Natural Selection Examples. Natural selection is a fundamental mechanism of evolution that results in the gradual change of populations over time. It occurs when certain traits increase the chances of survival and reproduction, leading to those traits becoming more common in a population over generations. Here are 10 examples of natural selection in action:
Natural Selection Examples
- Peppered Moths: In industrialized areas, dark-colored peppered moths became more common as they were better camouflaged against polluted backgrounds, while lighter-colored moths were more easily spotted and eaten by predators.
- Galapagos Finches: Different species of finches on the Galapagos Islands developed different beak shapes over time, allowing them to exploit different food sources and adapt to their specific environments.
- Antibiotic Resistance: Bacteria that are resistant to antibiotics survive and reproduce, passing on their resistant traits to offspring, leading to the evolution of drug-resistant bacterial strains.
- Pesticide Resistance: Insects exposed to pesticides that survive due to genetic resistance can pass on their resistance to their offspring, leading to the proliferation of pesticide-resistant insect populations.
- Human Lactose Tolerance: In some human populations, the ability to digest lactose (found in milk) persists into adulthood due to a genetic mutation. This mutation provided an advantage in societies where dairy consumption was common.
- Camouflage and Mimicry: Animals that possess better camouflage or mimicry traits are more likely to survive and reproduce, passing on these traits to their offspring. For example, stick insects resembling twigs or chameleons blending into their surroundings.
- Darwin’s Finches: On the Galapagos Islands, finches with beaks that were better suited for cracking different types of seeds survived and reproduced more successfully based on the food available, leading to the diversification of beak shapes.
- HIV Resistance: Some individuals possess genetic mutations that make them resistant to HIV infection. These mutations have become more prevalent in populations with a history of exposure to HIV.
- Mimicry in Snakes: Non-venomous snakes that resemble venomous species are less likely to be attacked by predators, giving them a survival advantage and increasing the likelihood of passing on their genes.
- Climate Adaptation: Populations of animals, such as polar bears and penguins, have adapted to their cold environments through traits like thick fur, blubber, and streamlined bodies, allowing them to better survive and reproduce.
These examples demonstrate how natural selection drives the evolution of traits that enhance an organism’s survival and reproductive success in various environments and circumstances.