Developmental Instability and Individual Variation in Brain Development

2007 ◽  
Vol 16 (5) ◽  
pp. 245-249 ◽  
Author(s):  
Ronald A. Yeo ◽  
Steven W. Gangestad ◽  
Robert J. Thoma
Keyword(s):  
Genetic Diversity ◽  
Brain Development ◽  
Individual Variation ◽  
Neurodevelopmental Disorders ◽  
Evolutionary Genetics ◽  
Developmental Instability ◽  
Normal Variation ◽  
Research Strategies ◽  
Causal Factors ◽  
Different Types

Research on the origin of neurodevelopmental disorders has traditionally been pursued within a constrained, disorder-specific perspective. The developmental instability (DI) model described here offers a broader approach based on the evolutionary genetics of normal variation, reflecting our understanding that the processes generating genetic diversity are not unique to any specific disorder. The DI model helps account for shared features, including atypical functional and anatomic asymmetries, reduced general intellectual functioning, and complex patterns of heritability, across different types of neural variation. The model suggests research strategies that may help illuminate the specific and unique causal factors characterizing different types of neural variation.

Evolutionary genetics of small populations

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Evolutionary Genetics ◽  
Small Population ◽  
Small Populations ◽  
Effective Population ◽  
Genetic Management ◽  
Evolutionary Genetic ◽  
Loss Of Genetic Diversity ◽  
Number Of Individuals

Genetic management of fragmented populations involves the application of evolutionary genetic theory and knowledge to alleviate problems due to inbreeding and loss of genetic diversity in small population fragments. Populations evolve through the effects of mutation, natural selection, chance (genetic drift) and gene flow (migration). Large outbreeding, sexually reproducing populations typically contain substantial genetic diversity, while small populations typically contain reduced levels. Genetic impacts of small population size on inbreeding, loss of genetic diversity and population differentiation are determined by the genetically effective population size, which is usually much smaller than the number of individuals.

scholarly journals Evolutionary Genetics of Mycobacterium tuberculosis and HIV-1: “The Tortoise and the Hare”

2021 ◽  
Vol 9 (1) ◽  
pp. 147
Author(s):  
Ana Santos-Pereira ◽  
Carlos Magalhães ◽  
Pedro M. M. Araújo ◽  
Nuno S. Osório
Keyword(s):  
Genetic Diversity ◽  
Drug Resistance ◽  
Mycobacterium Tuberculosis ◽  
Evolutionary Dynamics ◽  
Evolutionary Genetics ◽  
Host Cells ◽  
Whole Genome Sequencing Data ◽  
Host Immune System ◽  
Viral Mutant ◽  
Hiv 1

The already enormous burden caused by Mycobacterium tuberculosis and Human Immunodeficiency Virus type 1 (HIV-1) alone is aggravated by co-infection. Despite obvious differences in the rate of evolution comparing these two human pathogens, genetic diversity plays an important role in the success of both. The extreme evolutionary dynamics of HIV-1 is in the basis of a robust capacity to evade immune responses, to generate drug-resistance and to diversify the population-level reservoir of M group viral subtypes. Compared to HIV-1 and other retroviruses, M. tuberculosis generates minute levels of genetic diversity within the host. However, emerging whole-genome sequencing data show that the M. tuberculosis complex contains at least nine human-adapted phylogenetic lineages. This level of genetic diversity results in differences in M. tuberculosis interactions with the host immune system, virulence and drug resistance propensity. In co-infected individuals, HIV-1 and M. tuberculosis are likely to co-colonize host cells. However, the evolutionary impact of the interaction between the host, the slowly evolving M. tuberculosis bacteria and the HIV-1 viral “mutant cloud” is poorly understood. These evolutionary dynamics, at the cellular niche of monocytes/macrophages, are also discussed and proposed as a relevant future research topic in the context of single-cell sequencing.

scholarly journals Distinct selective forces and Neanderthal introgression shaped genetic diversity at genes involved in neurodevelopmental disorders

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Alessandra Mozzi ◽  
Diego Forni ◽  
Rachele Cagliani ◽  
Uberto Pozzoli ◽  
Mario Clerici ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Neurodevelopmental Disorders ◽  
Selective Forces

scholarly journals Autism as a disorder of neural information processing: Directions for research and targets for therapy

