Evolución Biológica: Selección Natural y Adaptación

Study Notes

Natural Selection

Definition: The process by which individuals with certain traits that are better suited to their environment are more likely to survive and reproduce, passing those traits on to their offspring.
Key components:
- Variation: There must be genetic variation within a population.
- Heritability: The traits must be heritable, meaning they are passed down from parents to offspring.
- Differential reproduction: The environment affects the reproduction of individuals with different traits.
Mechanisms:
- Survival: Individuals with advantageous traits are more likely to survive.
- Reproductive success: Individuals with advantageous traits are more likely to reproduce.

Evolutionary Adaptation

Definition: The process by which a population becomes better suited to its environment over time.
Types:
- Structural adaptation: A physical change in an organism, such as the development of wings.
- Behavioral adaptation: A change in behavior, such as migrating to a new habitat.
- Physiological adaptation: A change in the internal functions of an organism, such as the ability to regulate body temperature.
Examples:
- Peppered moths: Prior to the Industrial Revolution, the moths had a light coloration, but with the increase in air pollution, a dark-colored morph became more common, as it was better camouflaged on dark-colored tree trunks.
- Antibiotic resistance: Bacteria that are resistant to antibiotics are more likely to survive and reproduce, passing on their resistance to their offspring.

Species Variation

Definition: The differences between individuals within a species, which can lead to the formation of new species.
Causes:
- Genetic drift: Random events, such as natural disasters or genetic mutations, that alter the gene pool.
- Gene flow: The movement of individuals with different genetic traits into a new population.
- Mutation: Changes in the DNA sequence of an individual.
Types:
- Continuous variation: Traits that vary continuously, such as height or skin color.
- Discontinuous variation: Traits that fall into distinct categories, such as blood type.
Importance:
- Species variation is the raw material for evolution, as it provides the genetic differences that can be acted upon by natural selection.
- It allows species to adapt to changing environments and survive in the face of challenges.

Description

Aprende sobre los conceptos fundamentales de la evolución biológica, incluyendo la selección natural, adaptación evolutiva y variación de especies. Explora los mecanismos y tipos de adaptación, así como la importancia de la variación en la evolución de las especies.