What is Crossing Over and Why is it Important in Different Aspects?

Just like the world has progressed in the field of technology, artificial intelligence, and computer sciences, we have also been making progress in biological sciences. The introduction of biotechnology as a field in our lives has revealed many facts about living organisms and their genes. Through biotechnology, concepts like crossing over and genetic mapping were introduced. The article will explain the science of crossing over and gene mapping. Moreover, it will discuss the importance of crossing over and gene mapping.
To understand crossing over, it is important to understand the main concepts of meiosis.

1. What is Meiosis?

Crossing over is a genetic process where the swapping of genetic material occurs. The process occurs during meiosis, a process of cell division in sexually reproducing living organisms. Meiosis takes place in two phases where a single chromosome divides into two that further divide into four during germ cell division, resulting in four cells. These four cells contain copies of the single chromosome that initially started the process.
During meiosis, the parent chromosomes are present in the form of two single-stranded chromosomes. The two strands are replicated to form two double-stranded chromosomes. These chromosomes then transfer into different cells during the cell division of germ cells.

2. What is Crossing Over?

While meiosis is taking place and chromosomes are assembling to form replicated double-stranded chromosomes, the crossing over takes place. The parent chromosomes align in a way that the DNA on them swap over/crosses over each of them. This crossing over is the reason for genetic variations among the offspring of living organisms. This is why the importance of crossing over is studied to study the genetic variation among living organisms.
The figure elaborates on the process of meiosis and how crossing over takes place during the process.

3. What is the role of Gene Mapping in Crossing Over?

Gene mapping is a process used to study the location of genes on chromosomes. There is a proper physical amp of DNA that locates the genes on chromosomes. This is used to study the probability of genetic transfer from parents to offspring. Over the years, many methods have been developed to study gene maps accurately. After years of research, the current most accurate method that is used for this purpose is through studying genome sequence. Many advanced computer programs have been established to study gene mapping and identify these genes.
Because of the importance of crossing over, much attention was given to developing computer programs and systems to study it accurately. Crossing over is studied in genetic mapping to understand and observe the order of genes on chromosomes and their distance. Scientists say that the genes that are closer to each other are more likely to be crossed over on the same chromosome and hence can be inherited together. However, cross-over frequency will be greater in genes that have more distance between them.

4. Importance of Crossing Over for Living Organisms

Small biological phenomena of crossing over taking place during meiosis have many big consequences on the human race.

a) Brings Variation in Genetic Makeup

This random shuffling of genes on chromosomes, occurring during gamete formation, holds significance in bringing variations in the gene makeup of offspring. This makes the offspring genetically different from their parents or siblings.

b) Bring Diversity to the Gene Pool

Due to crossing over, a gene pool of, let’s say a certain ethnic group, will have diversity. This diversity can be seen in the form of different physical or characteristic traits among individuals. If you see different-looking people or people having distinct appearances despite belonging to the same ethnic group, this is because crossing over has been doing its work properly for those individuals.

c) Low Chance of Genetic Diseases and Deformities

It is a well-known fact that the absence of genetic variation in a genetic line can eventually lead to deformities and genetic diseases in the family line. Therefore, cousin marriages are illegal in many parts of the world and are frowned upon in another part of the world. Without frequent crossing over, the population inherits harmful traits, which reduce their fitness, physical, and mental health.

d) Increase Population Survival Rate

With the variations in the genetic makeup of the gene pool, the chances of inheriting deformities and diseases decrease in a population. This increases the survival abilities of organisms and increases their general fitness. During a coronavirus-induced pandemic, the world observed the significance of a strong and healthy immune system. The weaker immunities tend to suffer more at the hands of coronavirus. This once again highlighted the importance of crossing over and its positive effects on the health of living organisms.

5. Importance of Crossing Over for Evolution

Crossing over serves a bigger purpose than only catering to living organisms’ biological variation, that is evolution. The importance of crossing over is undeniable in the process of evolution.

a) What is Evolution?

Evolution refers to the process of change that occurs over a period of several generations. To be more precise, evolution means the change that occurred in the traits or characteristics of species over many generations. This change can either be an adaptation of a new trait, or the elimination of a previously present trait. Evolution can also lead to changes in the physiology of living organisms. According to Darwin’s theory of evolution, it occurs through the process of natural selection. Even a small change can take up to years or centuries. When the genes are passed onto offspring from the parents, over successive generations, change occurs gradually in these generations based on the gene pool.

b) New Physiological Traits

The crossing over can often lead to the formation of new physiological changes in the living organisms if it occurs in successive generations.

c) Elimination of Unused Organs

As horrible as it sounds, the body organs that are f no use to living organisms or have not been in use for hundreds of years can lose their functionality in the body. Appendix in human beings is the result of evolution over years. Moreover, many such examples can be found in animals and plants.

d) Breeding New Species

This may not occur in humans and bigger animals, but many species of plants and microorganisms can form a new specie, all together, after years of successive mutation in the gene pool.

6. Importance of Crossing Over for Genetics and Palenteologist

People or scientists who study genetics are called geneticists, whereas; scientists who study fossils are called paleontologists. There is no doubt that the process of crossing over must hold immense importance for them, but how?

a) Importance of Crossing Over for Geneticists

The job of a geneticist is to study genes and their history. This includes gene mapping as well as linking the genetic history of one specie with another. This way they can find out about the inter-species and intra-species genetic variations.

Moreover, geneticists can also experiment with the genetics of living organisms to study the genetic basis of diseases. Once this code is cracked, they can formulate treatments based on the genetic mutation to eliminate genetic diseases among humans and other living organisms. Although this seems far-fetched, with the current technological advancements in all areas of life, anything can become possible in the future.

b) Importance of Crossing Over for Palenteologist

Paleontologists study fossils of organisms. These fossils can be from recent organisms or organisms that have become extinct centuries ago like dinosaurs. Gene mapping can help them study the crossing over the history of these fossils. This is how they can classify the fossils into different kingdoms or plants and animals based on their physiological traits.

8. Conclusion

Although crossing over may seem like a complex process but it cannot be ignored. Because the importance of crossing over may change how we see the future, one day.