The Use of Canalized Characters to Specify the Limits of Ecological Niches

1977 ◽  
Vol 111 (977) ◽  
pp. 196-198 ◽  
Author(s):  
Alex Fraser
Keyword(s):  
Ecological Niches

Pollen morphology of some Tamarix (Tamaricaceae) species of Iran

2020 ◽  
Vol 62 (1-2) ◽  
pp. 151-161
Author(s):  
T. Shagholi ◽  
M. Keshavarzi ◽  
M. Sheidai
Keyword(s):  
North Africa ◽  
Pollen Grains ◽  
Ecological Niches ◽  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
Qualitative And Quantitative ◽  
Petal Length ◽  
Electron Microscopes ◽  
High Level ◽  
Scanning Electron Microscopes

Tamarix L. (Tamaricaceae) is a halophytic shrub in different parts of Asia and North Africa. Taxonomy and species limitation of Tamarix is very complex. This genus has three sections as Tamarix, Oligadenia, and Polyadenia, which are mainly separated by petal length, the number of stamens, the shape of androecial disk and attachment of filament on the androecial disk. As there was no palynological data on pollen features of Tamarix species of Iran, in the present study 12 qualitative and quantitative pollen features were evaluated to find diagnostic ones. Pollen grains of 8 Tamarix species were collected from nature. Pollen grains were studied without any treatment. Measurements were based on at least 50 pollen grains per specimen. Light and scanning electron microscopes were used. Multivariate statistical methods were applied to clarify the species relationships based on pollen data. All species studied showed monad and tricolpate (except some individuals of T. androssowii). Some Tamarix species show a high level of variability, in response to ecological niches and phenotypic plasticity, which make Tamarix species separation much more difficult. Based on the results of the present study, pollen grains features are not in agreement with previous morphological and molecular genetics about the sectional distinction.

STRUCTURE AND DYNAMICS OF ENVIRONMENTAL PARAMETERS OF HUMAN INTESTINAL MICROBIOME IN DIFFERENT CLIMATIC AND ECOLOGICAL ZONES OF ST. PETERSBURG

2020 ◽  
pp. 31-36
Author(s):  
Bugero N.V. ◽  
Ilyina N.A. ◽  
Aleksandrova S.M.
Keyword(s):  
Environmental Parameters ◽  
Intestinal Microbiome ◽  
Ecological Niches ◽  
Horizontal Structure ◽  
Ecological Zones ◽  
Qualitative And Quantitative ◽  
Symbiotic Relationships ◽  
Structure And Dynamics ◽  
Quantitative Changes ◽  
Micro Organisms

In order to understand the structure and dynamics of symbiotic relationships of human intestinal biotope micro-organisms, taxonomic constancy indices, the degree of contagion of the biocenosis under study and floristic significance were investigated, which made it possible to detect qualitative and quantitative changes in the microecology of the biotope being studied in persons living in different ecologically heterogeneous territories of Saint Petersburg. The contagiosity index estimated the distribution of species in space. Persons living in the ecologically disadvantaged Kirov district of the city have been found to show a reliable increase in this indicator for the obligate microflora: bifido and lacto bacteria, intestinal columns and bacteroids, compared to the resort district, which is considered a relatively favourable area for residence. On the contrary, there has been a reliable decrease in this indicator in the group of opportunistic micro-organisms (fungi of the genus Candida, staphylococcus, clostridium, etc.), resulting in the liberation of ecological niches successfully occupied by transient flora. This ratio reveals an imbalance of participation in the horizontal structure of the intestine ecosystem of the main symbiotes and representatives of the transient flora. To analyse the structure of symbiotic relationships, the constancy indices that form the microflora of the individuals of the groups studied were investigated. The analysis of the data obtained suggested that the dominant species in both groups were optional-anaerobic bifido and lactobacteria and oblique-anaerobic bacteroids. It should be noted, however, that in the residents of the dysfunctional Kirovsky district, against the background of the reduced constancy of the normal flora, opportunistic micro-organisms have entered. The floral significance index was also declining in the obligate flora of this group and increased for opportunistic species. Thus, the study of the environmental characteristics of the intestinal biotope using different ecological parameters for persons living in different technogenic load regions of St. Petersburg has shown that in the Kirov district with an unfavourable environmental situation there are compensated qualitative and quantitative changes in the intestinal microbiocenosis, resulting in a change in the hierarchy in the overall structure of micro-organisms.

