scholarly journals Evolutionary relatedness does not predict competition and co-occurrence in natural or experimental communities of green algae

2015 ◽  
Vol 282 (1799) ◽  
pp. 20141745 ◽  
Author(s):  
Markos A. Alexandrou ◽  
Bradley J. Cardinale ◽  
John D. Hall ◽  
Charles F. Delwiche ◽  
Keith Fritschie ◽  
...  
Keyword(s):  
Green Algae ◽  
Species Interactions ◽  
Laboratory Experiments ◽  
Evolutionary Relationships ◽  
Biological Traits ◽  
Phylogenetic Distance ◽  
Ecological Data ◽  
Experimental Systems ◽  
Evolutionary Relatedness ◽  
Close Relatives

The competition-relatedness hypothesis (CRH) predicts that the strength of competition is the strongest among closely related species and decreases as species become less related. This hypothesis is based on the assumption that common ancestry causes close relatives to share biological traits that lead to greater ecological similarity. Although intuitively appealing, the extent to which phylogeny can predict competition and co-occurrence among species has only recently been rigorously tested, with mixed results. When studies have failed to support the CRH, critics have pointed out at least three limitations: (i) the use of data poor phylogenies that provide inaccurate estimates of species relatedness, (ii) the use of inappropriate statistical models that fail to detect relationships between relatedness and species interactions amidst nonlinearities and heteroskedastic variances, and (iii) overly simplified laboratory conditions that fail to allow eco-evolutionary relationships to emerge. Here, we address these limitations and find they do not explain why evolutionary relatedness fails to predict the strength of species interactions or probabilities of coexistence among freshwater green algae. First, we construct a new data-rich, transcriptome-based phylogeny of common freshwater green algae that are commonly cultured and used for laboratory experiments. Using this new phylogeny, we re-analyse ecological data from three previously published laboratory experiments. After accounting for the possibility of nonlinearities and heterogeneity of variances across levels of relatedness, we find no relationship between phylogenetic distance and ecological traits. In addition, we show that communities of North American green algae are randomly composed with respect to their evolutionary relationships in 99% of 1077 lakes spanning the continental United States. Together, these analyses result in one of the most comprehensive case studies of how evolutionary history influences species interactions and community assembly in both natural and experimental systems. Our results challenge the generality of the CRH and suggest it may be time to re-evaluate the validity and assumptions of this hypothesis.

scholarly journals Mechatronics: Experiential Learning and the Stimulation of Thinking Skills

2021 ◽  
Vol 11 (2) ◽  
pp. 46
Author(s):  
Maki K. Habib ◽  
Fusaomi Nagata ◽  
Keigo Watanabe
Keyword(s):  
Critical Thinking ◽  
Experiential Learning ◽  
Learning Process ◽  
Laboratory Experiments ◽  
Thinking Skills ◽  
Project Based Learning ◽  
Critical Thinking Skills ◽  
Learning Approach ◽  
Learning Approaches ◽  
Experimental Systems

The development of experiential learning methodologies is gaining attention, due to its contributions to enhancing education quality. It focuses on developing competencies, and build-up added values, such as creative and critical thinking skills, with the aim of improving the quality of learning. The interdisciplinary mechatronics field accommodates a coherent interactive concurrent design process that facilitates innovation and develops the desired skills by adopting experiential learning approaches. This educational learning process is motivated by implementation, assessment, and reflections. This requires synergizing cognition, perception, and behavior with experience sharing and evaluation. Furthermore, it is supported by knowledge accumulation. The learning process with active student’s engagement (participation and investigation) is integrated with experimental systems that are developed to facilitate experiential learning supported by properly designed lectures, laboratory experiments, and integrated with course projects. This paper aims to enhance education, learning quality, and contribute to the learning process, while stimulating creative and critical thinking skills. The paper has adopted a student-centered learning approach and focuses on developing training tools to improve the hands-on experience and integrate it with project-based learning. The developed experimental systems have their learning indicators where students acquire knowledge and learn the target skills through involvement in the process. This is inspired by collaborative knowledge sharing, brainstorming, and interactive discussions. The learning outcomes from lectures and laboratory experiments are synergized with the project-based learning approach to yield the desired promising results and exhibit the value of learning. The effectiveness of the developed experimental systems along with the adopted project-based learning approach is demonstrated and evaluated during laboratory sessions supporting different courses at Sanyo-Onoda City University, Yamaguchi, Japan, and at the American University in Cairo.

