When the allele frequency in a gene pool changes over time, this indicates that a population is evolving. When this happens, the ratio or percentage of certain genes in a population is changing and not the individual organism.

A mutation occurs when there are changes in the gene structure of organisms. It may either increase or decrease the fitness of organisms. However, for mutations to be evident in an organism, it must be inherited by the offspring.

On the other hand, genetic recombination occurs during the sexual reproduction of two parents. During this process, different gene combinations or genotypes are produced. This event is similar to shuffling a deck of cards.

Lateral gene transfer occurs when the genetic material is transferred between organisms. This is not the same as transferring the genes from parent to offspring. This process usually occurs in single-celled organisms such as bacteria and plasmids.

A single-gene trait refers to a characteristic or a phenotype that is controlled by one gene. In each gene trait, it can be controlled by two or three phenotypes. For example, the gene for the cat’s fur has two alleles. One allele is responsible for the white color and the other one is for the gray color. There are only two phenotypes for this trait: white or gray fur.

On the other hand, a polygenic trait is influenced by two or more genes, wherein the traits have a wide variety of phenotypes. Height, hair color, and skin color are examples of polygenic traits.

The term fitness represents an individual’s ability to adapt, live longer and reproduce more offspring in a given environment or condition. If certain species have a high fitness, they are favored by nature. In this case, the appearance of bright orange color in the butterflies means that this trait is favored by natural selection. Eventually, the alleles that are responsible for this trait becomes more common in the butterfly population.

A mutation occurs when there are changes in the gene structure of organisms. It may either increase or decrease the fitness of organisms. However, for mutations to be evident in an organism, it must be inherited by the offspring. Once the mutation in the genes is transferred into the next generation, a new allele is added to the gene pool; hence, the genetic variation in these organisms increase over time.

Lateral gene transfer allows the bacteria to develop resistance to antibiotics and spread it between bacterial populations. When the antibiotic is introduced to a bacterial community, it kills most of the bacteria due to natural selection. However, some bacteria may have genetic mutations that enable them to resist the effects of an antibiotic. This causes them to survive and transmit the genetic information to other bacterial cells through lateral gene transfer. This process allows bacteria to transfer genes from one population into another. As a result, the next generation would evolve and develop defenses that would make them resistant to the drug.