Video Contents: Introduction To Evolution Theory:

 

In biology, evolution is change in the genetic material of a population of organisms from one generation to the next. Though changes produced in any one generation are small, differences accumulate with each generation and can, over time, cause substantial changes in the population, a process that can culminate in the emergence of new species. Indeed, the similarities amongst species suggest that all known species are descended from a common ancestor (or ancestral gene pool) through this process of gradual divergence.

 

The basis of evolution is the genes that are passed on from generation to generation; these produce an organism's inherited traits. These traits vary within populations, with organisms showing heritable differences (variation) in their traits.

 

Evolution itself is the product of two opposing forces: processes that constantly introduce variation, and processes that make variants either become more common or rare.

 

New variation arises in two main ways: either from mutations in genes, or from the transfer of genes between populations and between species.

 

Two major mechanisms determine which variants will become more common or rare in a population.

 

One is natural selection, the other is genetic drift. Genetic drift is an independent process that produces random changes in the frequency of traits in a population. Genetic drift results from the role that chance plays in whether a given trait will be passed on as individuals survive and reproduce.

Theory Of Evolution

Back

Next