scholarly journals Evolutionary biology studies on the Iris pumila clonal plant: Advantages of a good model system, main findings and directions for further research

2012 ◽  
Vol 64 (1) ◽  
pp. 159-174 ◽  
Author(s):  
A. Tarasjev ◽  
S. Avramov ◽  
Danijela Miljkovic
Keyword(s):  
Evolutionary Biology ◽  
Scientific Literature ◽  
Clonal Plant ◽  
Population Based ◽  
Model System ◽  
Biological Organization ◽  
Evolutionary Studies ◽  
Iris Pumila ◽  
Published Research ◽  
Different Levels

Evolutionary studies on the dwarf bearded iris, Iris pumila L., a perennial clonal monocot with hermaphroditic enthomophylous flowers, have been conducted during the last three decades on plants and populations from the Deliblato Sands in Serbia. In this review we discuss the main advantages of this model system that have enabled various studies of several important genetic, ecological, and evolutionary issues at different levels of biological organization (molecular, physiological, anatomical, morphological and population). Based on published research and its resonance in international scientific literature, we present the main findings obtained from these studies, and discuss possible directions for further research.

Studying Populations of Online Communities

2019 ◽  
pp. 173-193
Author(s):  
Benjamin Mako Hill ◽  
Aaron Shaw
Keyword(s):  
Online Communities ◽  
Information Diffusion ◽  
Diffusion Processes ◽  
Empirical Studies ◽  
Population Level ◽  
Study Groups ◽  
Population Based ◽  
Large Majority ◽  
Community Processes ◽  
Published Research

While the large majority of published research on online communities consists of analyses conducted entirely within individual communities, this chapter argues for a population-based approach, in which researchers study groups of similar communities. For example, although there have been thousands of papers published about Wikipedia, a population-based approach might compare all wikis on a particular topic. Using examples from published empirical studies, the chapter describes five key benefits of this approach. First, it argues that population-level research increases the generalizability of findings. Next, it describes four processes and dynamics that are only possible to study using populations: community-level variables, information diffusion processes across communities, ecological dynamics, and multilevel community processes. The chapter concludes with a discussion of a series of limitations and challenges.

scholarly journals Circulating bioactive sclerostin levels in an Austrian population-based cohort

2021 ◽  
Author(s):  
Katharina Kerschan-Schindl ◽  
Ursula Föger-Samwald ◽  
Andreas Gleiss ◽  
Stefan Kudlacek ◽  
Jacqueline Wallwitz ◽  
...  
Keyword(s):  
Serum Levels ◽  
Population Based ◽  
Negative Regulator ◽  
Total Serum ◽  
Mineral Density ◽  
Cross Sectional ◽  
Robust Parameter ◽  
Austrian Population ◽  
Different Levels

Summary Background Circulating serum sclerostin levels are supposed to give a good estimation of the levels of this negative regulator of bone mass within bone. Most studies evaluating total serum sclerostin found different levels in males compared to females and in older compared to younger subjects. Besides an ELISA detecting total sclerostin an ELISA determining bioactive sclerostin has been developed. The aim of this study was to investigate serum levels of bioactive sclerostin in an Austrian population-based cohort. Methods We conducted a cross-sectional observational study in 235 healthy subjects. Using the bioactive ELISA assay (Biomedica) bioactive sclerostin levels were evaluated. Results Serum levels of bioactive sclerostin were higher in men than in women (24%). The levels correlated positively with age (r = 0.47). A positive correlation could also be detected with body mass index and bone mineral density. Conclusion Using the ELISA detecting bioactive sclerostin our results are consistent with data in the literature obtained by different sclerostin assays. The determination of sclerostin concentrations in peripheral blood thus appears to be a robust parameter of bone metabolism.

scholarly journals Scarcity of scale-free topology is universal across biochemical networks

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Harrison B. Smith ◽  
Hyunju Kim ◽  
Sara I. Walker
Keyword(s):  
Large Body ◽  
Biochemical Networks ◽  
Biological Organization ◽  
Scale Free ◽  
Levels Of Organization ◽  
Common Structure ◽  
Domains Of Life ◽  
Ecosystem Level ◽  
Different Levels ◽  
Organizing Principles

