scholarly journals The two-domain tree of life is linked to a new root for the Archaea

2015 ◽  
Vol 112 (21) ◽  
pp. 6670-6675 ◽  
Author(s):  
Kasie Raymann ◽  
Céline Brochier-Armanet ◽  
Simonetta Gribaldo

One of the most fundamental questions in evolutionary biology is the origin of the lineage leading to eukaryotes. Recent phylogenomic analyses have indicated an emergence of eukaryotes from within the radiation of modern Archaea and specifically from a group comprising Thaumarchaeota/“Aigarchaeota” (candidate phylum)/Crenarchaeota/Korarchaeota (TACK). Despite their major implications, these studies were all based on the reconstruction of universal trees and left the exact placement of eukaryotes with respect to the TACK lineage unclear. Here we have applied an original two-step approach that involves the separate analysis of markers shared between Archaea and eukaryotes and between Archaea and Bacteria. This strategy allowed us to use a larger number of markers and greater taxonomic coverage, obtain high-quality alignments, and alleviate tree reconstruction artifacts potentially introduced when analyzing the three domains simultaneously. Our results robustly indicate a sister relationship of eukaryotes with the TACK superphylum that is strongly associated with a distinct root of the Archaea that lies within the Euryarchaeota, challenging the traditional topology of the archaeal tree. Therefore, if we are to embrace an archaeal origin for eukaryotes, our view of the evolution of the third domain of life will have to be profoundly reconsidered, as will many areas of investigation aimed at inferring ancestral characteristics of early life and Earth.

2018 ◽  
Vol 3 (2) ◽  
pp. 103
Author(s):  
Rama Beka Sariy ◽  
Betty Yosephin Simanjuntak ◽  
Desri Suryani

Infants who fail to grow much occur in the third month or fourth month of early life. Early breastfeeding of the ASI causes mothers not to give breast milk and cause infectious diseases that result in stunting in infants. The purpose of this research is to find out the relationship of early breastfeeding with nutritional status (PB/U) age 4-7 months in Ratu Samban Sub-district of Bengkulu City.  This research uses analytic observational with a cross-sectional design. The results showed the nutritional status of PB / U short category 18.3% and MP ASI early 66.7% while the statistical test showed probability (p) of 0.273 (p> 0.05).  There is no correlation between early breastfeeding of MP and nutritional status of PB / U age 4-7 months in Ratu Samban Sub-district of Bengkulu City. Need to do re-research a using Cohort method and with other variables.Bayi yang gagal tumbuh banyak terjadi pada bulan ketiga atau bulan ke empat awal kehidupan. Pemberian MP ASI dini mengakibatkan ibu tidak berusaha memberikan ASI dan menyebabkan terjadinya penyakit infeksi yang mengakibatkan stunting pada balita. Tujuan dari penelitian ini adalah untuk mengetahui hubungan pemberian MP-ASI dini dengan status gizi (PB/U) pada bayi usia 4-7 bulan di Kecamatan Ratu Samban Kota Bengkulu. Jenis penelitian ini menggunakan observasional analitik dengan desain cross sectional. Hasil penelitian menunjukan status gizi PB/U kategori pendek 18,3% dan MP ASI dini 66,7% sedangkan uji statistik menunjukkan nilai probabilitas (p) sebesar 0,273 (p > 0,05).  Tidak ada hubungan antara pemberian MP ASI dini dengan status gizi PB/U usia 4-7 bulan di Kecamatan Ratu Samban Kota Bengkulu . Hal ini berkaitan dengan pemberian makanan pendamping ASI sementara sebagai makanan prelaktal sebelum ASI ibu keluar dan diberikan dalam jumlah sedikit. Lebih baik dilakukan penelitian lanjutan dengan menggunakan metode Kohort dan dengan variabel lain.


Author(s):  
Andrew Briggs ◽  
Hans Halvorson ◽  
Andrew Steane

Two scientists and a philosopher aim to show how science both enriches and is enriched by Christian faith. The text is written around four themes: 1. God is a being to be known, not a hypothesis to be tested; 2. We set a high bar on what constitutes good argument; 3. Uncertainty is OK; 4. We are allowed to open up the window that the natural world offers us. This is not a work of apologetics. Rather, the text takes an overview of various themes and gives reactions and responses, intended to place science correctly as a valued component of the life of faith. The difference between philosophical analysis and theological reflection is expounded. Questions of human identity are addressed from philosophy, computer science, quantum physics, evolutionary biology and theological reflection. Contemporary physics reveals the subtle and open nature of physical existence, and offers lessons in how to learn and how to live with incomplete knowledge. The nature and role of miracles is considered. The ‘argument from design’ is critiqued, especially arguments from fine-tuning. Logical derivation from impersonal facts is not an appropriate route to a relationship of mutual trust. Mainstream evolutionary biology is assessed to be a valuable component of our understanding, but no exploratory process can itself fully account for the nature of what is discovered. To engage deeply in science is to seek truth and to seek a better future; it is also an activity of appreciation, as one may appreciate a work of art.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Vikas Kumar ◽  
Kaomud Tyagi ◽  
Rajasree Chakraborty ◽  
Priya Prasad ◽  
Shantanu Kundu ◽  
...  

