"Intragenomic conflicts (such as those between maternally and paternally expressed genes) also tend to produce maladaptive outcomes for the person as a whole. In the presence of intragenomic conflict, the developing phenotype is subject to opposing forces, much like in a game of tug-of-war. The tension between different sets of genes with opposite effects increases phenotypic variability and, consequently, the likelihood of reaching maladaptive levels of trait expression. If for any reason the dynamic equilibrium is broken - for example because of disruptive mutations on one side of the conflict - the resulting unbalance may easily determine dysregulated or frankly pathological outcomes. Conflicts between brain-expressed imprinted genes seem to play a role in the development of some mental disorders, most notably autism, schizophrenia, and other psychotic conditions ( Byars et al., 2014; Crespi & Badcock, 2008; Crespi et al., 2010; Wilkins, 2011)."
Marco Del Giudice; Evolutionary Psychiatry
One interesting way to understand this is observing couples which one or majority of their children born looking fundamentally one of them, as if just one of the parents genes were expressed. I have a adopted cousin who are mulato and she had a daughter with a white man. Her daughter is basically a perfect copy of father. The idea that genetics is always a combination of parents seems possibly wrong because sometimes the genes of one of them will be totally expressed and the other totally supressed. Even in psychological aspects this girl appear to look like her father than my cousin.
AntwortenLöschenIndeed it's an interesting observation that some children are much more similar to one parent than to the other.
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