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Common Misconceptions in Genetics

Shashank Nakate Oct 21, 2020
In the mid-19th century, Gregor Mendel propagated his theories related to heredity. A lot of progress has been made in the field of genetics since then. However, even today, there exist a lot of misconceptions owing to incorrect understanding of its concepts. Here is an account of the common misconceptions in genetics.

Low Culture Sources

Research points out that the idea of associating heredity only with DNA or genes is derived from low culture sources, such as movies, comic books, sitcoms, etc. Most of the misconceptions in genetics originate from information presented through such sources.
Genetics, in simple words, can be described as the science of genes. The concepts of inheritance and variations in living beings are covered under the study of genetics. It is a bit complex and difficult to understand, and the complexity gives rise to a number of misconceptions.
Scientific concepts can be understood correctly only if they are explained to students in an easy-to-understand manner. In case of a complex subject like genetics, this becomes even more important. Explaining the concepts, taking into account the minutest details becomes necessary. They can be understood on a macro, micro, and symbolic level.
A correct or rather complete understanding cannot be obtained only from either of these levels.
Misconceptions arise from an incorrect understanding of a concept or phenomenon. Many a time, an ill-informed understanding of a concept is propagated through media or through hearsay.
Therefore, it becomes necessary to verify the information before you accept it as a fact. It is difficult to unlearn a particular concept, once you believe it as true.

Myths and Misconceptions in Genetics

Genes, DNA testing, chromosomes, and related terms and concepts, have become familiar due to their occurrence in popular media. Some of the common misconceptions in genetics and their correct explanations are discussed ahead.

Genes Determine All Traits

It is necessary to understand that not all behavioral patterns of an organism are controlled by genes. Learning from experience and epigenetic inheritance are among the other factors responsible for controlling a person's behavior.
Epigenetic Inheritance: The form of inheritance in which traits inherited by an organism don't get encoded by genes is known as epigenetic inheritance. It means the phenomenon of inheritance is not entirely governed by DNA sequences.
All Mutations are Harmful
A permanent change caused to a DNA sequence is known as mutation. There is general perception among people that all mutations are harmful for the body. This misconception about mutants and the process of mutation generally originates in science-fiction, comics, movies, etc. Mutations are part of the process of evolution, and evolution is an ongoing process.
Many of us are not aware of the fact that, along with harmful mutations, beneficial mutations also take place in the body. The following example presents information of a beneficial gene.
There is a gene present in humans which codes for the Apolipoprotein AI. This protein helps in removing cholesterol from the walls of the arteries. The mutant of this gene which codes for Apolipoprotein AI-Milano is more effective than the Apolipoprotein AI. In addition to removing cholesterol from artery walls, the protein also functions as an antioxidant.

Dominant Alleles are Found in Abundance

A gene is formed of alleles. The term dominant allele is mistaken for the allele found in great number in nature.
Those who don't have a correct understanding of the concept of dominant allele jump to the conclusion that dominant alleles are of common occurrence in nature. For a gene to be found in greater proportion in nature, there needs to be more copies of it. The concept of dominant allele has nothing to do with the number of genes or their alleles.
A dominant allele is one which gets expressed phenotypically; when a dominant allele is phenotypically expressed, the recessive allele gets suppressed. If a gene contains a dominant allele 'X' and recessive allele, 'x', the dominant one suppresses the recessive one, and the gene is phenotypically expressed as 'X'.

Clones are Carbon Copies of the Original

A clone is perceived as the replica of its original organism. A clone is not exactly the same as its original.
Clones are very much like identical twins. Their genetic makeup is almost the same. However, even if clones are genetically identical, their behavioral pattern can be different from each other. In fact, even the genetic traits may not appear in clones exactly as they are found in the original.
For example, the clone may have a skin coat which is different from that of the original.
The behavioral patterns and other phenotypically-expressed traits are shaped, not just by genes, but also by environmental factors. Experiences also determine the traits of a clone. Thus, clones are not the carbon copies of their originals. Understanding the animal cloning process should present some useful insights on the topic of cloning.

A Gene for Every Trait

One of the misconceptions about genetics is that a single gene (set of alleles) determines a single trait/attribute.
A deeper understanding would reveal that this assumption does not hold true for all genes or traits. For example, eye color is determined by at least 3 genes. As per recent research (Barsh, 2003), the color of the skin is determined by about 100 genes.
A phenotypic expression cannot always be attributed to only a single gene. Therefore, a particular trait or attribute can be determined by more than one gene. Also, many other factors, including environmental, are responsible for the phenotypic expression of a trait.

Genes as Blueprint of the Body

It is often said, out of ignorance, that genes provide a blueprint of the functioning of the body.
Analogy between genes and architectural blueprints is drawn, taking into account the properties shared by them on a superficial level. However, in reality, the one-dimensional model of genes (organized into a string of nucleotides) doesn't hold true.
The flow of information originating from genes is not always a one-way flow. The chain of causality doesn't operate in isolation. In a biochemical system, different elements are entangled with each other. Therefore, it is difficult to single out a certain gene for a particular functionality.
Finally, one should understand that there are many elements which act together in the smooth functioning of biochemical systems.
Genetics is a complex subject, and it is not surprising to find that there are many misconceptions about the different concepts of genetics.
Although genes determine most of the characteristics in a living being, there are many other factors which come into play in determining its behavioral traits and patterns.