Natural selection is a fundamental mechanism of evolution by which organisms better adapted to their environment tend to survive and reproduce more successfully than others. This process leads to changes in the traits of populations over generations

How Natural Selection Works

Key steps in natural selection can be summarized as VISTA:

• Variation: Within any population, individuals vary in traits such as size, color, or behavior. These variations often arise from random mutations or genetic recombination

• Inheritance: Many traits are heritable, meaning they can be passed from parents to offspring through genes

• Selection: Because resources are limited, not all individuals survive or reproduce equally. Those with traits that provide an advantage in their environment (e.g., better camouflage, stronger claws, or more attractive mating displays) are more likely to survive and leave more offspring

• Time: Over many generations, the advantageous traits accumulate in the population, making it better adapted to its environment

• Adaptation: The population evolves as these beneficial traits become more common, resulting in organisms that are increasingly suited to their ecological niches

Additional Details

• Natural selection acts on phenotypic differences (observable traits) that affect an individual's survival and reproductive success, known as evolutionary fitness

• It is a non-random process where the environment "selects" for traits that increase reproductive success, but there is no conscious intent or purpose behind it

• Natural selection can lead to microevolution (small changes within a species) or macroevolution (formation of new species) depending on the scale and nature of environmental changes

• Examples include the peppered moth in industrial England, where darker moths became more common due to better camouflage on soot-darkened trees, and finches on the Galápagos Islands, whose beak shapes changed according to available food sources after droughts

In summary, natural selection is the process where heritable traits that enhance survival and reproduction become more common in successive generations, driving the evolution and adaptation of species to their environments