Which parental gene gets the upper hand

Hand-clasping is sometimes used to illustrate basic genetics; the myth is that hand-clasping is controlled by one gene with two alleles, and the allele for L is dominant. I do not know how this myth started, as from the first study Lutz onwards, it has been clear that hand-clasping preference does not fit this simple myth. Most people have a strong preference for clasping their hands in one way, either with the left thumb on top L or the right thumb on top R. To most people, it feels unnatural to clasp the hands in the opposite way, making it a very easy trait to observe.

Surveys indicate that roughly half of the people studied are R and half are L Wiener , Freire-Maia et al. Reiss , reviewed nearly publications that have surveyed hand-clasping frequencies in populations around the world. There were a few populations with particularly high or low frequencies of left-over-right claspers, but most populations had between 40 and 75 percent L.

The proportion of people with no preference for L or R was about 1 percent. Reiss summarized data from 18 studies of parents and offspring, with the following totals across all studies:. Reiss concluded that there may be some genetic basis for this character because LxL matings produce more L offspring than do RxR matings , but it is not a simple one-gene, two-allele genetic character.

If the myth were true, two R parents could not have an L child, but almost a third of the children of RxR matings are L. Do plant secondary compounds induce epigenetic changes that confer resistance or susceptibility to toxicosis in animals. The complex dance between parents and child: the sex of all 3 modifies phenotype. Genomic imprinting: parental influence on the genome. Genomic imprinting effects on brain development and function. The … Expand. What good is genomic imprinting: the function of parent-specific gene expression.

Epigenetics, brain evolution and behaviour. Ultimately, the slower reproducing organelle lineage will be eliminated from the cell lineage. Thus, competition among organelles within cells selects for smaller genomes.

At some stage genomes will be so small that the function of the organelle is affected. Remember that the mitochondria produce the energy the cell needs, so when their genome size becomes very small, the organelles cease to function properly and the host cell suffers.

Recently a much simpler explanation was proposed: what if the simple mixing of mitochondrial lineages within the same cell is for some reason costly in itself? This very simple assumption actually nicely explains the peculiar inheritance of mitochondria in theoretical models. But there is more. Mice that were experimentally constructed so that individuals carried two mitochondrial lineages were less active, ate less, were more stressed and were cognitively impaired.

It seems carrying mitochondria from both your parents is bad for you. So why is the question of whether you are more like your mum or dad so hard to answer?

Because your genetic make-up is only part of the equation. Science , pp. Things used to be relatively straightforward when it came to parental influences on gene action. Mom and Dad passed on one copy or allele of each autosomal gene to their progeny and overall, the expression and function of genes inherited by the offspring were indifferent to which parent they came from.