Morphological evolution of the bivalvePtychomyathrough the Lower Cretaceous of Argentina

Paleobiology ◽  
2018 ◽  
Vol 44 (1) ◽  
pp. 101-117
Author(s):  
Pablo S. Milla Carmona ◽  
Darío G. Lazo ◽  
Ignacio M. Soto
Keyword(s):  
Time Series ◽  
Morphological Variation ◽  
Morphological Evolution ◽  
The Other ◽  
Upward Trend ◽  
Shell Size ◽  
Evolutionary Patterns ◽  
Upper Hauterivian ◽  
Patterns And Processes ◽  
Early Late

AbstractThe complex morphological evolution of the bivalvePtychomyathroughout the well-studied Agrio Formation in the Neuquén Basin (west-central Argentina, lower/upper Valanginian–lowest Barremian) constitutes an ideal opportunity to study evolutionary patterns and processes occurring at geological timescales. Ptychomyais represented in this unit by four species, the morphological variation of which needs to be temporally assessed to obtain a thorough picture of the evolution of the group. Here we use geometric morphometrics to measure variation in shell outline, ribbing pattern, and shell size in these species. We bracket the ages of our samples using a combination of ammonoid biostratigraphy and absolute ages and study the anagenetic pattern of evolution of each trait by means of paleontological time-series analysis and change tracking. We find that evolution inPtychomyais mostly speciational, as the majority of traits show stasis, with the exceptions of shell size inP. coihuicoensisand shell outline inP. windhauseni, which seem to evolve directionally toward larger and higher shells, respectively.Ptychomyadisplays changes in its average morphology and disparity, which are the result of a mixture of taxonomic turnover and mosaic evolution of traits. Pulses of speciation would have been triggered by ecological opportunity, as they occur during the recovery of shallow-burrowing bivalve faunas after dysoxic events affecting the basin. On the other hand, the presence of directional patterns of evolution inP. coihuicoensisandP. windhauseniseems to be the result of a general shallowing-upward trend observed in the basin during the upper Hauterivian–lowest Barremian, as opposed to the cyclical paleoenvironmental stability inferred for the early/late Valanginian–early Hauterivian, which would have prompted stasis inP. koeneniandP. esbelta.

scholarly journals Universal rules of life: metabolic rates, biological times and the equal fitness paradigm

2021 ◽  
Author(s):  
Joseph Burger ◽  
Chen Hou ◽  
Charles Hall ◽  
James Brown
Keyword(s):  
Structure And Function ◽  
The Other ◽  
Metabolic Rates ◽  
Synthetic Theory ◽  
Evolutionary Patterns ◽  
Single Origin ◽  
The One ◽  
Patterns And Processes ◽  
And Function ◽  
Dynamics Of Populations

Here we review and extend the equal fitness paradigm (EFP) as an important step in developing and testing a synthetic theory of ecology and evolution based on energy and metabolism. The EFP states that all organisms are equally fit at steady state, because they allocate the same quantity of energy, ~22.4 kJ/g/generation to production of offspring. On the one hand, the EFP may seem tautological, because equal fitness is necessary for the origin and persistence of biodiversity. On the other hand, the EFP reflects universal laws of life: how biological metabolism – the uptake, transformation and allocation of energy – links ecological and evolutionary patterns and processes across levels of organization from: i) structure and function of individual organisms, ii) life history and dynamics of populations, iii) interactions and coevolution of species in ecosystems. The physics and biology of metabolism have facilitated the evolution of millions of species with idiosyncratic anatomy, physiology, behavior and ecology but also with many shared traits and tradeoffs that reflect the single origin and universal rules of life.

scholarly journals Lineage Identification Affects Estimates of Evolutionary Mode in Marine Snails

2020 ◽  
Vol 69 (6) ◽  
pp. 1106-1121
Author(s):  
Felix Vaux ◽  
Michael R Gemmell ◽  
Simon F K Hills ◽  
Bruce A Marshall ◽  
Alan G Beu ◽  
...  
Keyword(s):  
Morphological Variation ◽  
Morphological Evolution ◽  
Morphological Data ◽  
Shell Shape ◽  
Shape Variation ◽  
Shell Size ◽  
Evolutionary Pattern ◽  
Pattern And Process ◽  
Marine Snails ◽  
Extant Species

