rubriflori, Sosnowskya, Chromopappus, Majores, Angustissimi, Krascheninnikovia in flora of Iranica are confirmed on the basis of morphometry and molecular data. Section of Profundisulcati in flora Iranica is confirmed on the base of morphometry data. The Species of T. jesdianus, T . porphyrocephalus, T. rezaiyensis and T. Stroterocarpus in the flora of Iranica are not classified in any section which we classified in the Rubriflori section, Cp DNA dendrogram are not useful for classification in this genus and Chloroplast sequences are very similar among Tragopogon species, Therefore, the use of cp DNA markers in the classification of this genus is not recommended.


Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 91
Author(s):  
Qingxiang Guo ◽  
Christopher M. Whipps ◽  
Yanhua Zhai ◽  
Dan Li ◽  
Zemao Gu

Nematocysts are secretory organelles in cnidarians that play important roles in predation, defense, locomotion, and host invasion. However, the extent to which nematocysts contribute to adaptation and the mechanisms underlying nematocyst evolution are unclear. Here, we investigated the role of the nematocyst in cnidarian evolution based on eight nematocyst proteomes and 110 cnidarian transcriptomes/genomes. We detected extensive species-specific adaptive mutations in nematocyst proteins (NEMs) and evidence for decentralized evolution, in which most evolutionary events involved non-core NEMs, reflecting the rapid diversification of NEMs in cnidarians. Moreover, there was a 33–55 million year macroevolutionary lag between nematocyst evolution and the main phases of cnidarian diversification, suggesting that the nematocyst can act as a driving force in evolution. Quantitative analysis revealed an excess of adaptive changes in NEMs and enrichment for positively selected conserved NEMs. Together, these findings suggest that nematocysts may be key to the adaptive success of cnidarians and provide a reference for quantitative analyses of the roles of phenotypic novelties in adaptation.


2021 ◽  
Vol 224 (24) ◽  
Author(s):  
Ali Seleit ◽  
Satoshi Ansai ◽  
Kazunori Yamahira ◽  
Kawilarang W. A. Masengi ◽  
Kiyoshi Naruse ◽  
...  

ABSTRACT A remarkable diversity of lateral line patterns exists in adult teleost fishes, the basis of which is largely unknown. By analysing the lateral line patterns and organ numbers in 29 Oryzias species and strains we report a rapid diversification of the lateral line system within this genus. We show a strong dependence of lateral line elaboration (number of neuromasts per cluster, number of parallel lateral lines) on adult species body size irrespective of phylogenetic relationships. In addition, we report that the degree of elaboration of the anterior lateral line, posterior lateral line and caudal neuromast clusters is tightly linked within species, arguing for a globally coordinated mechanism controlling lateral line organ numbers and patterns. We provide evidence for a polygenic control over neuromast numbers and positioning in the genus Oryzias. Our data also indicate that the diversity in lateral lines can arise as a result of differences in patterning both during embryonic development and post-embryonically, where simpler embryonic patterns generate less complex adult patterns and organ numbers, arguing for a linkage between the two processes.


2021 ◽  
Author(s):  
Joan Ferrer Obiol ◽  
Helen F. James ◽  
R. Terry Chesser ◽  
Vincent Bretagnolle ◽  
Jacob González‐Solís ◽  
...  

2021 ◽  
Author(s):  
Biao-Feng Zhou ◽  
Shuai Yuan ◽  
Andrew Crowl ◽  
Yi-Ye Liang ◽  
Yong Shi ◽  
...  

Abstract Northern Hemisphere forests changed drastically in the early Eocene with the diversification of the oak family (Fagaceae). Cooling climates over the next 20 million years fostered the spread of temperate biomes that became increasingly dominated by oaks and their chestnut relatives. Here we investigate the timing and pattern of major macroevolutionary events and ancient genome-wide signatures of hybridization across Fagaceae. An unparalleled transformation of forest dynamics began with the rapid diversification of major lineages within 15 million years following the K-Pg extinction. Innovations related to seed and pollen dispersal are implicated in triggering waves of continental radiations, while fungal symbioses fortified a competitive edge underground. We detected introgression at multiple time scales, including ancient events predating the origination of genus-level diversity. As oak lineages moved into newly available temperate habitats in the early Miocene, secondary contact between previously isolated species occurred. This resulted in adaptive introgression, further amplifying global proliferation.


2021 ◽  
Author(s):  
Xing Wang ◽  
Jean Vannier ◽  
Xiaoguang Yang ◽  
Lucas Leclère ◽  
Qiang Ou ◽  
...  

Although fossil evidence suggest that various animal groups were able to move actively through their environment in the early stages of their evolution, virtually no direct information is available on the nature of their muscle systems. The origin of jellyfish swimming, for example, is of great concern to biologists. Exceptionally preserved muscles are described here in benthic peridermal olivooid medusozoans from the basal Cambrian of China (Kuanchuanpu Formation, ca. 535 Ma) that have direct equivalent in modern medusozoans. They consist of circular fibers distributed over the bell surface (subumbrella) and most probably have a myoepithelial origin. This is the oldest record of a muscle system in cnidarians and more generally in animals. This basic system was probably co-opted by younger early Cambrian jellyfish to develop capacities for the jet-propelled swimming within the water column. Additional lines of fossil evidence obtained from ecdysozoans (worms and panarthropods) show that the muscle systems of early animals underwent a rapid diversification through the early Cambrian and increased their capacity to colonize a wide range of habitats both within the water column and sediment at a critical time of their evolutionary radiation.


