Evolution is a process that results in changes in the genetic material of a population over time. It is the change in the characteristics of a species over several generations and relies on the process of natural selection. Evolution helps us to understand the living world around us, as well as its history. Here are some key points about evolution:

• Descent with modification: Evolution is the historical occurrence of change, and natural selection is one mechanism that can cause it. It refers to change through time as species become modified and diverge to produce multiple descendant species.

• Genetic variation: Evolution relies on there being genetic variation in a population which affects the physical characteristics (phenotype) of an organism. Changes in DNA sequences affect the composition and expression of our genes, the basic units of inheritance.

• Natural selection: Charles Darwin’s theory of evolution states that evolution happens by natural selection. Natural selection is a process that increases the frequency of advantageous alleles in a population. It results in organisms that are more likely to survive and reproduce.

• Speciation: Over a long period of time, genetic drift and the accumulation of other genetic changes can result in speciation, which is the evolution of a new species.

Evolution is not simply a matter of change over time. Many things change over time, but they aren’t examples of biological evolution because they don’t involve descent with inherited modifications. Evolutionary processes depend on both changes in genetic variability and changes in allele frequencies over time. The study of evolution can be performed on different scales, from small-scale evolution to large-scale evolution.