Introduction
What is evolution?
The change in the characteristics of a species over several generations is known as evolution. It is also defined as the process that leads to changes found among species or organisms observed over several generations.
Genetic Variation
It means differences at chromosome levels within the members of a population and whatever is encoded in genes is passed from one generation to another. This helps in giving rise to organisms with better suitability. Evolution happens when many individuals show considerable genetic differences among themselves instead of only one or a handful of organisms, proving that evolution is a long process.
For example: Let us look at the evolution of vertebrates. A cladogram is a diagram used to represent a hypothetical relationship between animals which is called a phylogeny. The organisms present on the earth are related to each other by having common ancestors with the same traits. We can analyse the relationship between the microorganisms by analysing their characteristics.
A population of species experiencing genetic variations is in the same gene pool. A gene pool is a collection of different genes within an interbreeding population. A gene pool is said to evolve if the allele frequencies change over time to another generation. Several mechanisms lead to changes in the allele frequencies of the gene pool. These mechanisms of variation in evolution are classified as follows:
- Mutation: The random transformation of genes and alleles is known as mutation.
- Natural selection: The differential success in the survival and reproduction of organisms is known as natural selection.
- Selective mating: If the individuals preferentially meet with the subsiding population, such as their close relatives, inbreeding and random mixing of the gametes do occur, and genotype frequencies change. Sexual selection can result in sexual dimorphism. In simple terms, certain characteristics increase the chances of mating.
The Importance of Variation
At the time of copying, when there is a change in DNA information, the proteins formed are different, and hence their variation occurs from the parent species, which is the basis of evolution. Some variations occur each time a DNA is copied, and therefore the DNA copies are similar but not identical. Hence, the offsprings’ DNA is similar to those of the parents but not equal. The population of organisms fills up due to reproduction. Various external factors like changes in temperature or weather, water level, or a meteorite hit can affect the population, and drastic changes can even result in eliminating the entire population. However, there are still some changes that few individuals may survive. These variations play an important role in the survival of a species in unfavourable conditions and prevent the wiping out of the species.
Why do organisms not create identical copies?
Every solo life starts with the basic unit known as a cell on the earth. The cell consists of the nucleus that carries the information of the genetic formation for the offspring or to the next generation in the form of deoxyribonucleic acid or DNA. DNA replication is known as the elementary process of reproduction. The replica of DNA starts the division of the cell. However, the model is different from the original DNA. DNA is not a built-up organism; the cells get divided into two.
During the confirmation of gametes, the process of meiosis occurs. Ultimately, DNA is separated from the main parent cell by recombination and crossing over. A variation in the DNA data denotes its starting stage of interpretation. The changed DNA dupe will decode with the proteins far different from the initial ones. The non-similar proteins cause variation in that organism. The inherited body design from its parent would not be considered presently. This variation is slow and drastic. The riff at the time of reproduction is the inbuilt capacity that leads to the direction of the evolution of the species on the earth.
Hence, these cells look like the DNA material with their body design and physiology; but are still not similar and identical.
Conclusion
We have learned the importance of variation in living beings. Evolution is defined as the process of the changes found among species or organisms observed over several generations. Genetic variation within a population is passed from one generation to another helping in the formation of new species.