5 Common Myths and Misconceptions about Genetics

Due to the rising popularity of DNA tests, many people are fascinated by the world of DNA and genetics. However, there are many misconceptions and myths about genetics. Below are five of the most common.

1. Only Two Sets of Alleles Are Responsible for a Trait

The truth is, every gene has only two kinds of alleles: dominant and recessive ones. Some people erroneously believe that all traits can be predictably and easily modelled on the shallow understanding of sex-linked traits and Mendelian inheritance. For instance, eye colour is associated with three different genes while not less than six genes influence the colour of a cat’s coat. Furthermore, how some of your characteristics manifest depend on the number of alleles you have inherited.

The alleles you inherit from each of your parents may contain a code that informs the production of melanin, and which determines the colour of your hair. Darker hair could be informed by the inheritance of more alleles while lighter hair may be a result of fewer alleles. Although the assumption that only two alleles are responsible for a trait could be true in some cases, predominantly, a trait has more than two alleles.

2. All Your Characteristics Are Determined by Your Genes, While Cloned Organisms Are Replicas of the Original

Indisputably, genes play a big role in the development of an organism. However, other factors (environmental, for instance) play a role as well. According to epigenetics, an organism can have heritable changes without any change in the genome structure. For instance, a gene expression from identical mice depicts changes wrought by exposure to toxins and diets. Such changes can add up during the life of an organism.

A good illustration is the cloning of a domestic cat called Rainbow whose coat showed calico coloration, while that of Copycat (the clone) was a tabby pattern. Although both Rainbow and Copycat had identical genomes, epigenetic factors must have been responsible for the differences in coat colour.

For more information, you can gain insights by taking a DNA test from CRI Genetics and learn about your genetic characteristics in greater depth.

3. All Mutations Are Harmful

The reality is some mutations are harmful, but not all of them. Mutation refers to a change in an organism’s genetic code. Some mutations interfere with the proper development of an organism. However, there are many silent mutations that are actually beneficial. When mutations are silent, the production of subsequent protein and the amino acid sequence is not affected by genome changes.

An amino acid could be coded by multiple codons, which means a gene product cannot be automatically changed by a change in one nucleotide. The environment in which an organism with a mutation lives determines whether that mutation will be helpful or harmful.

4. The Trait Most Likely to Be Found in a Population Is the Dominant One

The term “dominant allele” is sometimes confused to mean it is the most prevalent in a population. However, the word “dominant” only refers to one allele’s expression over another. Examples abound in human genetics of dominant traits not found among the majority of the population. For instance, this myth is debunked by among other conditions, achondroplasia, a type of dwarfism caused by a dominant allele and yet only 1 in 10,000 live births result in this type of condition.

5. Genetics Terms Are Confusing

Many people struggle with understanding genetic terms such as a gene, an allele, and a chromosome. These terms aren’t so difficult to understand, however.

Chromosomes contain a coiled strand of DNA. They can only be viewed with a microscope during stages of a cell cycle. Genes, on the other hand, are heredity units that create proteins that play specific functions in an organism. Alleles are gene variants.

Dispelling these misconceptions and misunderstandings will demystify the study and practice of genetics. It also helps in understanding how organisms evolve genetically based on their genome structure and other factors such as the environment in which they live.