Taxonomic Resemblance Research Articles

Characterization of halotolerant microalga isolated from waterlogged habitats: Deciphering the biochemical profiling and unraveling the molecular identity.

The primary objective of this study was to comprehensively explore the biochemical profile of the novel halotolerant microalgae strain, biogas laboratory scenedesmus (BGLRS), previously isolated from waterlogged regions in the southwest zone of Punjab, India. To achieve this, three distinct drying methods viz. freeze-drying, oven-drying, and shade-drying were employed and biochemical composition and antioxidant analyses on the microalgal biomass were conducted. Utilizing advanced analytical techniques, including high-performance liquid chromatography (HPLC), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and gas chromatography-mass spectroscopy (GC-MS) on freeze-dried biomass, its carbohydrate profile, micronutrient composition, and presence of bioactive compounds with potential therapeutic and nutraceutical significance were sought to unravel. Among the drying methods evaluated, freeze-drying exhibited the most promising experimental results, prompting its selection for further investigation. Notably, ICP-AES unveiled elevated concentrations of essential elements such as calcium, iron, magnesium, and phosphorus in BGLRS, with negligible traces of heavy metals, underscoring its safety for human consumption. GC-MS analysis further divulged the existence of numerous biologically active compounds, indicating potential applications in medical and nutraceutical fields. Through molecular identification using sequencing of the internal transcribed spacer (ITS) region, a close taxonomic resemblance between BGLRS and Scenedesmus sp. MKB was established, solidifying its unique position within the microalgal taxonomy. The deposition of ITS sequences into the NCBI GenBank, obtaining accession number MN796425, attests to the rigor and transparency of this research. Overall, these findings strongly suggest that microalgae BGLRS possesses high-quality biochemical attributes of significant therapeutic and nutraceutical importance.

Cellular content of biomolecules in sub-seafloor microbial communities

Microbial biomolecules, typically from the cell envelope, can provide crucial information about distribution, activity, and adaptations of sub-seafloor microbial communities. However, when cells die these molecules can be preserved in the sediment on timescales that are likely longer than the lifetime of their microbial sources. Here we provide for the first time measurements of the cellular content of biomolecules in sedimentary microbial cells. We separated intact cells from sediment matrices in samples from surficial, deeply buried, organic-rich, and organic-lean marine sediments by density centrifugation. Amino acids, amino sugars, muramic acid, and intact polar lipids were analyzed in both whole sediment and cell extract, and cell separation was optimized and evaluated in terms of purity, separation efficiency, taxonomic resemblance, and compatibility to high-performance liquid chromatography and mass spectrometry for biomolecule analyses. Because cell extracts from density centrifugation still contained considerable amounts of detrital particles and non-cellular biomolecules, we further purified cells from two samples by fluorescence-activated cell sorting (FACS). Cells from these highly purified cell extracts had an average content of amino acids and lipids of 23–28fgcell−1 and 2.3fgcell−1, respectively, with an estimated carbon content of 19–24fgcell−1. In the sediment, the amount of biomolecules associated with vegetative cells was up to 70-fold lower than the total biomolecule content. We find that the cellular content of biomolecules in the marine subsurface is up to four times lower than previous estimates. Our approach will facilitate and improve the use of biomolecules as proxies for microbial abundance in environmental samples and ultimately provide better global estimates of microbial biomass.

Taxonomic Diversity and Taxonomic Dominance: The Example of Forest Plantations in South-Central Chile

