WANI Dictionary

Evolution

Evolution is genetic change in a population over time.

Definitions in the literature

• (1) the descent of modern organisms, with modification, from preexisting life-forms; (2) the theory that all organisms are related by common ancestry and have changed over time; (3) any change in the genetic makeup (the proportions of different genotypes) of a population from one generation to the next [1].
• change in a line of descent [2].
• Genetic change that takes place in a group of organisms [3].
• The gradual process by which the present diversity of plant and animal life arose from the earliest and most primitive organisms, which is believed to have been continuing for at least the past 3000 million years [4].
• the process of gradual change in a population or species over time [5].

Definition [4] is clearly inappropriate since the description only mentions plants and animals. Other organisms also evolve. In definition [5], “gradual” is ambiguous - does this mean 10 generations, 100 generations, or more? If this means 10 generations, genetic changes fixed in a population within 5 generation are not “evolution”? No need to add this word to the definition.