1. of or relating to a trait or feature that evolved for one purpose but is now used for a different purpose; describing an organism or structure that has been repurposed through evolution.
Usage: technical term used in evolutionary biology; contrasts with 'adaptive' in that the current function was not the original selective pressure

Examples

• Feathers are often cited as an exaptive feature—they originally evolved for thermoregulation but were later co-opted for flight.
• The exaptive use of swim bladders in fish shows how structures can be modified for entirely new functions.
• Scientists study exaptive traits to understand how evolution produces novelty without requiring new genetic material.
• Bird wings are a classic example of exaptive evolution from dinosaur forelimbs.
• The exaptive nature of human language suggests it may have originated for a different cognitive purpose.