Human genetics is the study of characteristics inherited from parents to offsprings at the crux of it. Human inheritance does not differ in a remarkable way in other entities. Genetics studies the causes of similarities or differences observed in entities. A small segment of DNA situated in the chromosome that governs the synthesis of a protein or a trait in an entity is referred to as a gene. Genes are found in the gene locus which are specific sites on chromosomes. During the process of cell division, a gene can be replicated and carried to the next generation as a unit of inheritance. Genes can occur alternately and are referred to as an allele. Through the process of reproduction, genes are transferred to successive generations. In some cases, mutations occur which causes a significant change in the gene, altering the way in which a gene is expressed. These variations(if any) are also transferred during the process of reproduction.
Significance Of Genetics In Evolution
A few of these characteristics are favourable and are called as beneficial mutations which provide a better survival benefit to changing surroundings. Evolution of a new class of species altogether occurs when a permanent change takes place in the phenotype of an entity as a result of natural selection and competition when an environment continues to stay for longer durations incorporating better-adapted entities.
Gene mutations cause the evolution we observe. It causes a change either in the organization or amount of genetic material in a cell. Such a mutation if occurred in a gamete can be easily inherited by the emerging gamete. New alleles of genes are produced as a result of mutations and hence the variations between entities. Therefore, genes and genetic mutations play a significant role in the process of evolution.
Sources Of Genetic Variation
Genetic variations are crucial as they bring about fundamental mechanisms of evolutionary changes. Listed below are three sources of genetic variation, they are:
- Mutations are alterations in the DNA. The effect a mutation can cause may be large. Evolutionary changes, however, is contributed to several mutations over a period of time.
- New gene combinations into a population can be introduced by sex which contributes as another source to bring about variation.
- A significant source of genetic variation is the gene flow, which is the movement of genes from one to another population.
Take This Quiz
Q.1. If humans evolved from apes, why are there still apes?
A.1. Apes and humans shared common ancestors and we did not involve from apes. These common ancestors no more exist.
Q.2. Is evolution reversible?
A.2. Evolution is a continuous process and keeps moving forward. Hence natural evolution is irreversible.
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