The study describes an analysis of the impact of plantation forestry on the taxonomic diversity of plants in south-central Chile. In this biodiversity hotspot, plantations of non-native species like Pinus radiata D. Don, Eucalyptus globules Labill. and Populus nigra L. have largely replaced native deciduous and sclerophyllous forests. The study compares taxonomic diversity of commercial plantations and native forests using taxonomic distinctness and diversity and the Simpson diversity index. Most of these indexes attest a considerably reduced taxonomic diversity to plantations. However, taxonomic distinctness values for P. radiata plantations seem to contradict other indexes at first glance. It is shown that the higher values of taxonomic distinctness of P. radiata plantations come from taxonomic dominance. Taxonomic dominance describes the fact that P. radiate—a member of the infradivison of Gymnospermae-bears only little taxonomic resemblance to other plants, which are Angiospermae. Thus, it strongly dominates the taxonomic distinctness index and the high taxonomic resemblance of other plant within its plots is neglected. Indexes are developed that identify such dominant species and adjust for taxonomic dominance in taxonomic diversity analyses. After this adjustment, all indexes provide a coherent image on taxonomic diversity. Plantation forestry produces a considerable decline of taxonomic diversity. Taxonomic diversity analysis provides valuable insights in biodiversity impacts and complements standard analyses.

Comparative analysis of morphological and behavioral characters in the domestic dog and their importance in the reconstruction of phylogenetic relationships in canids

Relationships among 25 dog breeds, classified a priori by their respective ancestral trunks, were studied using data from 29 morphological and 13 behavioral characteristics. Although a certain correlation was found between both types of traits (r = 0.13; P < 0.05), this relationship was not manifested, regarding the level of racial classification, in the obtained dendrograms. The relationships between breeds obtained from morphological data were more congruent than those obtained from behavioral data when compared with phylogenies from other sources of information (mainly electrophoretic analysis). This indicates that the morphological characters could give more and better complementary information than the behavioral ones in the reconstruction of the phylogenetic relationships of canids. The mean character difference (MCD), used as a measure of taxonomic resemblance between breeds, had a value of 0.53 (± 0.12 STD), and was of a magnitude very similar to that obtained in other domestic animal species (cattle, horse, sheep and goats), indicating that a similar degree of morphological differences between breeds of these species exists.

Numerical Taxonomy of Nitrogen-Fixing "Decarboxylase-Negative" Vibrio Species Isolated from Aquatic Environments

A total of 95 strains of the genus Vibrio were studied by using numerical taxonomic techniques to determine phenotypic relationships among “decarboxylase-negative” strains, nitrogen-fixing (15N method) strains, and other members of the Vibrionaceae. Taxonomic resemblance was estimated on the basis of 129 tests by using Euclidean distance. Most strains clustered in phena, enabling identification with existing type strains. Nitrogen-fixing strains of Vibrio natriegens were identified, but other nitrogen-fixing isolates could not be assigned to any specific species or biovar.

Antigenic heterogeneity among influenza A(H3N2) field isolates during an outbreak in 1982/83, estimated by methods of numerical taxonomy.

Fourteen influenza A(H3N2) field isolates, mainly obtained during the first weeks of the 1982/83 influenza epidemic in The Netherlands, and nine influenza A(H3N2) reference strains were examined by means of haemagglutination inhibition (HI) tests with 23 polyclonal ferret sera. The resulting HI patterns were subjected to various methods of numerical taxonomy using, among others, taxonomic distance and correlation between strains for resemblance coefficients. Marked differences between distance and correlation coefficients were found in strains which differed in avidity only. The field isolates could be divided into four groups in respect of their taxonomic resemblance to the reference strains. The same grouping was found for five of the field isolates by testing these against 200 human sera.

A numerical taxonomic study of species of Vibrio isolated from the aquatic environment and birds in Kent, England.

A numerical taxonomic study has been carried out to confirm the identity of strains of the family Vibrionaceae isolated during an ecological study. A total of 237 strains were studied including 148 from the aquatic environment, 6 from estuarine birds, 1 from sheep faeces, and 61 control cultures. Duplicates of 21 of the strains were randomly selected and included to estimate test and operator error. Taxonomic resemblance was estimated on the basis of 148 characters using Euclidean distance. The taxonomic position of some strains was reevaluated using the pattern different coefficient. Strains were clustered by three methods, all of which gave similar results. The estimated average probability of test error was 1.5%. Strains previously identified as Vibrio anguillarum fell into four distinct phenons corresponding to V. anguillarum biovar I, 'V. anguillarum biovar II', V. diazotrophicus, and strains pathogenic to oyster larvae. The latter group characteristically degraded xanthine and probably represents a new species. The phenon corresponding to V. cholerae included the type strain, strains of human origin, and strains isolated in the United Kingdom from birds and the aquatic environment. Some strains of V. cholerae were luminous. Other phenons were identified as V. metschnikovii, V. fluvialis, and Aeromonas spp.