Abstract In order to study evolutionary pattern and process, we need to be able to accurately identify species and the evolutionary lineages from which they are derived. Determining the concordance between genetic and morphological variation of living populations, and then directly comparing extant and fossil morphological data, provides a robust approach for improving our identification of lineages through time. We investigate genetic and shell morphological variation in extant species of Penion marine snails from New Zealand, and extend this analysis into deep time using fossils. We find that genetic and morphological variation identify similar patterns and support most currently recognized extant species. However, some taxonomic over-splitting is detected due to shell size being a poor trait for species delimitation, and we identify incorrect assignment of some fossil specimens. We infer that a single evolutionary lineage (Penion sulcatus) has existed for 22 myr, with most aspects of shell shape and shell size evolving under a random walk. However, by removing samples previously classified as the extinct species P. marwicki, we instead detect morphological stasis for one axis of shell shape variation. This result demonstrates how lineage identification can change our perception of evolutionary pattern and process. [Genotyping by sequencing; geometric morphometrics; morphological evolution; Neogastropoda; phenotype; speciation; stasis.]

Producers' Response to Changes in Prices and Marketing Policies: A Case Study of Sugarcane and Paddy in Eastern U.P. by S. C. Gupta and A. Majid. New York: Asia Publishing House, 1965.

1968 ◽  
Vol 8 (2) ◽  
pp. 308-309
Author(s):  
Mohammad Irshad Khan
Keyword(s):  
New York ◽  
Time Series ◽  
Time Series Data ◽  
Publishing House ◽  
Economic Incentives ◽  
The Other ◽  
Series Data ◽  
Poor Countries ◽  
Northern India

It is alleged that the agricultural output in poor countries responds very little to movements in prices and costs because of subsistence-oriented produc¬tion and self-produced inputs. The work of Gupta and Majid is concerned with the empirical verification of the responsiveness of farmers to prices and marketing policies in a backward region. The authors' analysis of the respon¬siveness of farmers to economic incentives is based on two sets of data (concern¬ing sugarcane, cash crop, and paddy, subsistence crop) collected from the district of Deoria in Eastern U.P. (Utter Pradesh) a chronically foodgrain deficit region in northern India. In one set, they have aggregate time-series data at district level and, in the other, they have obtained data from a survey of five villages selected from 170 villages around Padrauna town in Deoria.

scholarly journals The Connections between COVID-19 and the Energy Commodities Prices: Evidence through the Dynamic Time Warping Method

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 4024
Author(s):  
Krzysztof Dmytrów ◽  
Joanna Landmesser ◽  
Beata Bieszk-Stolorz
Keyword(s):  
Time Series ◽  
Palm Oil ◽  
Dynamic Time Warping ◽  
Global Economy ◽  
Price Change ◽  
Commodity Prices ◽  
The Other ◽  
Time Warping ◽  
Heating Oil ◽  
Dynamic Time

The main objective of the study is to assess the similarity between the time series of energy commodity prices and the time series of daily COVID-19 cases. The COVID-19 pandemic affects all aspects of the global economy. Although this impact is multifaceted, we assess the connections between the number of COVID-19 cases and the energy commodities sector. We analyse these connections by using the Dynamic Time Warping (DTW) method. On this basis, we calculate the similarity measure—the DTW distance between the time series—and use it to group the energy commodities according to their price change. Our analysis also includes finding the time shifts between daily COVID-19 cases and commodity prices in subperiods according to the chronology of the COVID-19 pandemic. Our findings are that commodities such as ULSD, heating oil, crude oil, and gasoline are weakly associated with COVID-19. On the other hand, natural gas, palm oil, CO2 allowances, and ethanol are strongly associated with the development of the pandemic.

scholarly journals Morphological variation in Leptorhynchos squamatus (Gnaphalieae: Asteraceae)

2002 ◽  
Vol 15 (2) ◽  
pp. 205 ◽  
Author(s):  
Christina Flann ◽  
Pauline Y. Ladiges ◽  
Neville G. Walsh
Keyword(s):  
High Altitude ◽  
Morphological Variation ◽  
Environmental Conditions ◽  
Leaf Size ◽  
Alpine Plants ◽  
The Other ◽  
Herbarium Specimens ◽  
South Eastern ◽  
Eastern Australia ◽  
Low Altitude

