Microevolution

Natural selection, or evolution, is the process by which a species’ features change throughout multiple generations. From small-scale changes like an increase in the frequency of the gene for dark wings in beetles from one generation to the next to large-scale ones like the development and radiation of the dinosaur lineage, evolution comprises changes on a wide range of dimensions. 

These two extremes serve as illustrative cases of both macro- and microevolution. Microevolution takes place on a limited scale (within a single population), whereas macroevolution takes place on a scale that extends beyond the bounds of a single species.

Microevolution

Gene frequency changes over time are referred to as macroevolution. Different gene forms are known as alleles. The relative frequency of a certain allele at a given locus that is seen in a population is known as allele frequency. The frequency of alleles is frequently expressed as a percentage. Ecological geneticists track these changes in the wild, while population geneticists mathematically analyze the microevolutionary processes. All living organisms benefit from microevolution, which happens naturally as a result of adaptation. It is also crucial to keep in mind that microevolution may result in speciation and act as a raw material for macroevolution, which is brought on by the accumulation of alterations from macroevolution. As a result, it may be inferred that macroevolution and microevolution both follow comparable processes, with temporal scale acting as the differentiator. Compared to macroevolution, this change happens more quickly in terms of evolution. 

Selection, mutation, genetic drift, and gene flow are the processes that are responsible for the change that microevolution involves.

History of Microevolution

Robert Greenleaf Levitt, a botanist, coined the phrase “microevolution” for the first time in the year 1909 in the publication Botanical Gazette. An allele is a certain gene’s variant form that can be found at particular chromosomal sites. In layman’s terms, we can define it as a physical characteristic that represents a population of subtle and indistinct alterations. However, the descendants are unaffected by these modifications.

Causes 

Different causes for the microevolution are:

Mutations

A mutation is a change in the DNA’s sequence brought on by radiation, chemicals, viruses, replication, and meiosis, among other factors.

• During the polymerization of the second strand, errors are introduced into the DNA replication process. If a mutation occurs inside a gene’s protein-coding region, it may have an impact on the phenotype of an organism.
• There are numerous kinds of mutation, or changes in DNA sequences, including those that have no effect on a gene, affect the gene’s product or stop a gene from working.
• A mutation may result in a significant amount of DNA duplication due to genetic recombination.

Genetic Drift

Genetic drift is the shift in an allele’s relative frequency within a population. Small populations may be more affected by genetic drift than large populations, and vice versa.

• The alteration in allele frequencies throughout time is the result of evolution. Alleles may fully vanish as a result of this.
• Although the environment or adaptive pressures may not regulate the changes brought on by genetic drift, they might support the maintenance of reproductive success.

Gene Flow

Gene flow refers to the movement of genes among populations of the same species.

• Migration, breeding, and the exchange of pollen grains are examples of gene flow within the same species. Horizontal gene transfer and the development of hybrid creatures occur between the species.
• Emigration and immigration both have the potential to alter allele frequencies by introducing and removing genetic material from the gene pool, respectively. Reproduction is impeded by two diverging populations; gene flow can introduce genetic variations and cause a slowdown in the process.
• A mule is a hybrid created when the gametes of horses and donkeys combine. However, due to the presence of many sets of chromosomes that do not properly link during the meiotic process, this hybrid is typically infertile. However, hybridization is a crucial method of speciation in plants because, in contrast to animals, plants respond to polyploidy more readily.
• Horizontal gene transfer is the transfer of genetic material from one creature to another that is not its progeny.

Selection

The process by which an organism’s heritable features enable it to survive and reproduce in a population across many generations.

• If selection happens by chance, it is called natural selection; if it is influenced by human decision, it is called artificial selection. The major factor in selection, nevertheless, is natural selection.
• Phenotypes are subject to natural selection.

Examples

Herbicide resistance, pesticide resistance, antibiotic resistance, and other types of microevolutions resulting from natural selection are all examples. The bacterial strains that have the trait of antibiotic resistance are a few more generally visible evolutionary examples of microevolution, few such examples:

1. Whiteflies’ pesticide resistance
2. Mosquito resistance to DDT
3. HIV strains are becoming immune to antiviral drugs
4. Penicillin-resistant forms of gonorrheal bacteria

Difference between Microevolution and Macroevolution

FAQs on Microevolution

Question 1: Define microevolution and macroevolution.

Answer: 

The alteration in allele frequencies that takes place gradually within a population is known as microevolution. Macroevolution is typically defined as the development of substantial structures and features that go far beyond the intraspecific variation found in microevolution.

Question 2: Mention the name of evolution which create new species.

Answer: 

Macroevolution creates new species as the genetic structure has undergone various additions and deletions.

Question 3: Mention the name of the process of microevolution.

Answer: 

Name of the process of microevolution:

1. Mutation
2. Genetic drift
3. Gene flow
4. Selection 

Question 4: State the examples of microevolution.

Answer: 

Examples of microevolution: New strains of flu viruses, the peppered moth.

Question 5: What is mutation?

Answer: 

A mutation is a change in the DNA’s sequence brought on by, among other things, radiation, materials, viruses, replication, and meiosis.