2021 ◽  
Author(s):  
Gabriel Machado Matos ◽  
Michael D Lewis ◽  
Carlos Talavera-Lopez ◽  
Matthew Yeo ◽  
Edmundo C Grisard ◽  
...  

Protozoa and fungi are known to have extraordinarily diverse mechanisms of genetic exchange. However, the presence and epidemiological relevance of genetic exchange in Trypanosoma cruzi, the agent of Chagas disease, has been controversial and debated for many years. Field studies have identified both predominantly clonal and sexually recombining natural populations. Two of six natural T. cruzi lineages (TcV and TcVI) show hybrid mosaicism, using analysis of single-gene locus markers. The formation of hybrid strains in vitro has been achieved and this provides a framework to study the mechanisms and adaptive significance of genetic exchange. Using whole genome sequencing of a set of experimental hybrids strains, we have confirmed that hybrid formation initially results in tetraploid parasites. The hybrid progeny showed novel mutations that were not attributable to either (diploid) parent showing an increase in amino acid changes. In long-term culture, up to 800 generations, there was progressive, gradual erosion of progeny genomes towards triploidy, yet retention of elevated copy number was observed at several core housekeeping loci. Our findings indicate hybrid formation by fusion of diploid T. cruzi, followed by sporadic genome erosion, but with substantial potential for adaptive evolution, as has been described as a genetic feature of other organisms, such as some fungi.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Huijuan Zhou ◽  
Yiheng Hu ◽  
Aziz Ebrahimi ◽  
Peiliang Liu ◽  
Keith Woeste ◽  
...  

Abstract Background The walnut family (Juglandaceae) contains commercially important woody trees commonly called walnut, wingnut, pecan and hickory. Phylogenetic relationships and diversification within the Juglandaceae are classic and hot scientific topics that have been elucidated by recent fossil, morphological, molecular, and (paleo) environmental data. Further resolution of relationships among and within genera is still needed and can be achieved by analysis of the variation of chloroplast, mtDNA, and nuclear genomes. Results We reconstructed the backbone phylogenetic relationships of Juglandaceae using organelle and nuclear genome data from 27 species. The divergence time of Juglandaceae was estimated to be 78.7 Mya. The major lineages diversified in warm and dry habitats during the mid-Paleocene and early Eocene. The plastid, mitochondrial, and nuclear phylogenetic analyses all revealed three subfamilies, i.e., Juglandoideae, Engelhardioideae, Rhoipteleoideae. Five genera of Juglandoideae were strongly supported. Juglandaceae were estimated to have originated during the late Cretaceous, while Juglandoideae were estimated to have originated during the Paleocene, with evidence for rapid diversification events during several glacial and geological periods. The phylogenetic analyses of organelle sequences and nuclear genome yielded highly supported incongruence positions for J. cinerea, J. hopeiensis, and Platycarya strobilacea. Winged fruit were the ancestral condition in the Juglandoideae, but adaptation to novel dispersal and regeneration regimes after the Cretaceous-Paleogene boundary led to the independent evolution of zoochory among several genera of the Juglandaceae. Conclusions A fully resolved, strongly supported, time-calibrated phylogenetic tree of Juglandaceae can provide an important framework for studying classification, diversification, biogeography, and comparative genomics of plant lineages. Our addition of new, annotated whole chloroplast genomic sequences and identification of their variability informs the study of their evolution in walnuts (Juglandaceae).


2021 ◽  
Vol 9 ◽  
Author(s):  
Nicole Nova

Coronaviruses cause respiratory and digestive diseases in vertebrates. The recent pandemic, caused by the novel severe acute respiratory syndrome (SARS) coronavirus 2, is taking a heavy toll on society and planetary health, and illustrates the threat emerging coronaviruses can pose to the well-being of humans and other animals. Coronaviruses are constantly evolving, crossing host species barriers, and expanding their host range. In the last few decades, several novel coronaviruses have emerged in humans and domestic animals. Novel coronaviruses have also been discovered in captive wildlife or wild populations, raising conservation concerns. The evolution and emergence of novel viruses is enabled by frequent cross-species transmission. It is thus crucial to determine emerging coronaviruses' potential for infecting different host species, and to identify the circumstances under which cross-species transmission occurs in order to mitigate the rate of disease emergence. Here, I review (broadly across several mammalian host species) up-to-date knowledge of host range and circumstances concerning reported cross-species transmission events of emerging coronaviruses in humans and common domestic mammals. All of these coronaviruses had similar host ranges, were closely related (indicative of rapid diversification and spread), and their emergence was likely associated with high-host-density environments facilitating multi-species interactions (e.g., shelters, farms, and markets) and the health or well-being of animals as end- and/or intermediate spillover hosts. Further research is needed to identify mechanisms of the cross-species transmission events that have ultimately led to a surge of emerging coronaviruses in multiple species in a relatively short period of time in a world undergoing rapid environmental change.


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