Unifying Ecological and Evolutionary Dynamics Through Experimental Stochastic Demography

2009 ◽  
Vol 55 (3) ◽  
pp. 199-205 ◽  
Author(s):  
Isabel M. Smallegange ◽  
Tim Coulson
Keyword(s):  
Evolutionary Dynamics ◽  
Evolutionary Ecology ◽  
Death Rates ◽  
Stochastic Environments ◽  
Push Forward ◽  
Demographic Methods ◽  
Stochastic Demography

Ecological and evolutionary dynamics depend upon variation in birth and death rates. Consequently characterizing birth and death rates, and identifying factors that explain variation in these rates, should be the foundation of population and evolutionary ecology. Given the central role of birth and death, it is perhaps surprising that relatively few population biologists apply the most recent demographic approaches to their research. This may be because demography is seen as little more than accounting, and therefore dull, or because stochastic demography is seen as mathematically challenging. It is our belief that ecologists and evolutionary biologists have much to gain through increased mastery of stochastic demography. Its applications could push forward our understanding of eco-evolutionary dynamics in stochastic environments, and the outcome could further the unification of ecology and evolution. In this essay we briefly explain why mastering demographic approaches should be a desirable objective for any evolutionary ecologist. We start by describing some aspects and insights gained through application of demographic methods, before suggesting an area where we believe application could prove insightful.

scholarly journals Landscape resistance constrains hybridization across contact zones in a reproductively and morphologically polymorphic salamander

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Guillermo Velo-Antón ◽  
André Lourenço ◽  
Pedro Galán ◽  
Alfredo Nicieza ◽  
Pedro Tarroso
Keyword(s):  
Contact Zone ◽  
Environmental Heterogeneity ◽  
Evolutionary Dynamics ◽  
Morphological Differentiation ◽  
Phenotypic Traits ◽  
Hybrid Zones ◽  
Landscape Resistance ◽  
Phenotypic Differentiation ◽  
Contact Zones

AbstractExplicitly accounting for phenotypic differentiation together with environmental heterogeneity is crucial to understand the evolutionary dynamics in hybrid zones. Species showing intra-specific variation in phenotypic traits that meet across environmentally heterogeneous regions constitute excellent natural settings to study the role of phenotypic differentiation and environmental factors in shaping the spatial extent and patterns of admixture in hybrid zones. We studied three environmentally distinct contact zones where morphologically and reproductively divergent subspecies of Salamandra salamandra co-occur: the pueriparous S. s. bernardezi that is mostly parapatric to its three larviparous subspecies neighbours. We used a landscape genetics framework to: (i) characterise the spatial location and extent of each contact zone; (ii) assess patterns of introgression and hybridization between subspecies pairs; and (iii) examine the role of environmental heterogeneity in the evolutionary dynamics of hybrid zones. We found high levels of introgression between parity modes, and between distinct phenotypes, thus demonstrating the evolution to pueriparity alone or morphological differentiation do not lead to reproductive isolation between these highly divergent S. salamandra morphotypes. However, we detected substantial variation in patterns of hybridization across contact zones, being lower in the contact zone located on a topographically complex area. We highlight the importance of accounting for spatial environmental heterogeneity when studying evolutionary dynamics of hybrid zones.

scholarly journals The Genomic Ecosystem of Transposable Elements in Maize

2019 ◽  
Author(s):  
Michelle C. Stitzer ◽  
Sarah N. Anderson ◽  
Nathan M. Springer ◽  
Jeffrey Ross-Ibarra
Keyword(s):  
Transposable Elements ◽  
Evolutionary Dynamics ◽  
Phenotypic Diversity ◽  
Flowering Plant ◽  
Genome Wide ◽  
Family Level ◽  
Genomic Environment ◽  
Single Category ◽  
The Impact