AbstractBiochemical reactions underlie the functioning of all life. Like many examples of biology or technology, the complex set of interactions among molecules within cells and ecosystems poses a challenge for quantification within simple mathematical objects. A large body of research has indicated many real-world biological and technological systems, including biochemistry, can be described by power-law relationships between the numbers of nodes and edges, often described as “scale-free”. Recently, new statistical analyses have revealed true scale-free networks are rare. We provide a first application of these methods to data sampled from across two distinct levels of biological organization: individuals and ecosystems. We analyze a large ensemble of biochemical networks including networks generated from data of 785 metagenomes and 1082 genomes (sampled from the three domains of life). The results confirm no more than a few biochemical networks are any more than super-weakly scale-free. Additionally, we test the distinguishability of individual and ecosystem-level biochemical networks and show there is no sharp transition in the structure of biochemical networks across these levels of organization moving from individuals to ecosystems. This result holds across different network projections. Our results indicate that while biochemical networks are not scale-free, they nonetheless exhibit common structure across different levels of organization, independent of the projection chosen, suggestive of shared organizing principles across all biochemical networks.

scholarly journals Methods in field chronobiology

2017 ◽  
Vol 372 (1734) ◽  
pp. 20160247 ◽  
Author(s):  
Davide M. Dominoni ◽  
Susanne Åkesson ◽  
Raymond Klaassen ◽  
Kamiel Spoelstra ◽  
Martin Bulla
Keyword(s):  
Technological Development ◽  
Monitoring Systems ◽  
Migratory Restlessness ◽  
Biological Organization ◽  
Rapid Improvement ◽  
Free Living ◽  
The Future ◽  
In The Wild ◽  
Temporal Aspect ◽  
Different Levels

Chronobiological research has seen a continuous development of novel approaches and techniques to measure rhythmicity at different levels of biological organization from locomotor activity (e.g. migratory restlessness) to physiology (e.g. temperature and hormone rhythms, and relatively recently also in genes, proteins and metabolites). However, the methodological advancements in this field have been mostly and sometimes exclusively used only in indoor laboratory settings. In parallel, there has been an unprecedented and rapid improvement in our ability to track animals and their behaviour in the wild. However, while the spatial analysis of tracking data is widespread, its temporal aspect is largely unexplored. Here, we review the tools that are available or have potential to record rhythms in the wild animals with emphasis on currently overlooked approaches and monitoring systems. We then demonstrate, in three question-driven case studies, how the integration of traditional and newer approaches can help answer novel chronobiological questions in free-living animals. Finally, we highlight unresolved issues in field chronobiology that may benefit from technological development in the future. As most of the studies in the field are descriptive, the future challenge lies in applying the diverse technologies to experimental set-ups in the wild. This article is part of the themed issue ‘Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals’.

scholarly journals Evolution in the cold

2000 ◽  
Vol 12 (3) ◽  
pp. 257-257 ◽  
Author(s):  
Andrew Clarke
Keyword(s):  
Evolutionary Biology ◽  
Antarctic Fish ◽  
The Arctic ◽  
Polar Regions ◽  
Evolutionary Studies ◽  
Adaptive Radiations ◽  
The Antarctic ◽  
The Impact ◽  
Insight Into

Theodosius Dobzhansky once remarked that nothing in biology makes sense other than in the light of evolution, thereby emphasising the central role of evolutionary studies in providing the theoretical context for all of biology. It is perhaps surprising then that evolutionary biology has played such a small role to date in Antarctic science. This is particularly so when it is recognised that the polar regions provide us with an unrivalled laboratory within which to undertake evolutionary studies. The Antarctic exhibits one of the classic examples of a resistance adaptation (antifreeze peptides and glycopeptides, first described from Antarctic fish), and provides textbook examples of adaptive radiations (for example amphipod crustaceans and notothenioid fish). The land is still largely in the grip of major glaciation, and the once rich terrestrial floras and faunas of Cenozoic Gondwana are now highly depauperate and confined to relatively small patches of habitat, often extremely isolated from other such patches. Unlike the Arctic, where organisms are returning to newly deglaciated land from refugia on the continental landmasses to the south, recolonization of Antarctica has had to take place by the dispersal of propagules over vast distances. Antarctica thus offers an insight into the evolutionary responses of terrestrial floras and faunas to extreme climatic change unrivalled in the world. The sea forms a strong contrast to the land in that here the impact of climate appears to have been less severe, at least in as much as few elements of the fauna show convincing signs of having been completely eradicated.

scholarly journals Associations of weather fronts with pig reproduction and mortality

2021 ◽  
Author(s):  
Tamás Reibling ◽  
Linnea Hagstrand ◽  
Ákos Maróti-Agóts ◽  
Zoltán Barcza ◽  
Norbert Solymosi
Keyword(s):  
Scientific Literature ◽  
Cold Front ◽  
Animal Health ◽  
Population Based ◽  
Temperature Decrease ◽  
Atmospheric Front ◽  
Quantitative Studies ◽  
Warm Front ◽  
The Impact ◽  
Weather Fronts

