Adaptations are heritable traits-whether behavioral, structural, or physiological-that have evolved through natural selection to help an organism survive and reproduce in its environment. They result from genetic variations that confer advantages in a specific environmental context, leading to greater reproductive success over generations

. There are three key meanings of adaptation in biology:

• Physiological adjustments an organism makes to its immediate environment (e.g., changing metabolism with altitude) - these are short-term and not inherited.
• The evolutionary process by which populations become better suited to their environment through natural selection.
• The specific features or traits that enhance an organism's fitness in its habitat, such as camouflage, specialized body parts, or behaviors

Examples include:

• The dark coloration of peppered moths during the Industrial Revolution, which helped them blend into soot-darkened trees and avoid predators.
• The thick fur and fat layers of polar bears, which provide insulation in cold climates.
• The increased red blood cell production in humans living at high altitudes to cope with low oxygen levels

Adaptations differ from acclimatization (temporary physiological changes within an individual's lifetime) and learning (behavioral changes), as adaptations are inherited and result from evolutionary processes

. In summary, adaptations are evolved traits that improve an organism's ability to survive and reproduce in its environment, shaped by natural selection acting on genetic variation over many generations