Mammalian biochronology of the late Cenozoic basins of New Mexico

Late Cenozoic mammalian remains have been collected from New Mexico for more than a century. The most important nineteenth-century collections came from the Espanola Basin. Work in this century has continued to focus mainly on the Miocene faunas in that basin and the northern part of the adjoining Albuquerque basin. The lithostratigraphy of these basins has recently been reviewed and revised, but the description of the large collections of fossil remains from the basinal deposits is largely incomplete. Pliocene and early Pleistocene faunas have been found in deposits that mark the development of external drainage of the major rivers of the state. Study of these assemblages has been cursory, although the lithostratigraphy of these deposits has received considerable attention in recent years. The Miocene basinal deposits accumulated under conditions of internal drainage in local structural environments that led to the development of partly synchronous depositional records. Biostratigraphies worked out in each basin overlap sufficiently so that the composite succession forms an important biochronological standard for southwestern North America. The Espanola and Albuquerque-Belen basins contain the only Miocene faunas of importance presently known in New Mexico. Their fossil records complement one another in that the northern Albuquerque basin has the only adequate representation of the early Miocene and the Espanola basin a more complete record of the medial and late Miocene. Synchronous faunas in these basins show a high degree of taxonomic resemblance extending to elements that represent endemic taxa or forms rare elsewhere. Compared with coevel assemblages in the Great Plains, there is considerable generic and specific similarity. This allows easy reference of the New Mexican faunal succession to the sequence of North American mammal ages that are essentially typified by the Great Plains biochronology. In addition to these taxonomic relationships, the New Mexican faunas retain throughout the Miocene characters that may typify a southwestern faunal province. The general features of the latter would include diverse and abundant artiodactyls, especially Camelidae, including a late occurrence of endemic stenomyline genera, and less diverse and abundant perissodactyls, especially horses, when compared with the Great Plains. The fossil vertebrate record of Pliocene and early Pleistocene time in New Mexico is largely confined to the basins of the Rio Grande and the Gila River and is derived from deposits of the axial rivers that were the percursors of the modern streams and from the piedmont slope facies of the basin margins. Sites scattered along the length of the Rio Grande rift from the Santo Domingo basin near Santa Fe south to the international border have yielded Blancan and early Irvington faunas. These assemblages can be arranged in temporal order from their position in local stratigraphic columns, from their biological affinities, and with respect to dated basalts and ashes interbedded in the sediments containing the fossil remains. Important reference sequences are available in adjacent Arizona and Texas, where mammalian faunas and calibrated biochronologies compare closely with those in New Mexico. The New Mexican record supports the southwestern biochronology for Pliocene and early Pleistocene time, including the following events and their calibration: the last appearance of hipparionine horses ( Nannippus ) and the first appearance of the South American immigrants, the glyptodont Glyptotherium and probably the mylodontid sloth genus Glossotherium , were nearly synchronous events close to the Gauss-Matuyama boundary (2.5 m.y. B.P.); at least three species Equus were present in the Southwest by the time of the Nannippus extinction; the first appearance of the Asiatic immigrant Mammuthus in the southwest between 1.2 and 1.4 m.y., postdating the Olduvai Event and, by definition, indicating that the Blancan-Irvingtonian boundary, at least as determined for the Southwest, lies close to the beginning of medial Pleistocene time.