ABSTRACTFarmers and practising veterinarians have long suspected the impact of weather fronts on production and animal health. A common impression is that sows will farrow earlier in connection with a cold front. There might be a correlation between daily mortality and the occurrence of a strong atmospheric front. Population-based quantitative studies on weather fronts’ effects on animal health and production are very sparse in the scientific literature. In this study, the associations between the weather fronts and daily farrowing incidence, the pregnancy length and the daily death incidence were analysed. The results show that cold front increased the odds of more than daily six farrowings on the day of the front (with at least 3°C cooling OR: 4.79, 95%CI: 1.08-21.21, p=0.039). On the day of the front, with at least 3°C temperature change both the cold and the warm front increased the odds of the farrowing on the day ≥ 118th day of the gestation (OR: 3.10, 95%CI: 1.04-9.30, p=0.43 and OR: 4.39, 95%CI: 1.73-11.15, p=0.002, respectively). On the day after the day of front, the odds of farrowing on the ≤ 113th day of gestation are increased, if the temperature decrease was at least 2°C the OR: 2.30 (95%CI: 1.04-5.06, p=0.039). On the day after the warm front with at least 1°C temperature increase the odds of more than daily three deaths is increased (OR: 5.44, 95%CI: 1.23-24.05, p=0.025).

Developmental biology and human evolution

2011 ◽  
Vol 1 (1) ◽  
pp. e2
Author(s):  
Jeffrey H. Schwartz
Keyword(s):  
Biological Sciences ◽  
Population Genetics ◽  
Evolutionary Biology ◽  
Molecular Change ◽  
Human Fossil ◽  
Evolutionary Studies ◽  
History Of ◽  
Modern Evolutionary Synthesis ◽  
Organismal Development ◽  
Taxic Diversity

The Evolutionary or Modern Evolutionary Synthesis (here identified as the Synthesis) has been portrayed as providing the foundation for uniting a supposed disarray of biological disciplines through the lens of Darwinism fused with population genetics. Rarely acknowledged is that the Synthesis’s success was also largely due to its architects’ effectiveness in submerging British and German attempts at a synthesis by uniting the biological sciences through shared evolutionary concerns. Dobzhansky and Mayr imposed their bias toward population genetics, population (as supposedly opposed to typological) thinking, and Morgan’s conception of specific genes for specific features (here abbreviated as genes for) on human evolutionary studies. Dobzhansky declared that culture buffered humans from the whims of selection. Mayr argued that as variable as humans are now, their extinct relatives were even more variable; thus the human fossil did not present taxic diversity and all known fossils could be assembled into a gradually changing lineage of time-successive species. When Washburn centralized these biases in the new physical anthropology the fate of paleoanthropology as a non-contributor to evolutionary theory was sealed. Molecular anthropology followed suit in embracing Zuckerkandl and Pauling’s assumption that molecular change was gradual and perhaps more importantly continual. Lost in translation was and still is an appreciation of organismal development. Here I will summarize the history of these ideas and their alternatives in order to demonstrate assumptions that still need to be addressed before human evolutionary studies can more fully participate in what is a paradigm shift-in-the-making in evolutionary biology.

scholarly journals Cancer and intercellular cooperation

2017 ◽  
Vol 4 (10) ◽  
pp. 170470 ◽  
Author(s):  
Marta Bertolaso ◽  
Anna Maria Dieli
Keyword(s):  
Natural Selection ◽  
Evolutionary Biology ◽  
Darwinian Evolution ◽  
Individual Organism ◽  
Major Transitions ◽  
Somatic Evolution ◽  
Selection Processes ◽  
Intercellular Cooperation ◽  
Multicellular Organisms ◽  
Different Levels

The major transitions approach in evolutionary biology has shown that the intercellular cooperation that characterizes multicellular organisms would never have emerged without some kind of multilevel selection. Relying on this view, the Evolutionary Somatic view of cancer considers cancer as a breakdown of intercellular cooperation and as a loss of the balance between selection processes that take place at different levels of organization (particularly single cell and individual organism). This seems an elegant unifying framework for healthy organism, carcinogenesis, tumour proliferation, metastasis and other phenomena such as ageing. However, the gene-centric version of Darwinian evolution, which is often adopted in cancer research, runs into empirical problems: proto-tumoural and tumoural features in precancerous cells that would undergo ‘natural selection’ have proved hard to demonstrate; cells are radically context-dependent, and some stages of cancer are poorly related to genetic change. Recent perspectives propose that breakdown of intercellular cooperation could depend on ‘fields’ and other higher-level phenomena, and could be even mutations independent. Indeed, the field would be the context, allowing (or preventing) genetic mutations to undergo an intra-organism process analogous to natural selection. The complexities surrounding somatic evolution call for integration between multiple incomplete frameworks for interpreting intercellular cooperation and its pathologies.

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