A study of morphological variation in Leptorhynchos squamatus (Labill.) Less. across its range in south-eastern Australia was undertaken to test the hypothesis that L. squamatus includes two taxa. Phenetic pattern analyses of both field-collected and herbarium specimens on the basis of morphology confirmed two major groups. Bract, cypsela, pappus bristle and leaf characters were particularly important in separating the two groups. The taxa are separated by altitude differences with one being a low-altitude plant found in many habitats and the other being a high-altitude taxon that is a major component of alpine meadows. Lowland plants have dark bract tips, fewer and wider pappus bristles than alpine plants, papillae on the cypselas and more linear leaves. A somewhat intermediate population from the Major Mitchell Plateau in the Grampians shows some alpine and some lowland characters but is included in the lowland taxon. Seeds from five populations (two alpine, two lowland and Major Mitchell) were germinated and plants grown for 18 weeks under four controlled sets of environmental conditions. The experiment showed that leaf size and some other characters are affected by environmental conditions, but that there are underlying genetic differences between the lowland and alpine forms. Leptorhynchos squamatus subsp. alpinus Flann is described here to accommodate the highland taxon.

Demographic changes and savings behavior: the experience of a developing country

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ebrahim Rezaei
Keyword(s):  
Time Series ◽  
Demographic Data ◽  
Calculated Data ◽  
The Other ◽  
Demographic Changes ◽  
Savings Behavior ◽  
Content Type ◽  
Household Level ◽  
Savings Rate ◽  
The Government

PurposeThis paper aims to disclose the savings behavior of Iran's economy in the context of demographic transition.Design/methodology/approachEmploying a version of Ramsey-Cass-Koopmans growth model, this paper benefits from a broad range of data and variables which are mainly taken from the Central Bank of Iran's database. The study uses actual and calculated data to produce analogous simulated data. The data cover the 1970–2015 period. This long period provides an opportunity to simulate more valid time series. It is worth noting that due to the severe economic sanctions imposed on the Iran's economy, particularly after 2017, some most recent data have been obliterated from the sample.FindingsThe results, stemming from the simulated model, hint that; firstly, the population variable is a notable determinant of the savings rate. Secondly, the effects of a slump in the population growth rate would attenuate the savings level significantly. Thirdly, other pragmatic steps could be taken to redress the fallout of the demographic changes.Research limitations/implicationsThere are some limitations in providing broad data related to economic sectors in Iran. The savings data, for instance, are available as an aggregated time series, and if the authors had wide data of household level, they would have been able to build more detail-based model. Similar to this issue of lack of households’ income-based data, some measures such as high or low levels as well as detailed demographic data could be helpful in sophisticated household level resulting. In addition, the complex relationship between the government and social security (pension) funds, in terms of financing part of government's budget deficit by these funds, thwarts a typical researcher in using comprehensive and transparent government expenditure data in their research. In other words, the possible positive or negative role of the funds, as a related issue to the demographic changes, cannot simply be determined in the model. It might be possible after necessary corrections are carried out in the mentioned relations.Originality/valueIn fact, the problem statement in this paper is to discern how the population aging can impact the saving rates on the one hand, and to what extent its repercussion can be modified by the other theoretical-based determinants on the other. In fact, the underlying argument of the present research arises from the stylized facts concerning prognosticates of the future evolutions of the world's population. To that end, the study will use Iran's economic and demographic data.