Distributional model for marine isopod crustaceans and its bearing on early Paleozoic paleozoogeography and continental drift

Multivariate analysis of Holocene marine isopod faunas from the Arctic, Antarctic, northwestern Atlantic, southeastern Pacific, and northwestern Pacific regions confirms that on a global scale, generic-level faunal resemblance is highest between cold-water biofacies regardless of water depth or latitude. In general, warm-water biofacies are most similar to each other and least similar to cold-water biofacies. These faunal trends are apparently related to the division of the present world oceans into two general thermal realms: the psychrosphere, consisting of cold high-latitude shallow waters and deep waters at all latitudes; and the thermosphere, consisting of mainly lower latitude warm waters and temperature-variable waters above the permanent thermocline. Analogous trends in faunal resemblance and distributional characteristics have been documented for some Late Cambrian trilobite faunas, and they probably also existed during other parts of the Cambrian and during at least some parts of the Ordovician. This suggests that a two-layered thermally stratified ocean may have existed during some parts of the early Paleozoic. Regional trends in taxonomic resemblance during present thermal stratification of the world oceans suggest by analogy that early Paleozoic paleozoogeographic data are inconclusive for reconstruction of Paleozoic predrift continental positions. Concomitantly, taxonomic resemblance between early Paleozoic vagile benthic faunas cannot be used with complete fidelity to critically “test” continental reconstructions that have been based primarily on geological or geophysical evidence.

An Inconsistency between Protein Resemblance and Taxonomic Resemblance: Immunological Comparison of Diverse Proteins from Gallinaceous Birds

The comparative study of proteins is being used with greater frequency to produce information concerning genetic differences among species. Such studies make it increasingly evident that there may not be a strict correlation between degree of genetic difference and degree of difference at the supramolecular or organismal level. This point can be illustrated by the results of comparing proteins from the Domestic Chicken (Gallus gallus) with those of the Domestic Turkey (Meleagris gallopavo) and the Ring-necked Pheasant (Phasianus colchicus). We present evidence from our studies at the protein level that appears to contrast with the evidence at the organismal level regarding the degree of resemblance among these species. According to most ornithologists, the pheasant is more similar in anatomy and way of life to the chicken than is the turkey. This view is reflected in the system of bird classification which traditionally puts pheasants together with the chicken in the subfamily Phasianinae of the family Phasianidae, whereas the turkey is assigned to another family, Meleagrididae (Wetmore 1960). In the last two decades, however, evidence from hybridization experiments (Asmundson and Lorenz 1957; Olsen 1960; Poole 1963), chromosome studies (Stenius et al. 1962), electrophoretic patterns of protein mixtures (Sibley 1960, Sibley and Ahlquist 1972), immunological comparison of cell surfaces (Mainardi 1963), and the study of additional anatomical characters (Holman 1964, Hudson et al. 1966) has made it less certain that the turkey is as distant from the chicken as once thought. Consequently, Brodkorb (1964), Storer (1971), and Sibley and Ahlquist (1972) eliminated the family Meleagrididae and placed the turkey in the family Phasianidae. Nevertheless, these authors kept the turkey outside the subfamily Phasianinae. There seems to be unanimous

RECENT TRENDS IN NUMERICAL TAXONOMY

SummaryRecent trends in numerical taxonomy, with special reference to the classification of flowering plants, are reviewed. These advances are discussed under the following broad headings: the choice and scoring of characters and OTU's; the estimation of taxonomic resemblance; the representation of taxonomic structure; cladistics; and discrimination and identification. There is considerable activity on problems involving homology, numerical coefficients of resemblance, and clustering methods. The numerical study of cladistics is also of special interest, but it poses some very difficult problems. It is now evident that numerical methods can yield acceptable classifications, and they much increase taxonomic understanding of the groups that are examined. They are also valuable in many other branches of systematics.

The Inappropriateness of the Correlation Coefficient as a Measure of Taxonomic Resemblance

Journal Article The Inappropriateness of the Correlation Coefficient as a Measure of Taxonomic Resemblance Get access David C. Eades David C. Eades Search for other works by this author on: Oxford Academic PubMed Google Scholar Systematic Biology, Volume 14, Issue 2, June 1965, Pages 98–100, https://doi.org/10.2307/2411731 Published: 01 June 1965