Transposable elements (TEs) constitute the majority of flowering plant DNA, reflecting their tremendous success in subverting, avoiding, and surviving the defenses of their host genomes to ensure their selfish replication. More than 85% of the sequence of the maize genome can be ascribed to past transposition, providing a major contribution to the structure of the genome. Evidence from individual loci has informed our understanding of how transposition has shaped the genome, and a number of individual TE insertions have been causally linked to dramatic phenotypic changes. But genome-wide analyses in maize and other taxa have frequently represented TEs as a relatively homogeneous class of fragmentary relics of past transposition, obscuring their evolutionary history and interaction with their host genome. Using an updated annotation of structurally intact TEs in the maize reference genome, we investigate the family-level ecological and evolutionary dynamics of TEs in maize. Integrating a variety of data, from descriptors of individual TEs like coding capacity, expression, and methylation, as well as similar features of the sequence they inserted into, we model the relationship between these attributes of the genomic environment and the survival of TE copies and families. Our analyses reveal a diversity of ecological strategies of TE families, each representing the evolution of a distinct ecological niche allowing survival of the TE family. In contrast to the wholesale relegation of all TEs to a single category of junk DNA, these differences generate a rich ecology of the genome, suggesting families of TEs that coexist in time and space compete and cooperate with each other. We conclude that while the impact of transposition is highly family- and context-dependent, a family-level understanding of the ecology of TEs in the genome can refine our ability to predict the role of TEs in generating genetic and phenotypic diversity.‘Lumping our beautiful collection of transposons into a single category is a crime’-Michael R. Freeling, Mar. 10, 2017

Friends or Foe?

2022 ◽  
pp. 1412-1435
Author(s):  
Rosalba Manna ◽  
Rocco Palumbo ◽  
Massimiliano Pellegrini
Keyword(s):  
Resource Management ◽  
Business Ethics ◽  
Human Resource Management ◽  
Human Resource ◽  
Family Firms ◽  
Management Practices ◽  
Ethical Challenges ◽  
Human Resource Management Practices ◽  
Push Forward

Scholars have argued that business ethics is a crucial ingredient for the successful recipe of human resource management. However, little is known about the factors that trigger an organizational commitment towards the promotion of an ethical approach in crafting human resource management practices. This is especially true for family firms, whose ethical slant in devising human resource management practices has been under-researched. This chapter intends to push forward our knowledge in the field of business ethics investigating the role of familiness in determining ethically-rooted human resource management practices among small and medium-sized enterprises. More specifically, the authors investigated how awareness of business ethics issues and formalization of human resource management policies and practices affect the SMEs commitment to ethics. Family firms were found to be aware of the ethical challenges that characterize human resource management; however, no evidence was retrieved about the role of familiness in triggering an ethical commitment in managing human resources.

The role of biotic interactions in invasion ecology: theories and hypotheses.

2020 ◽  
pp. 26-44
Author(s):  
Cang Hui ◽  
◽  
Pietro Landi ◽  
Guillaume Latombe ◽  
◽  
...  
Keyword(s):  
Native Species ◽  
Evolutionary Dynamics ◽  
Biotic Interactions ◽  
Evolutionary Games ◽  
Invasion Ecology ◽  
Ecological Communities ◽  
Dynamic Interactions ◽  
Ecological Fitting ◽  
And Function

Changes in biotic interactions in the native and invaded range can enable a non-native species to establish and spread in novel environments. Invasive non-native species can in turn generate impacts in recipient systems partly through the changes they impose on biotic interactions; these interactions can lead to altered ecosystem processes in the recipient systems. This chapter reviews models, theories and hypotheses on how invasion performance and impact of introduced species in recipient ecosystems can be conjectured according to biotic interactions between native and non-native species. It starts by exploring the nature of biotic interactions as ensembles of ecological and evolutionary games between individuals of both the same and different groups. This allows us to categorize biotic interactions as direct and indirect (i.e. those involving more than two species) that emerge from both coevolution and ecological fitting during community assembly and invasion. We then introduce conceptual models that can reveal the ecological and evolutionary dynamics between interacting non-native and resident species in ecological networks and communities. Moving from such theoretical grounding, we review 20 hypotheses that have been proposed in invasion ecology to explain the invasion performance of a single non-native species, and seven hypotheses relating to the creation and function of assemblages of non-native species within recipient ecosystems. We argue that, although biotic interactions are ubiquitous and quintessential to the assessment of invasion performance, they are nonetheless difficult to detect and measure due to strength dependency on sampling scales and population densities, as well as the non-equilibrium transient dynamics of ecological communities and networks. We therefore call for coordinated efforts in invasion science and beyond, to devise and review approaches that can rapidly map out the entire web of dynamic interactions in a recipient ecosystem.

scholarly journals The role of multilevel selection in host microbiome evolution

2019 ◽  
Vol 116 (41) ◽  
pp. 20591-20597 ◽  
Author(s):  
Simon van Vliet ◽  
Michael Doebeli
Keyword(s):  
Generation Time ◽  
Evolutionary Dynamics ◽  
Horizontal Transmission ◽  
Multilevel Selection ◽  
Microbiome Composition ◽  
Active Debate ◽  
Multilevel Selection Theory ◽  
Verbal Arguments ◽  
Host Generation

