Most people constantly use one hand to perform tasks Which requires skill and control such as needle writing or threading. We know that heredity plays a big part in what a person chooses in hand, but it has become difficult to identify specific genes responsible.
To find out more, we analyzed the DNA of more than 1.7 million people and associated 41 fields of the genome with left-handed and seven other amphibians.
What makes people left-handed?
About 88% of people prefer to use their right hand for complex tasks, about 10% prefer their left hand, and another 2% report that they do not like it and can use both hands. The choice of hand develops so early that it can be seen in the uterus.
Handness stabilizes around the time children are learning to draw. In the absence of injury or training, it remains stable throughout life. Historic evidence of the human population suggests that it has been this way for thousands of years.
Research examining patterns of handness in twins and families shows that much of the diversity comes down to non-genetic factors such as training and the environment in which we acquire early motor skills. However, heredity plays a significant role.
There is no gene for handness
The idea that a single gene can affect handness has been explored in more than 100 journal articles since the mid-1980s. These theories suggest that one type of gene would favor anyone on the right, while in the alternative type handwriting was randomly determined.
While single genes have provided many theories for explaining different human characteristics, in recent years we have discovered that reality is often more complex. More recent research uses Genome-Wide Association Studies (GWAS) to look at the relationship between curiosity and the number of genetic type copies one has. This analysis is run for millions of variants surrounding the genome.
This genome-wide study shows that almost all human traits are affected by many hundreds or thousands of genetic variants. Often these types are located between genes whose purpose is not clearly identified, which was called “junk DNA”.
GWASA has also shown that most traits are influenced by a large number of genes, with each gene having a rather large effect, with very small effects. Large collaborative studies with multiple participants are needed to track these small influences, to identify the individual genetic types involved.
What GWAS Reveals About Handness
In 2009 we launched a project involving researchers from around the world to hunt genetics that affect handness using genetic (GWAS). We did not recruit participants based on their handness, so the number of people on the left was relatively small. As a result, we have recently gathered enough to do a strong analysis.
Our study brought together data analysis of 1,766,671 people. Of these, 194,198 were leftists and 37,637 were aspirants. We found 41 regions of the genome associated with the left hand and seven regions associated with embeddedity.
Many regions of the genome associated with the left hand include genes that are codes of microtubule proteins. These proteins play an important role in the transfer of neurons and in the development of the brain’s ability to adapt to changes in the environment.
Interestingly, genes affecting other asymmetries in the body, such as which side of the body the heart is located on, are not associated with handness in our study.
Another important finding was that there was little overlap between the regions of the genome associated with the left hand and those associated with ambiguity. This suggests that ambidexia is more complex than we previously thought. Influenced methods Direction Hand choices can vary from influencers Degree Hand selection.
These findings give us promising new leads but more work is needed to identify the genetic types that affect handness. There is still a long way to go before we understand how these variables play a role in someone’s right hand, left hand or being ambitious.
This article was originally published on a conversation by David Evans of the University of Queensland and Sarah Madland at the QIMR Berghofer Medical Research Institute. Read the original article here.
