Descent with Modification
All living things share common ancestors and have changed over time, giving rise to the diversity of life we see today347.
Variation
Individuals within a species differ from each other due to genetic variations. These differences arise from mutations and genetic recombination345.
Natural Selection
Some variations give individuals advantages in survival and reproduction. These advantageous traits become more common in the population over generations, shaping the evolution of species3457.
Populations Evolve, Not Individuals
Evolution is a change in the genetic makeup (allele frequencies) of populations over generations, not changes within an individual’s lifetime45.
Speciation and Common Ancestry
New species arise when populations of a species become isolated and evolve independently. All species are connected through a branching tree of life, tracing back to common ancestors34.
Evolution is Not Goal-Oriented
Evolution does not always lead to "better" or more complex organisms. It is driven by adaptation to changing environments and can occur gradually or rapidly45.
Supported by Multiple Lines of Evidence
Evidence for evolution comes from genetics, fossils, anatomy, and observations of natural populations67.
In summary, evolution explains how life changes over time through genetic variation and natural selection, leading to the diversity of species from shared ancestors347.