scholarly journals Inhibition or Facilitation? Contrasted Inter-Specific Interactions in Sphagnum under Laboratory and Field Conditions

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1554
Author(s):  
Chao Liu ◽  
Zhao-Jun Bu ◽  
Azim Mallik ◽  
Yong-Da Chen ◽  
Xue-Feng Hu ◽  
...  
Keyword(s):  
Field Experiment ◽  
Species Interactions ◽  
Laboratory Experiments ◽  
Resource Competition ◽  
Specific Interactions ◽  
Interaction Type ◽  
Negative Effects ◽  
Experiment Data ◽  
The Stability ◽  
Positive Effect

In a natural environment, plants usually interact with their neighbors predominantly through resource competition, allelopathy, and facilitation. The occurrence of the positive effect of allelopathy between peat mosses (Sphagnum L.) is rare, but it has been observed in a field experiment. It is unclear whether the stability of the water table level in peat induces positive vs. negative effects of allelopathy and how that is related to phenolic allelochemical production in Sphagnum. Based on field experiment data, we established a laboratory experiment with three neighborhood treatments to measure inter-specific interactions between Sphagnum angustifolium (Russ.) C. Jens and Sphagnum magellanicum Brid. We found that the two species were strongly suppressed by the allelopathic effects of each other. S. magellanicum allelopathically facilitated S. angustifolium in the field but inhibited it in the laboratory, and relative allelopathy intensity appeared to be positively related to the content of released phenolics. We conclude that the interaction type and intensity between plants are dependent on environmental conditions. The concentration of phenolics alone may not explain the type and relative intensity of allelopathy. Carefully designed combined field and laboratory experiments are necessary to reveal the mechanism of species interactions in natural communities.

scholarly journals Evolutionary relationships of completely sequenced Clostridia species and close relatives

2015 ◽  
Vol 65 (Pt_11) ◽  
pp. 4276-4283 ◽  
Author(s):  
Takashi Kunisawa
Keyword(s):  
Maximum Likelihood ◽  
Phylogenetic Trees ◽  
Gene Arrangement ◽  
Evolutionary Relationships ◽  
Rrna Gene ◽  
Sequence Information ◽  
Bayesian Tree ◽  
Maximum Likelihood Methods ◽  
Genome Sequence Information ◽  
Close Relatives

The class Clostridia in the phylum Firmicutes includes a very heterogeneous assemblage of bacteria. Their evolutionary relationships are not well established; revisions of their phylogenetic placements based on comparative studies of 16S rRNA gene sequences are in progress as genome sequence information accumulates. In this work, phylogenetic trees were reconstructed based on 21 concatenated ribosomal protein sequences using Bayesian and maximum-likelihood methods. Both trees consistently indicate that the Halanaerobiales is a deeply branching order among the class Clostridia. The rest of the Clostridia species are grouped into 10 monophyletic clusters, most of which are comprised of two or three orders and families according to the current Clostridial taxonomy. The maximum-likelihood tree placed Coprothermobacter proteolyticus and Thermodesulfobium narugense in the class Clostridia in accordance with the current taxonomy, in which these two bacteria are assigned to the family Thermodesulfobiaceae. However, the Bayesian tree placed these two bacteria at the boundary between the Firmicutes and Actinobacteria. A gene arrangement that is present uniquely in the Firmicutes species was identified. Both Coprothermobacter proteolyticus and Thermodesulfobium narugense do not have this arrangement characteristic of the Firmicutes. On the basis of the Bayesian tree and gene arrangement comparison, it is suggested that Coprothermobacter proteolyticus and Thermodesulfobium narugense should be placed outside the phylum Firmicutes.

