What Is an Adaptation?
An adaptation is any feature of an organism that increases its chances of survival and reproduction in its particular environment. Adaptations develop over many generations through natural selection — individuals with helpful traits are more likely to survive and pass those traits to offspring.
Adaptations can be:
- Structural — physical features of the body (e.g. a duck's webbed feet)
- Behavioural — actions the animal performs (e.g. hibernation, migration)
- Physiological — internal chemical or biological processes (e.g. producing venom, having antifreeze proteins in blood)
Adaptations to Hot, Dry Environments
Animals in deserts must conserve water and stay cool:
- Camels have humps storing fat (not water) for energy; their kidneys produce very concentrated urine; they can lose 25% of their body weight in water without dying
- Fennec foxes have enormous ears — blood vessels on the surface of the large ears radiate excess heat
- Kangaroo rats never drink water; they get all moisture from seeds they eat
Adaptations to Cold Environments
Polar animals need to retain heat:
- Polar bears have hollow fur shafts that trap air and insulate; thick fat (blubber) under the skin; black skin to absorb heat
- Penguins huddle together, rotating the outside birds to the warm centre; their feathers are dense and waterproof
- Arctic foxes change colour from brown in summer to white in winter (camouflage), and have thick fur that acts as insulation
Adaptations for Hunting and Defence
| Animal | Adaptation | Purpose |
|---|---|---|
| Cheetah | Long legs, flexible spine | Speed for hunting |
| Chameleon | Colour change | Camouflage / communication |
| Hedgehog | Sharp spines | Defence against predators |
| Electric eel | Electric organ | Stun prey, self-defence |
| Giraffe | Long neck | Reach high leaves |
The Arctic fish (Notothenioidei) have special antifreeze proteins in their blood that prevent ice crystals from forming. Without this physiological adaptation, their blood would freeze in temperatures below 0 °C.
When you see an unusual feature of an animal, ask: "What problem does this solve?" Almost every unusual feature of an animal is an adaptation that helps it survive, find food, find a mate, or avoid predators.
Real world: Camel as a desert animal
Camels are used for transport in deserts because their bodies are perfectly adapted to heat and lack of water. Their humps store fat for energy during long journeys, and their kidneys conserve water so efficiently that they can go days without drinking. Tourists who ride camels in Saharan or Arabian deserts are directly relying on these structural and physiological adaptations.
Real world: Duck feet for swimming
A duck's webbed feet are a classic structural adaptation. The skin between the toes creates a paddle that pushes water backwards, propelling the duck forward. You can watch this any time ducks swim on a pond in a park — the webbing is visible when the duck lifts its feet out of the water.
Real world: Hedgehog spines as defence
Hedgehogs curl into a ball when threatened, using their sharp spines to protect themselves from foxes and badgers. This behavioural and structural adaptation is something you might see in your garden at night. A hedgehog's spines are modified hairs made of keratin.
Where do you see this in real life? Animals in your local area are all adapted to their environment. Notice how birds' beaks differ — thin pointed beaks for insects, broad flat beaks for water, hooked beaks for meat. Each beak shape is a structural adaptation shaped by millions of years of natural selection.