AbstractThe complete mitochondrial genome of Lyrognathus crotalus is sequenced, annotated and compared with other spider mitogenomes. It is 13,865 bp long and featured by 22 transfer RNA genes (tRNAs), and two ribosomal RNA genes (rRNAs), 13 protein-coding genes (PCGs), and a control region (CR). Most of the PCGs used ATN start codon except cox3, and nad4 with TTG. Comparative studies indicated the use of TTG, TTA, TTT, GTG, CTG, CTA as start codons by few PCGs. Most of the tRNAs were truncated and do not fold into the typical cloverleaf structure. Further, the motif (CATATA) was detected in CR of nine species including L. crotalus. The gene arrangement of L. crotalus compared with ancestral arthropod showed the transposition of five tRNAs and one tandem duplication random loss (TDRL) event. Five plesiomophic gene blocks (A-E) were identified, of which, four (A, B, D, E) retained in all taxa except family Salticidae. However, block C was retained in Mygalomorphae and two families of Araneomorphae (Hypochilidae and Pholcidae). Out of 146 derived gene boundaries in all taxa, 15 synapomorphic gene boundaries were identified. TreeREx analysis also revealed the transposition of trnI, which makes three derived boundaries and congruent with the result of the gene boundary mapping. Maximum likelihood and Bayesian inference showed similar topologies and congruent with morphology, and previously reported multi-gene phylogeny. However, the Gene-Order based phylogeny showed sister relationship of L. crotalus with two Araneomorphae family members (Hypochilidae and Pholcidae) and other Mygalomorphae species.


2011 ◽  
Vol 81 (1-2) ◽  
pp. 32-42 ◽  
Author(s):  
Yoshiyuki Ishitani ◽  
Sohta A. Ishikawa ◽  
Yuji Inagaki ◽  
Masashi Tsuchiya ◽  
Kozo Takahashi ◽  
...  

Author(s):  
Sara Fuentes-Soriano ◽  
Elizabeth A. Kellogg

Physarieae is a small tribe of herbaceous annual and woody perennial mustards that are mostly endemic to North America, with its members including a large amount of variation in floral, fruit, and chromosomal variation. Building on a previous study of Physarieae based on morphology and ndhF plastid DNA, we reconstructed the evolutionary history of the tribe using new sequence data from two nuclear markers, and compared the new topologies against previously published cpDNA-based phylogenetic hypotheses. The novel analyses included ca. 420 new sequences of ITS and LUMINIDEPENDENS (LD) markers for 39 and 47 species, respectively, with sampling accounting for all seven genera of Physarieae, including nomenclatural type species, and 11 outgroup taxa. Maximum parsimony, maximum likelihood, and Bayesian analyses showed that these additional markers were largely consistent with the previous ndhF data that supported the monophyly of Physarieae and resolved two major clades within the tribe, i.e., DDNLS (Dithyrea, Dimorphocarpa, Nerisyrenia, Lyrocarpa, and Synthlipsis)and PP (Paysonia and Physaria). New analyses also increased internal resolution for some closely related species and lineages within both clades. The monophyly of Dithyrea and the sister relationship of Paysonia to Physaria was consistent in all trees, with the sister relationship of Nerisyrenia to Lyrocarpa supported by ndhF and ITS, and the positions of Dimorphocarpa and Synthlipsis shifted within the DDNLS Clade depending on the employed data set. Finally, using the strong, new phylogenetic framework of combined cpDNA + nDNA data, we discussed standing hypotheses of trichome evolution in the tribe suggested by ndhF.


Mammalia ◽  
2019 ◽  
Vol 83 (2) ◽  
pp. 180-189 ◽  
Author(s):  
Adam W. Ferguson ◽  
Houssein R. Roble ◽  
Molly M. McDonough

AbstractThe molecular phylogeny of extant genets (Carnivora, Viverridae,Genetta) was generated using all species with the exception of the Ethiopian genetGenetta abyssinica. Herein, we provide the first molecular phylogenetic assessment ofG. abyssinicausing molecular sequence data from multiple mitochondrial genes generated from a recent record of this species from the Forêt du Day (the Day Forest) in Djibouti. This record represents the first verified museum specimen ofG. abyssinicacollected in over 60 years and the first specimen with a specific locality for the country of Djibouti. Multiple phylogenetic analyses revealed conflicting results as to the exact relationship ofG. abyssinicato otherGenettaspecies, providing statistical support for a sister relationship to all other extant genets for only a subset of mitochondrial analyses. Despite the inclusion of this species for the first time, phylogenetic relationships amongGenettaspecies remain unclear, with limited nodal support for many species. In addition to providing an alternative hypothesis of the phylogenetic relationships among extant genets, this recent record provides the first complete skeleton of this species to our knowledge and helps to shed light on the distribution and habitat use of this understudied African small carnivore.


2011 ◽  
Vol 48 (1) ◽  
Author(s):  
Dina Ribbink ◽  
Christian Hofer ◽  
Martin Dresner

An investigation is conducted on the effect of financial distress on customer service levels in the U.S. airline industry. Using data from the first quarter of 1998 to the third quarter of 2006, we employ a seemingly unrelated regressions (SUR) model to analyze the impact of financial distress on three measures of customer service. We find that higher financial distress is associated with better on-time performance of airlines and fewer lost bags. The relationship of airline financial distress to the number of bumped customers, however, is insignificant.


2008 ◽  
Vol 5 (2) ◽  
pp. 243-248
Author(s):  
Baghdad Science Journal

Age and growth of Varicorhinus damascinus (Val.) in Tigris river at Salahuldin province have been investigated. Monthly samples were taken during the period from September 1999 to August 2000, using small-meshed gill nets. The age data showed that there were six age groups and the dominant age groups were (III – IV) for both sexes. The results of the present study revealed that the increment in length of V. damascinus at the sites of study showed a tendency to decrease with the increase in age, after the third year of life in both sexes. The length-weight relationship of males and females were calculated and demonstrated in a straight line logarithmic formula, as follows: Log W = 1.5404 + 2.6885 log L for males r = 0.95 (P > 0.05) Log W = 1.6723 + 2.7877 log L for females r = 0.77 (P > 0.05) The values of the regression coefficient (b) indicated that the growth of both sexes of V. damascinus was allometric..


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