scholarly journals From tree to architecture: how functional morphology of arborescence connects plant biology, evolution and physics

2021 ◽  
Author(s):  
Anita Roth-Nebelsick ◽  
Tatiana Miranda ◽  
Martin Ebner ◽  
Wilfried Konrad ◽  
Christopher Traiser
Keyword(s):  
Land Plant ◽  
Plant Evolution ◽  
Ecological Niches ◽  
Long Distance ◽  
Ongoing Research ◽  
Long Distance Transport ◽  
Theoretical Approaches ◽  
Trade Offs ◽  
Interfacial Physics ◽  
Plant Water Transport

AbstractTrees are the fundamental element of forest ecosystems, made possible by their mechanical qualities and their highly sophisticated conductive tissues. The evolution of trees, and thereby the evolution of forests, were ecologically transformative and affected climate and biogeochemical cycles fundamentally. Trees also offer a substantial amount of ecological niches for other organisms, such as epiphytes, creating a vast amount of habitats. During land plant evolution, a variety of different tree constructions evolved and their constructional principles are a subject of ongoing research. Understanding the “natural construction” of trees benefits strongly from methods and approaches from physics and engineering. Plant water transport is a good example for the ongoing demand for interdisciplinary efforts to unravel form-function relationships on vastly differing scales. Identification of the unique mechanism of water long-distance transport requires a solid basis of interfacial physics and thermodynamics. Studying tree functions by using theoretical approaches is, however, not a one-sided affair: The complex interrelationships between traits, functionality, trade-offs and phylogeny inspire engineers, physicists and architects until today.

scholarly journals Unlocking the Patterns of the Tunisian Durum Wheat Landraces Genetic Structure Based on Phenotypic Characterization in Relation to Farmer’s Vernacular Name

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 634
Author(s):  
Cyrine Robbana ◽  
Zakaria Kehel ◽  
Karim Ammar ◽  
Carlos Guzmán ◽  
M’Barek Ben Naceur ◽  
...  
Keyword(s):  
Genetic Structure ◽  
Durum Wheat ◽  
Smallholder Farmers ◽  
Phenotypic Variability ◽  
Phenotypic Characterization ◽  
Ecological Niches ◽  
Dry Conditions ◽  
New Gene ◽  
Wheat Landraces ◽  
Durum Wheat Landraces

During the 1970s, Tunisian durum wheat landraces were replaced progressively by modern cultivars. These landraces are nowadays maintained by smallholder farmers in some ecological niches and are threatened gradually by extinction resulting in the narrowing of the genetic diversity. This study aims to investigate patterns of phenotypic variability using twelve quantitative traits in a panel of 189 durum wheat landraces and seven checks, based on farmer’s population name attribution and genetic structure. Our results showed high phenotypic variability among and within landraces and checks for ten out of twelve studied traits. The principal components analysis showed similar grouping using farmers name attribution and genetic structure using K = 6. These results confirmed the identification of a new gene pool in the oases of Tunisia, represented by the sub-population Jenah Zarzoura and the robustness and high relationships between phenotypic and genome-wide genetic structure using DArTseq method. These findings will enhance the conservation efforts of these landraces and their use in breeding efforts at national and international levels to adapt to dry conditions.

scholarly journals Thermal reaction norms of key metabolic enzymes reflect divergent physiological and behavioral adaptations of closely related amphipod species

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lena Jakob ◽  
Kseniya P. Vereshchagina ◽  
Anette Tillmann ◽  
Lorena Rivarola-Duarte ◽  
Denis V. Axenov-Gribanov ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Lake Baikal ◽  
Enzyme Activities ◽  
Large Scale ◽  
Metabolic Enzymes ◽  
Thermal Reaction ◽  
Reaction Norms ◽  
Ecological Niches ◽  
Amphipod Species ◽  
Thermal Plasticity