scholarly journals Metabolic Symbiosis Facilitates Species Coexistence and Generates Light-Dependent Priority Effects

2021 ◽  
Vol 8 ◽  
Author(s):  
Veronica Hsu ◽  
Holly V. Moeller
Keyword(s):  
Carbon Source ◽  
Community Composition ◽  
Green Algae ◽  
Species Interactions ◽  
Species Coexistence ◽  
Priority Effects ◽  
Competitive Interactions ◽  
Paramecium Bursaria ◽  
Mutual Benefit ◽  
Cascading Effects

Metabolic symbiosis is a form of symbiosis in which organisms exchange metabolites, typically for mutual benefit. For example, acquired phototrophs like Paramecium bursaria obtain photosynthate from endosymbiotic green algae called Chlorella. In addition to facilitating the persistence of P. bursaria by providing a carbon source that supplements P. bursaria’s heterotrophic digestion of bacteria, symbiotic Chlorella may impact competitive interactions between P. bursaria and other bacterivores, with cascading effects on community composition and overall diversity. Here, we tested the effects of metabolic symbiosis on coexistence by assessing the impacts of acquired phototrophy on priority effects, or the effect of species arrival order on species interactions, between P. bursaria and its competitor Colpidium. Our results suggest light-dependent priority effects. The acquired phototroph benefited from metabolic symbiosis during sequential arrival of each organism in competition, and led to increased growth of late-arriving Colpidium. These findings demonstrate that understanding the consequences of priority effects for species coexistence requires consideration of metabolic symbiosis.

scholarly journals Comparative Analyses of Vertebrate Gut Microbiomes Reveal Convergence between Birds and Bats

mBio ◽  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Se Jin Song ◽  
Jon G. Sanders ◽  
Frédéric Delsuc ◽  
Jessica Metcalf ◽  
Katherine Amato ◽  
...  
Keyword(s):  
Gut Microbiome ◽  
Cost Benefit ◽  
Phylogenetic Distance ◽  
Strong Correlations ◽  
Evolutionary Relatedness ◽  
Host Diet ◽  
Comprehensive Survey ◽  
Taxonomic Range ◽  
Host Phylogeny ◽  
The Cost

ABSTRACT Diet and host phylogeny drive the taxonomic and functional contents of the gut microbiome in mammals, yet it is unknown whether these patterns hold across all vertebrate lineages. Here, we assessed gut microbiomes from ∼900 vertebrate species, including 315 mammals and 491 birds, assessing contributions of diet, phylogeny, and physiology to structuring gut microbiomes. In most nonflying mammals, strong correlations exist between microbial community similarity, host diet, and host phylogenetic distance up to the host order level. In birds, by contrast, gut microbiomes are only very weakly correlated to diet or host phylogeny. Furthermore, while most microbes resident in mammalian guts are present in only a restricted taxonomic range of hosts, most microbes recovered from birds show little evidence of host specificity. Notably, among the mammals, bats host especially bird-like gut microbiomes, with little evidence for correlation to host diet or phylogeny. This suggests that host-gut microbiome phylosymbiosis depends on factors convergently absent in birds and bats, potentially associated with physiological adaptations to flight. Our findings expose major variations in the behavior of these important symbioses in endothermic vertebrates and may signal fundamental evolutionary shifts in the cost/benefit framework of the gut microbiome. IMPORTANCE In this comprehensive survey of microbiomes of >900 species, including 315 mammals and 491 birds, we find a striking convergence of the microbiomes of birds and animals that fly. In nonflying mammals, diet and short-term evolutionary relatedness drive the microbiome, and many microbial species are specific to a particular kind of mammal, but flying mammals and birds break this pattern with many microbes shared across different species, with little correlation either with diet or with relatedness of the hosts. This finding suggests that adaptation to flight breaks long-held relationships between hosts and their microbes.

