Browsing by Author "Charney, E"

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    Behavior Genetics and Post Genomics
    (Behavioral and Brain Sciences, 2012-12) Charney, E
    The science of genetics is undergoing a paradigm shift. Recent discoveries, including the activity of retrotransposons, the extent of copy number variations, somatic and chromosomal mosaicism, and the nature of the epigenome as a regulator of DNA expressivity, are challenging a series of dogmas concerning the nature of the genome and the relationship between genotype and phenotype. DNA, once held to be the unchanging template of heredity, now appears subject to a good deal of environmental change; considered to be identical in all cells and tissues of the body, there is growing evidence that somatic mosaicism is the normal human condition; and treated as the sole biological agent of heritability, we now know that the epigenome, which regulates gene expressivity, can be inherited via the germline. These developments are particularly significant for behavior genetics for at least three reasons: First, these phenomena appear to be particularly prevalent in the human brain, and likely are involved in much of human behavior; second, they have important implications for the validity of heritability and gene association studies, the methodologies that largely define the discipline of behavior genetics; and third, they appear to play a critical role in development during the perinatal period, and in enabling phenotypic plasticity in offspring in particular. I examine one of the central claims to emerge from the use of heritability studies in the behavioral sciences, the principle of “minimal shared maternal effects,” in light of the growing awareness that the maternal perinatal environment is a critical venue for the exercise of adaptive phenotypic plasticity. This consideration has important implications for both developmental and evolutionary biology
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    Behavioural Genetics in the Postgenomics Era
    (eLS, 2014-01-01) Charney, E
    There is growing evidence that the complexity of higher organisms does not correlate with the ‘complexity’ of the genome (the human genome contains fewer protein coding genes than corn, and many genes are preserved across species). Rather, complexity is associated with the complexity of the pathways and processes whereby the cell utilises the deoxyribonucleic acid molecule, and much else, in the process of phenotype formation. These pro- cesses include the activity of the epigenome, noncoding ribonucleic acids, alternative splicing and post-transla- tional modifications. Not accidentally, all of these pro- cesses appear to be of particular importance for the human brain, the most complex organ in nature. Because these processes can be highly environmentally reactive, they are a key to understanding behavioural plasticity and highlight the importance of the developmental process in explaining behavioural outcomes.
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    Candidate genes and political behavior
    (American Political Science Review, 2012-02-01) Charney, E; English, W
    Political scientists are making increasing use of the methodologies of behavior genetics in an attempt to uncover whether or not political behavior is heritable, as well as the specific genotypes that might act as predisposing factors for-or predictors of-political henotypes. Noteworthy among the latter are a series of candidate gene association studies in which researchers claim to have discovered one or two common genetic variants that predict such behaviors as voting and political orientation. We critically examine the candidate gene association study methodology by considering, as a representative example, the recent study by Fowler and Dawes according to which two genes predict voter turnout. In addition to demonstrating, on the basis of the data set employed by Fowler and Dawes, that two genes do not predict voter turnout, we consider a number of difficulties, both methodological and genetic, that beset the use of gene association studies, both candidate and genome-wide, in the social and behavioral sciences. © 2012 American Political Science Association.
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    Genetic Diversity, Population Density, and Per Capita Income
    Charney, E; Rausher, Mark
    In an article published in 2013, Ashrof and Gaylor claim to have empirically established the hypothesis that degree of genetic heterozygosity within a population, as a function of migratory distance from East Africa, has a significant effect upon comparative economic development and that there is an optimal level of heterozygosity. Key to their analysis are two assumptions: First, that heterozygosity of neutral microsatellite markers is a valid proxy for functional genetic heterozygosity; and second, that there exist relatively accurate estimates of global population densities circa 1500 CE, and in particular for Africa, the Americas, and Oceana. We demonstrate that both of these assumptions are false and that consequently, Ashraf and Gaylor have not established their hypothesis.
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    Genetics and the Life Course
    (Emerging Trends in the Social and Behavioral Sciences, 2015-01-01) Charney, E
    A life-course perspective is committed to the proposition that from conception to death, all human outcomes are the result of a continual interaction between the indi- vidual and all of the environments that he or she inhabits at any given point in time. Early development is a critical period, a window of time during the life course when a given exposure can have a critical or permanent in uence on later outcomes. But the impact of exposures upon outcomes does not end at any speci c point in time, inasmuch as life is a continuing interactive and adaptive process. We now know that what applies to human beings also applies to their genomes. The “outcome” of any gene at any given point in time (whether or not it is used to transcribe a particular protein, what form of that protein, and how much) is a product of the interaction between the gene and the multiple environments of which it is a part, which include the epigenome, the cell, the biological human, and the assorted environments he or she occupies (e.g., geographical, socioeconomic, ethnic, etc.). Early life experiences can permanently “reprogram” the epigenome and gene transcription with life-long behavioral consequences. At the same time, the epigenome as well as the genome continue to be environmentally responsive throughout the life course.
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    Genopolitics and the science of genetics
    (American Political Science Review, 2013-04-01) Charney, E; English, W
    In an earlier article we challenged the findings of Fowler and Dawes (FD) that two genes predict voter turnout as part of a more general critique of genopolitics. FD now acknowledge that their finding of a significant direct association between MAOA and voting was incorrect, but claim to have replicated their finding of an indirect association between 5HTT, self-reported church attendance, and self-reported voting. We show that this finding is likely driven by population stratification and omitted variable bias. We then explain why, from the standpoints of genetics, neuroscience, and evolutionary biology, genopolitics is a fundamentally misguided undertaking; we also respond to FD's charge that some of our previous statements concerning genetics are highly misleading, extremely disingenuous, and even incorrect. We show that their criticisms demonstrate a lack of awareness of some basic principles in genetics and of discoveries in molecular genetics over the past 50 years. Copyright © 2013 American Political Science Association.