The gradual change in the genetic makeup of a population over time.
This change can be driven by various factors, including:
* Natural Selection: The process where organisms with traits better suited to their environment are more likely to survive and reproduce, passing those traits on to their offspring.
* Genetic Drift: Random fluctuations in the frequency of genes within a population.
* Mutation: Changes in the DNA sequence that can introduce new traits.
* Gene Flow: The movement of genes between populations.
Here's a more detailed breakdown:
* Evolutionary change occurs at the population level, not the individual level. An individual organism doesn't evolve, but rather the population as a whole undergoes genetic changes over generations.
* Evolution is a gradual process that takes place over many generations. It's not something that happens overnight.
* Evolution is driven by natural selection, which acts on the variation that exists within populations. This variation comes from mutations, gene flow, and genetic drift.
* Evolution is a continuous process that is still happening today. New species are constantly evolving, and existing species are constantly adapting to their changing environments.
In essence, biological evolution is the mechanism by which life on Earth has diversified and adapted to its various environments over millions of years. It is a cornerstone of modern biology, providing a framework for understanding the history and diversity of life.