SYSTEMATICS AND ENTOMOLOGY: SOME MAJOR THEMES

1993 ◽  
Vol 125 (S165) ◽  
pp. 257-272 ◽  
Author(s):  
H.V. Danks ◽  
George E. Ball
Keyword(s):  
Species Interactions ◽  
Biological Systems ◽  
Biological Traits ◽  
Immature Stages ◽  
Educational Facilities ◽  
Natural Processes ◽  
Terrestrial Arthropods ◽  
The World ◽  
Ecological Roles

AbstractSystematics allows the extraordinary diversity of biological systems to be understood, and information about organisms to be organized and made accessible. Key patterns that help to interpret natural processes can be summarized, and biological traits predicted, by determining the relationships of natural taxa. Ecological roles are made visible and existing knowledge is made accessible only through specific names. Most organismic diversity is represented by terrestrial arthropods, but knowledge is very incomplete. Even for species found in Canada, half have not been described and the immature stages of most are unknown.Systematics supports entomology and underpins studies of biology in many different ways. From these roles, understanding is gained about diversity and evolution, distributions and biogeographically significant regions of the country, adaptations as related especially to species interactions and metamorphosis, and the application of systematics information. In addition, the values of basic systematic work, modern techniques, and long-term coordinated efforts in studying the fauna are emphasized.A coordinated study of diversity by systematists in conjunction with ecologists and others is required. Such a coordinated approach is timely given recent recognition that the world depends on self-sustaining but increasingly threatened biological systems. Diverse organisms maintain those systems but can be distinguished only through systematics. Adequate long-term support — for systematics positions, research collections, activities that include the preparation of basic works such as monographs, and educational facilities — is required to underpin the systematics component of such a coordinated study.

Does evolutionary relatedness predict ecological similarity?

Paleobiology ◽  
2020 ◽  
pp. 1-17
Author(s):  
Judith A. Sclafani ◽  
Curtis R. Congreve ◽  
Mark E. Patzkowsky
Keyword(s):  
Phylogenetic Trees ◽  
Evolutionary Model ◽  
Branch Length ◽  
Pairwise Distance ◽  
Phylogenetic Distance ◽  
Environmental Preferences ◽  
Occurrence Data ◽  
Evolutionary Relatedness ◽  
Species Pairs ◽  
Ecological Difference

Abstract A fundamental question in paleobiology is whether ecology is correlated with evolutionary history. By combining time-calibrated phylogenetic trees with genus occurrence data through time, we can understand how environmental preferences are distributed on a tree and evaluate support for models of ecological similarity. Exploring parameters that lend support to each evolutionary model will help address questions that lie at the nexus of the evolutionary and ecological sciences. We calculated ecological difference and phylogenetic distance between species pairs for 83 taxa used in recent phylogenetic revisions of the brachiopod order Strophomenida. Ecological difference was calculated as the pairwise distance along gradients of water depth, carbonate, and latitudinal affinity. Phylogenetic distance was calculated as the pairwise branch length between tips of the tree. Our results show no relationship between ecological affinity and phylogeny. Instead results suggest an ecological burst during the initial radiation of the clade. This pattern likely reflects scaling at the largest macroevolutionary and macroecological scales preserved in the fossil record. Hierarchical scaling of ecological and evolutionary processes is complex, but phylogenetic paleoecology is an avenue for better evaluating these questions.

scholarly journals Global-level population genomics reveals differential effects of geography and phylogeny on horizontal gene transfer in soil bacteria