Animals are associated with a microbiome that can affect their reproductive success. It is, therefore, important to understand how a host and its microbiome coevolve. According to the hologenome concept, hosts and their microbiome form an integrated evolutionary entity, a holobiont, on which selection can potentially act directly. However, this view is controversial, and there is an active debate on whether the association between hosts and their microbiomes is strong enough to allow for selection at the holobiont level. Much of this debate is based on verbal arguments, but a quantitative framework is needed to investigate the conditions under which selection can act at the holobiont level. Here, we use multilevel selection theory to develop such a framework. We found that selection at the holobiont level can in principle favor a trait that is costly to the microbes but that provides a benefit to the host. However, such scenarios require rather stringent conditions. The degree to which microbiome composition is heritable decays with time, and selection can only act at the holobiont level when this decay is slow enough, which occurs when vertical transmission is stronger than horizontal transmission. Moreover, the host generation time has to be short enough compared with the timescale of the evolutionary dynamics at the microbe level. Our framework thus allows us to quantitatively predict for what kind of systems selection could act at the holobiont level.

scholarly journals Transcriptional Mutagenesis Prevents Ribosomal DNA Deterioration: The Role of Duplications and Deletions

2019 ◽  
Vol 11 (11) ◽  
pp. 3207-3217
Author(s):  
Enrico Sandro Colizzi ◽  
Paulien Hogeweg
Keyword(s):  
Genome Stability ◽  
Evolutionary Dynamics ◽  
Point Mutations ◽  
Gene Duplications ◽  
Genetic Operators ◽  
Theory Of Evolution ◽  
Long Term Stability ◽  
Number Variation

Abstract Clashes between transcription and replication complexes can cause point mutations and chromosome rearrangements on heavily transcribed genes. In eukaryotic ribosomal RNA genes, the system that prevents transcription–replication conflicts also causes frequent copy number variation. Such fast mutational dynamics do not alter growth rates in yeast and are thus selectively near neutral. It was recently found that yeast regulates these mutations by means of a signaling cascade that depends on the availability of nutrients. Here, we investigate the long-term evolutionary effect of the mutational dynamics observed in yeast. We developed an in silico model of single-cell organisms whose genomes mutate more frequently when transcriptional load is larger. We show that mutations induced by high transcriptional load are beneficial when biased toward gene duplications and deletions: they decrease mutational load even though they increase the overall mutation rates. In contrast, genome stability is compromised when mutations are not biased toward gene duplications and deletions, even when mutations occur much less frequently. Taken together, our results show that the mutational dynamics observed in yeast are beneficial for the long-term stability of the genome and pave the way for a theory of evolution where genetic operators are themselves cause and outcome of the evolutionary dynamics.

On tropical mistletoes: tractable models for evolutionary ecology, ecosystem function, and phytochemistry

Botany ◽  
2017 ◽  
Vol 95 (3) ◽  
pp. 211-217 ◽  
Author(s):  
David M. Watson
Keyword(s):  
Seed Dispersal ◽  
Host Range ◽  
Plant Communities ◽  
Ecosystem Function ◽  
Evolutionary Ecology ◽  
Life Sciences ◽  
Evolutionary Trajectory ◽  
Tropical Regions ◽  
Wide Range

In 2001, I synthesised published information on mistletoe–animal interactions, demonstrating the pervasive influence these hemiparasites have on community composition and proposing that mistletoes represent keystone resources. Although the review was global in scope, I noted “Tropical regions, in particular, are underrepresented in the mistletoe literature, and it is unclear if mistletoe is as important in structuring these highly diverse ecosystems as in less diverse temperate areas”. Since then, research on tropical mistletoes has burgeoned, as a growing number of researchers use these forest and woodland hemiparasites to address a wide range of ecological and evolutionary questions. In this commentary, I highlight some recent findings, revisit and refine some emergent inferences, and suggest that tropical mistletoes offer many opportunities for further research, representing tractable models to address many unanswered questions in the life sciences. As well as reinforcing the role of mistletoes as facilitators for plant communities and keystone resources for animal assemblages, research on mistletoe pollination, seed dispersal, and host-range, challenge the established views about the ecological maintenance and evolutionary trajectory of specialization.

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