AbstractLake Baikal is inhabited by more than 300 endemic amphipod species, which are narrowly adapted to certain thermal niches due to the high interspecific competition. In contrast, the surrounding freshwater fauna is commonly represented by species with large-scale distribution and high phenotypic thermal plasticity. Here, we investigated the thermal plasticity of the energy metabolism in two closely-related endemic amphipod species from Lake Baikal (Eulimnogammarus verrucosus; stenothermal and Eulimnogammarus cyaneus; eurythermal) and the ubiquitous Holarctic amphipod Gammarus lacustris (eurythermal) by exposure to a summer warming scenario (6–23.6 °C; 0.8 °C d−1). In concert with routine metabolic rates, activities of key metabolic enzymes increased strongly with temperature up to 15 °C in E. verrucosus, whereupon they leveled off (except for lactate dehydrogenase). In contrast, exponential increases were seen in E. cyaneus and G. lacustris throughout the thermal trial (Q10-values: 1.6–3.7). Cytochrome-c-oxidase, lactate dehydrogenase, and 3-hydroxyacyl-CoA dehydrogenase activities were found to be higher in G. lacustris than in E. cyaneus, especially at the highest experimental temperature (23.6 °C). Decreasing gene expression levels revealed some thermal compensation in E. cyaneus but not in G. lacustris. In all species, shifts in enzyme activities favored glycolytic energy generation in the warmth. The congruent temperature-dependencies of enzyme activities and routine metabolism in E. verrucosus indicate a strong feedback-regulation of enzymatic activities by whole organism responses. The species-specific thermal reaction norms reflect the different ecological niches, including the spatial distribution, distinct thermal behavior such as temperature-dependent migration, movement activity, and mating season.

scholarly journals The evolution of episodic-like memory: the importance of biological and ecological constraints

2021 ◽  
Vol 36 (2) ◽  
Author(s):  
Bas van Woerkum
Keyword(s):  
Episodic Memory ◽  
Perceptual Learning ◽  
Alternative Explanation ◽  
Past Experience ◽  
Ecological Niches ◽  
Insufficient Information ◽  
Ecological Constraints ◽  
Animal Minds ◽  
Learning Abilities ◽  
Nonhuman Animals

AbstractA persisting question in the philosophy of animal minds is which nonhuman animals share our capacity for episodic memory (EM). Many authors address this question by primarily defining EM, trying to capture its seemingly unconstrained flexibility and independence from environmental and bodily constraints. EM is therefore often opposed to clearly context-bound capacities like tracking environmental regularities and forming associations. The problem is that conceptualizing EM in humans first, and then reconstructing how humans evolved this capacity, provides little constraints for understanding the evolution of memory abilities in other species: it defines “genuine” EM as independent from animals’ evolved sensorimotor setup and learning abilities. In this paper, I define memory in terms of perceptual learning: remembering means “knowing (better) what to do in later situations because of past experience in similar earlier situations”. After that, I explain how episodic memory can likewise be explained in terms of perceptual learning. For this, we should consider that the information in animals’ ecological niches is much richer than has hitherto been presumed. Accordingly, instead of asking “given that environmental stimuli provide insufficient information about the cache, what kind of representation does the jay need?” we ask “given that the animal performs in this way, what kind of information is available in the environment?” My aim is not to give a complete alternative explanation of EM; rather, it is to provide conceptual and methodological tools for more zoocentric comparative EM-research.

Habitat use and the coexistence of the sika deer and the Japanese serow, sympatric ungulates from Mt. Asama, central Japan

Mammalia ◽  
2020 ◽  
Vol 84 (6) ◽  
pp. 503-511
Author(s):  
Hayato Takada ◽  
Riki Ohuchi ◽  
Haruko Watanabe ◽  
Risako Yano ◽  
Risako Miyaoka ◽  
...  
Keyword(s):  
Habitat Use ◽  
Sika Deer ◽  
Cervus Nippon ◽  
Niche Differentiation ◽  
Ecological Niches ◽  
Dwarf Bamboo ◽  
Central Japan ◽  
Habitat Mosaic ◽  
The Japanese Archipelago ◽  
Japanese Serow