2019 ◽  
Vol 116 (30) ◽  
pp. 15200-15209 ◽  
Author(s):  
Alex Greenlon ◽  
Peter L. Chang ◽  
Zehara Mohammed Damtew ◽  
Atsede Muleta ◽  
Noelia Carrasquilla-Garcia ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Population Genomics ◽  
Geographic Distance ◽  
Detectable Effect ◽  
Evolutionary Divergence ◽  
Phylogenetic Distance ◽  
Global Level ◽  
Bacterial Populations ◽  
Representative Subset ◽  
Evolutionary Relatedness

Although microorganisms are known to dominate Earth’s biospheres and drive biogeochemical cycling, little is known about the geographic distributions of microbial populations or the environmental factors that pattern those distributions. We used a global-level hierarchical sampling scheme to comprehensively characterize the evolutionary relationships and distributional limitations of the nitrogen-fixing bacterial symbionts of the crop chickpea, generating 1,027 draft whole-genome sequences at the level of bacterial populations, including 14 high-quality PacBio genomes from a phylogenetically representative subset. We find that diverse Mesorhizobium taxa perform symbiosis with chickpea and have largely overlapping global distributions. However, sampled locations cluster based on the phylogenetic diversity of Mesorhizobium populations, and diversity clusters correspond to edaphic and environmental factors, primarily soil type and latitude. Despite long-standing evolutionary divergence and geographic isolation, the diverse taxa observed to nodulate chickpea share a set of integrative conjugative elements (ICEs) that encode the major functions of the symbiosis. This symbiosis ICE takes 2 forms in the bacterial chromosome—tripartite and monopartite—with tripartite ICEs confined to a broadly distributed superspecies clade. The pairwise evolutionary relatedness of these elements is controlled as much by geographic distance as by the evolutionary relatedness of the background genome. In contrast, diversity in the broader gene content of Mesorhizobium genomes follows a tight linear relationship with core genome phylogenetic distance, with little detectable effect of geography. These results illustrate how geography and demography can operate differentially on the evolution of bacterial genomes and offer useful insights for the development of improved technologies for sustainable agriculture.

The Evolutionary Relationships between Endosymbiotic Green Algae of Paramecium bursaria Syngens Originating from Different Geographical Locations

2016 ◽  
Vol 64 (1) ◽  
pp. 47-54 ◽  
Author(s):  
Patrycja Zagata ◽  
Magdalena Greczek-Stachura ◽  
Sebastian Tarcz ◽  
Maria Rautian
Keyword(s):  
Green Algae ◽  
Paramecium Bursaria ◽  
Evolutionary Relationships ◽  
Geographical Locations

scholarly journals Solving the sex ratio scandal in Melittobia wasps

2020 ◽  
Author(s):  
Jun Abe ◽  
Ryosuke Iritani ◽  
Koji Tsuchida ◽  
Yoshitaka Kamimura ◽  
Stuart A. West
Keyword(s):  
Sex Ratio ◽  
Sex Allocation ◽  
Laboratory Experiments ◽  
Sex Ratios ◽  
Local Mate Competition ◽  
Mate Competition ◽  
Offspring Sex ◽  
Local Mate ◽  
Close Relatives

AbstractThe scandalous sex ratio behaviour of Melittobia wasps has long posed one of the greatest problems for the field of sex allocation. In contrast to the predictions of theory, and the behaviour of numerous other organisms, laboratory experiments have found that Melittobia females do not produce less female-biased offspring sex ratios when more females lay eggs on a patch. We resolve this scandal, by showing that, in nature, females of M. australica have sophisticated sex ratio behaviour, where their strategy also depends upon whether they have dispersed from the patch where they emerged. When females have not dispersed, they will be laying eggs with close relatives, which keeps local mate competition high, even with multiple females, and so they are selected to produce consistently female-biased sex ratios. Laboratory experiments mimic these conditions. In contrast, when females disperse, they will be interacting with non-relatives, and so they adjust their sex ratio depending upon the number of females laying eggs. Consequently, females appear to use dispersal status as an indirect cue of relatedness, and whether they should adjust their sex ratio in response to the number of females laying eggs on the patch.

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