The Role of Constructive Neutral Evolution in the Development of Complexity from Symbioses: A Microbe-Centric View

2020 ◽  
pp. 225-235
Author(s):  
Ramakrishnan Sitaraman
Keyword(s):  
Neutral Evolution ◽  
Constructive Neutral Evolution

scholarly journals The generality of Constructive Neutral Evolution

2018 ◽  
Vol 33 (1-2) ◽  
Author(s):  
T. D. P. Brunet ◽  
W. Ford Doolittle
Keyword(s):  
Neutral Evolution ◽  
Constructive Neutral Evolution

scholarly journals The Role of Reticulate Evolution in Creating Innovation and Complexity

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Kristen S. Swithers ◽  
Shannon M. Soucy ◽  
J. Peter Gogarten
Keyword(s):  
Metabolic Pathways ◽  
Driving Forces ◽  
Reticulate Evolution ◽  
Neutral Evolution ◽  
Ecological Niches ◽  
Eukaryotic Evolution ◽  
New Host ◽  
Whole Genome Duplications ◽  
Genome Duplications

Reticulate evolution encompasses processes that conflict with traditional Tree of Life efforts. These processes, horizontal gene transfer (HGT), gene and whole-genome duplications through allopolyploidization, are some of the main driving forces for generating innovation and complexity. HGT has a profound impact on prokaryotic and eukaryotic evolution. HGTs can lead to the invention of new metabolic pathways and the expansion and enhancement of previously existing pathways. It allows for organismal adaptation into new ecological niches and new host ranges. Although many HGTs appear to be selected for because they provide some benefit to their recipient lineage, other HGTs may be maintained by chance through random genetic drift. Moreover, some HGTs that may initially seem parasitic in nature can cause complexity to arise through pathways of neutral evolution. Another mechanism for generating innovation and complexity, occurring more frequently in eukaryotes than in prokaryotes, is gene and genome duplications, which often occur through allopolyploidizations. We discuss how these different evolutionary processes contribute to generating innovation and complexity.

Comment on “Does constructive neutral evolution play an important role in the origin of cellular complexity?” DOI 10.1002/bies.201100010

BioEssays ◽  
2011 ◽  
Vol 33 (6) ◽  
pp. 427-429 ◽  
Author(s):  
W. Ford Doolittle ◽  
Julius Lukeš ◽  
John M. Archibald ◽  
Patrick J. Keeling ◽  
Michael W. Gray
Keyword(s):  
Neutral Evolution ◽  
Constructive Neutral Evolution

scholarly journals Specialization of a polyphenism switch gene following serial duplications in Pristionchus nematodes

2016 ◽  
Author(s):  
Erik J. Ragsdale ◽  
Nicholas A. Ivers
Keyword(s):  
Developmental Plasticity ◽  
Genetic Basis ◽  
Reverse Genetics ◽  
Purifying Selection ◽  
Neutral Evolution ◽  
Gene Duplications ◽  
Natural Isolates ◽  
Switch Mechanism ◽  
Population Genetic Analyses

AbstractPolyphenism is an extreme manifestation of developmental plasticity, requiring distinct developmental programs and the addition of a switch mechanism. Because the genetic basis of polyphenism switches has only begun to be understood, how their mechanisms arise is unclear. In the nematode Pristionchus pacificus, which has a mouthpart polyphenism specialized for alternative diets, a gene (eud-1) executing the polyphenism switch was recently identified as the product of lineage-specific duplications. Here we infer the role of gene duplications in producing a switch gene. Using reverse genetics and population genetic analyses, we examine evidence for competing scenarios of degeneration and complementation, neutral evolution, and functional specialization. Of the daughter genes, eud-1 alone has assumed switch-like regulation of the mouth polyphenism. Measurements of life-history traits in single, double, and triple sulfatase mutants did not, given modest sample sizes and a benign environment, identify alternative or complementary roles for eud-1 paralogs. Although possible roles are still unknown, selection analyses of the sister species and 104 natural isolates of P. pacificus detected purifying selection on the genes, suggesting their functionality by their fixation and evolutionary maintenance. Our approach shows the tractability of reverse genetics in a non-traditional model system to study evolution by gene duplication.