2019 ◽  
Author(s):  
Matthew Belmonte ◽  
John Rubenstein
Keyword(s):  
Brain Development ◽  
Autism Spectrum ◽  
Behavioural Syndrome ◽  
Neural Systems ◽  
Developmental Courses ◽  
Genetic Syndromes ◽  
Causal Factors ◽  
Neural Information ◽  
Neural Information Processing ◽  
Broad Variation

The broad variation in phenotypes and severities within autism spectrum disorders suggests the involvement of multiple predisposing factors, interacting in complex ways with normal developmental courses and gradients. Identification of these factors, and the common developmental path into which they feed, is hampered by the large degrees of convergence from causal factors to altered brain development, and divergence from abnormal brain development into altered cognition and behaviour. Genetic, neurochemical, neuroimaging and behavioural findings on autism, as well as studies of normal development and of genetic syndromes that share symptoms with autism, offer hypotheses as to the nature of causal factors and their possible effects on the structure and dynamics of neural systems. Such alterations in neural properties may in turn perturb activity-dependent development, giving rise to a complex behavioural syndrome many steps removed from the root causes. Animal models based on genetic, neurochemical, neurophysiological, and behavioural manipulations offer the possibility of exploring these developmental processes in detail, as do human studies addressing endophenotypes beyond the diagnosis itself.

scholarly journals Genetic Diversity of Soil Bacteria

Diversity ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 414
Author(s):  
Carmine Crecchio
Keyword(s):  
Genetic Diversity ◽  
Bacterial Communities ◽  
Soil Bacteria ◽  
Agricultural Soils ◽  
Field Trials ◽  
Laboratory Scale ◽  
Special Issue ◽  
Soil Bacterial Communities ◽  
Review Articles ◽  
Different Types

The Special Issue “Genetic Diversity of Soil Bacterial Communities” collected research and review articles addressing some relevant and unclear aspects of the composition and functioning of bacterial communities in rich or marginal agricultural soils, in field trials as well as in laboratory-scale experiments, at different latitudes and under different types of management.

Individual differences: Variation by design

2000 ◽  
Vol 23 (5) ◽  
pp. 676-677 ◽  
Author(s):  
Anthony J. Greene ◽  
William B. Levy
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Individual Differences ◽  
Natural Selection ◽  
Individual Variation ◽  
Mate Selection ◽  
Behavioral Variability ◽  
Behavioral Variation ◽  
Absolute Necessity

Stanovich & West (S&W) appear to overlook the adaptivity of variation. Behavioral variability, both between and within individuals, is an absolute necessity for phylogenetic and ontological adaptation. As with all heritable characteristics, inter-individual behavioral variation is the foundation for natural selection. Similarly, intra-individual variation allows a broad exploration of potential solutions. Variation increases the likelihood that more optimal behaviors are available for selection. Four examples of the adaptivity of variation are discussed: (a) Genetic variation as it pertains to behavior and natural selection; (b) behavioral and cognitive aspects of mate selection which may facilitate genetic diversity; (c) variation as a strategy for optimizing learning through greater exploration; and (d) behavioral variation coupled with communication as a means to propagate individually discovered behavioral success.

scholarly journals Controlled fire use in early humans might have triggered the evolutionary emergence of tuberculosis

2016 ◽  
Vol 113 (32) ◽  
pp. 9051-9056 ◽  
Author(s):  
Rebecca H. Chisholm ◽  
James M. Trauer ◽  
Darren Curnoe ◽  
Mark M. Tanaka
Keyword(s):  
Bacterial Pathogen ◽  
Evolutionary Genetics ◽  
Human Populations ◽  
Causal Factors ◽  
Fire Use ◽  
Early Humans ◽  
Successful Group ◽  
Evolutionary Emergence ◽  
Transmissible Disease ◽  
The Ideal

Tuberculosis (TB) is caused by the Mycobacterium tuberculosis complex (MTBC), a wildly successful group of organisms and the leading cause of death resulting from a single bacterial pathogen worldwide. It is generally accepted that MTBC established itself in human populations in Africa and that animal-infecting strains diverged from human strains. However, the precise causal factors of TB emergence remain unknown. Here, we propose that the advent of controlled fire use in early humans created the ideal conditions for the emergence of TB as a transmissible disease. This hypothesis is supported by mathematical modeling together with a synthesis of evidence from epidemiology, evolutionary genetics, and paleoanthropology.

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