Question

Write down the three main concepts of the modern synthetic theory.

Answer 1

The modern synthetic theory gives importance to both mutations and natural selection. The factors involved in Modern synthetic theory can be broadly divided into three main concepts i.e. genetic variation, natural selection, and isolation.

1. Genetic variations: They are caused due to various aspects of mutation, recombination, and migration. The change in gene and gene frequencies is known as genetic variation. Genetic variations are caused by factors such as - Gene mutation, genetic recombination, gene flow, genetic drift, chromosomal aberrations.
2. Natural selection: Natural selection is the process by which better-adapted organisms grow and produce more number of offsprings in the population. It is the main driving force behind evolution. It states that the fittest organism will get selected by nature and produce more offsprings than organisms that did no adapt to the as per the conditions. It brings about evolutionary changes by favoring differential reproduction of genes that bring about changes in gene frequency from one generation to another. Natural selection invariably encourages those genes that assure the highest degree of adaptive efficiency between a population and its environment.
3. Isolation: It is the separation of the population of a particular species into smaller units that prevents interbreeding between them. A barrier that prevents gene flow or exchange of genes between isolated populations, is called isolating mechanism. A number of isolating mechanisms are operated in nature and therefore divergence and speciation may occur. The isolating mechanisms are of two types namely, geographical isolation and reproductive isolation.