What Is Natural Selection?
Natural selection is the process by which organisms better adapted to their environment survive and reproduce at higher rates than others. First described by Charles Darwin, it is the key mechanism of evolution and explains how species change over time.
Natural selection acts on variation that naturally exists within populations. Over generations, beneficial traits become more common.
How Natural Selection Works
- Variation Exists
Individuals differ in traits such as size, strength, speed, coloration, or behavior. - Overproduction of Offspring
More organisms are born than the environment can support. - Competition for Resources
Individuals compete for food, mates, shelter, and survival. - Differential Survival and Reproduction
Those with advantageous traits are more likely to survive and reproduce. - Inheritance of Traits
Favorable traits are passed to offspring. - Gradual Change Over Time
Populations evolve as advantageous traits become widespread.
Types of Natural Selection
- Directional Selection
Favors one extreme phenotype. - Stabilizing Selection
Favors the average trait. - Disruptive Selection
Favors two extreme phenotypes.
Real-Life Examples
- Antibiotic resistance in bacteria
- Peppered moth color changes
- Beak size variation in Darwin’s finches
Natural selection explains biodiversity and adaptation across all living systems.
FAQs About Natural Selection
Is natural selection random?
Mutation is random; natural selection is not. It favors traits based on survival advantage.
Does natural selection happen quickly?
It can be slow, but microorganisms can evolve rapidly.
Is natural selection the same as evolution?
Natural selection is one mechanism of evolution.
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