Evolutionary Patterns and Processes in Ferns

1979 ◽  
Vol 69 (1) ◽  
pp. 16
Author(s):  
David B. Lellinger ◽  
J. D. Lovis
Keyword(s):  
Evolutionary Patterns ◽  
Patterns And Processes

scholarly journals On the volatility of sensex

2012 ◽  
Vol 1 (1) ◽  
pp. 10-22
Author(s):  
Nateson C ◽  
Suganya D
Keyword(s):  
Time Series ◽  
Time Series Data ◽  
The Other ◽  
Stock Index ◽  
Series Data ◽  
Closing Time ◽  
Market Activity ◽  
Year 2000 ◽  
Daily Returns

The present study seeks to analyse Volatility of popular stock index SENSEX. The present study is based on the closing time series data of SENSEX covering the period from 3rd January 2000, to 30th June 2011. The year 2008 has recorded higher Volatility compared to the other years of the study. Volatility fell in the year 2009 from the high of 2008. The years after were comparatively calmer. In the year 2000, the Volatility was higher signifying enhance market activity. The overall daily Volatility for SENSEX was approximately 1.70 % while the annualized value was approximately 25%-26%. Events Reported around Daily Returns in Excess of +/-5%have also been identified.

Variation and change in instrument noun formation in Hebrew and its relation to the verbal system

2015 ◽  
Vol 8 (1) ◽  
pp. 1-28 ◽  
Author(s):  
Lior Laks
Keyword(s):  
Morphological Change ◽  
Morphological Variation ◽  
The Other ◽  
Prosodic Structure ◽  
Thematic Role ◽  
Verbal System ◽  
Base Form ◽  
Thematic Relation

This paper examines morphological variation and change in the formation of instrument nouns in Hebrew. The change is always from one of the non-participle templates into a participle template and never the other way around. Nonetheless, not all instrument nouns (INs) change their template. I contend that the transition to the participle templates can be predicted based on systematic criteria. Such a change targets both morphological and thematic transparency between the IN and the related verb. Thematically, the participle IN corresponds to a thematic role that the verb assigns. The IN has to be agentive in order to be thematically transparent and undergo morphological change. The more transparent the thematic relation between the verb and the IN is, the greater the chance for morphological change. Morphologically, the formation of the participle form is also more transparent as it requires fewer changes between the verb and the IN. The only changes that occur are affixation and changing the vowels of the base verb, and the formation in the participle templates preserves the prosodic structure of the base verb. The analysis also provides further support to the stem modification theory and shows that the formation of the instrument noun is based on internal changes on the verbal base form without separate reference to the consonantal root.

Redescription of Mastigias papua (Scyphozoa, Rhizostomeae) with designation of a neotype and recognition of two additional species

Zootaxa ◽  
2018 ◽  
Vol 4457 (4) ◽  
pp. 520 ◽  
Author(s):  
MARIANA ROCHA DE SOUZA ◽  
MICHAEL N DAWSON
Keyword(s):  
Pacific Islands ◽  
Parallel Evolution ◽  
Morphological Characters ◽  
The Philippines ◽  
Type Specimens ◽  
Additional Species ◽  
Evolutionary Patterns ◽  
Molecular Analyses ◽  
Taxonomic Approach ◽  
Patterns And Processes

Mastigias, the ‘golden’ or ‘spotted’ jellyfish, is distributed throughout the Indo-Pacific. Specimens are identified routinely as Mastigias papua, although eight species were described historically, and molecular analyses evince at least three phylogenetic species. Understanding species diversity in Mastigias has become a priority because of its growing relevance in studies of boom-bust dynamics related to environmental change, cryptic species, local adaptation, parallel evolution, and peripatric speciation. However, species delimitation and identification are inhibited by a dearth of type specimens for most species, including M. papua. We address these issues by resampling Mastigias from the type locality in Waigeo, West Papua, as well as in the Philippines, and by comparing cytochrome c oxidase subunit I and up to 34 morphological characters of 268 Mastigias specimens from surrounding regions in the Indo-Pacific. We also gathered data from the historical descriptions of the eight species of Mastigias to estimate the identity of the two other currently revealed clades. Using this integrative taxonomic approach, we re-describe Mastigias papua as endemic to the tropical western Pacific islands (including Papua, Palau, Enewetak) and designate a neotype for the species. Additionally, based on morphological similarity and geographic overlap, we identified a second clade most probably as M. albipunctatus (from Japan, Komodo, Berau and Philippines) and a third clade tentatively as either M. andersoni or M. ocellatus. This study highlights the benefits of combining molecular analyses, samples from type locations, traditional descriptions and statistical analyses of morphological variation in systematic studies, and the concomitant potential of such studies to increase understanding of evolutionary patterns and processes in Scyphozoa.

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