scholarly journals No evidence for genetic differentiation in juvenile traits between Belgian and French populations of the invasive tree Robinia pseudoacacia

2018 ◽  
Vol 151 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Xavier P. Bouteiller ◽  
Frédéric Barraquand ◽  
Pauline Garnier-Géré ◽  
Noémie Harmand ◽  
Yec’han Laizet ◽  
...  
Keyword(s):  
Life History ◽  
Genetic Differentiation ◽  
Local Adaptation ◽  
Life History Traits ◽  
Genetic Interaction ◽  
Robinia Pseudoacacia ◽  
Neutral Evolution ◽  
Evolutionary Mechanisms ◽  
Invasive Tree

Background – The role of evolution in biological invasion studies is often overlooked. In order to evaluate the evolutionary mechanisms behind invasiveness, both quantitative and population genetics studies are underway on Robinia pseudoacacia L., one of the worst invasive tree species in Europe.Methods – A controlled experiment was set up using 2000 seeds from ten populations in Southern France and ten populations in Belgium. Seedlings were cultivated in two climatic chambers set at 18°C and 22°C. Early development life history traits (e.g. seedling phenology) and functional traits (e.g. growth rates) were monitored. Genotyping using SNP markers was used to evaluate the genetic differentiation among the populations and a QST – FST comparison was done in order to test for the role of selection.Results – Populations exhibited a strong plasticity to temperature for all measured traits, the warmer environment being generally more suitable, irrespective of their origin. No significant departure from neutral evolution was evidenced by the QST – FST comparisons, although we found a slightly significant differentiation at the molecular level. Conclusion – Plasticity for the functional and life history traits was evidenced but no genetic interaction suggesting no possible evolution of plasticity at those traits. Moreover, no support for genetic differentiation and local adaptation was found among studied populations within invasive range, raising two main questions: first, what is the role of selection on functional and life-history traits; and second, is the elapsed time since first introduction sufficient to allow evolution and local adaptation?

scholarly journals Treatment Strategies Considering Micro-Environment and Clonal Evolution in Multiple Myeloma

Cancers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 215
Author(s):  
Kazuhito Suzuki ◽  
Kaichi Nishiwaki ◽  
Shingo Yano
Keyword(s):  
Multiple Myeloma ◽  
Drug Resistance ◽  
De Novo ◽  
Clonal Evolution ◽  
Proteasome Inhibitors ◽  
Treatment Strategies ◽  
Neutral Evolution ◽  
Acquired Drug Resistance ◽  
Immunological Surveillance

Multiple myeloma is an uncurable hematological malignancy because of obtained drug resistance. Microenvironment and clonal evolution induce myeloma cells to develop de novo and acquired drug resistance, respectively. Cell adhesion-mediated drug resistance, which is induced by the interaction between myeloma and bone marrow stromal cells, and soluble factor-mediated drug resistance, which is induced by cytokines and growth factors, are two types of de novo drug resistance. The microenvironment, including conditions such as hypoxia, vascular and endosteal niches, contributes toward de novo drug resistance. Clonal evolution was associated with acquired drug resistance and classified as branching, linear, and neutral evolutions. The branching evolution is dependent on the microenvironment and escape of immunological surveillance while the linear and neutral evolution is independent of the microenvironment and associated with aggressive recurrence and poor prognosis. Proteasome inhibitors (PIs), immunomodulatory drugs (IMiDs), monoclonal antibody agents (MoAbs), and autologous stem cell transplantation (ASCT) have improved prognosis of myeloma via improvement of the microenvironment. The initial treatment plays the most important role considering de novo and acquired drug resistance and should contain PIs, IMIDs, MoAb and ASCT. This review summarizes the role of anti-myeloma agents for microenvironment and clonal evolution and treatment strategies to overcome drug resistance.

Sign in / Sign up

Export Citation Format

Share Document