AbstractDifferential resource use allows for diverse species to specialize in ecological niches and thus coexist in a particular area. In the Japanese archipelago, increasing sika deer (Cervus nippon, Temminck 1836) densities have excluded the Japanese serow (Capricornis crispus, Temminck 1836), but in places where deer population densities are low, the two species coexist. We wanted to better understand their habitats and how these two ungulates manage to coexist. We evaluated the role of habitat use in the coexistence of these two sympatric ungulates on Mt. Asama, central Japan. Deer frequently used the dwarf bamboo-rich communities in autumn and winter, and their habitat use was not associated with topography. Serows frequently used deciduous broadleaf shrub-rich communities and steep slopes throughout the year. Consequently, their habitat use was significantly different in terms of vegetation and topography. Niche breadth suggests that deer tend to be generalists, whereas serows tend to be specialists. Niche differentiation in habitat use between deer and serows may make the coexistence of these similarly sized ungulates possible in Japanese mountainous zones. Therefore, the fine-grained habitat mosaic of different vegetation and topography areas might be the underlying feature that allows the coexistence of these two species.

scholarly journals Microbiomes attached to fresh perennial ryegrass are temporally resilient and adapt to changing ecological niches

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sharon A. Huws ◽  
Joan E. Edwards ◽  
Wanchang Lin ◽  
Francesco Rubino ◽  
Mark Alston ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Perennial Ryegrass ◽  
Transcriptional Activity ◽  
Ecological Niches ◽  
Ecological Interactions ◽  
Carbohydrate Degradation ◽  
Host Nutrition ◽  
Role Based ◽  
Insight Into

Abstract Background Gut microbiomes, such as the rumen, greatly influence host nutrition due to their feed energy-harvesting capacity. We investigated temporal ecological interactions facilitating energy harvesting at the fresh perennial ryegrass (PRG)-biofilm interface in the rumen using an in sacco approach and prokaryotic metatranscriptomic profiling. Results Network analysis identified two distinct sub-microbiomes primarily representing primary (≤ 4 h) and secondary (≥ 4 h) colonisation phases and the most transcriptionally active bacterial families (i.e Fibrobacteriaceae, Selemondaceae and Methanobacteriaceae) did not interact with either sub-microbiome, indicating non-cooperative behaviour. Conversely, Prevotellaceae had most transcriptional activity within the primary sub-microbiome (focussed on protein metabolism) and Lachnospiraceae within the secondary sub-microbiome (focussed on carbohydrate degradation). Putative keystone taxa, with low transcriptional activity, were identified within both sub-microbiomes, highlighting the important synergistic role of minor bacterial families; however, we hypothesise that they may be ‘cheating’ in order to capitalise on the energy-harvesting capacity of other microbes. In terms of chemical cues underlying transition from primary to secondary colonisation phases, we suggest that AI-2-based quorum sensing plays a role, based on LuxS gene expression data, coupled with changes in PRG chemistry. Conclusions In summary, we show that fresh PRG-attached prokaryotes are resilient and adapt quickly to changing niches. This study provides the first major insight into the complex temporal ecological interactions occurring at the plant-biofilm interface within the rumen. The study also provides valuable insights into potential plant breeding strategies for development of the utopian plant, allowing optimal sustainable production of ruminants.

scholarly journals Defining the niche for niche construction: evolutionary and ecological niches

2021 ◽  
Vol 36 (3) ◽  
Author(s):  
Rose Trappes
Keyword(s):  
Evolutionary Biology ◽  
Ecological Niche ◽  
Niche Construction ◽  
Habitat Degradation ◽  
Ecological Niches ◽  
Niche Concept ◽  
Definition Of ◽  
Compare And Contrast ◽  
Extreme Habitat

AbstractNiche construction theory (NCT) aims to transform and unite evolutionary biology and ecology. Much of the debate about NCT has focused on construction. Less attention has been accorded to the niche: what is it, exactly, that organisms are constructing? In this paper I compare and contrast the definition of the niche used in NCT with ecological niche definitions. NCT’s concept of the evolutionary niche is defined as the sum of selection pressures affecting a population. So defined, the evolutionary niche is narrower than the ecological niche. Moreover, when contrasted with a more restricted ecological niche concept, it has a slightly different extension. I point out three kinds of cases in which the evolutionary niche does not coincide with realized ecological niches: extreme habitat degradation, commensalism, and non-limiting or super-abundant resources. These conceptual differences affect the role of NCT in unifying ecology and evolutionary biology.

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