Adaptations. Laboratory work 4

Adaptation is the fitting of an organism’s structure, function, behaviour and way of life to a particular environment; it secures survival, competitiveness and reproduction. Adaptations are a result of natural selection: of random hereditary changes, those suited to the environment are kept and accumulate over generations. Morphological adaptations concern body shape and colour: the body of a bird suited to flight and of a fish to swimming; protective colouring (a desert lizard sand-coloured, hares and ptarmigans turning white in winter); camouflage (a stick insect resembles a twig, the Kallima butterfly a leaf); warning colouring – bright colour in protected animals (wasp, ladybird) warns predators; mimicry – an unprotected species resembling a protected one (some flies resemble wasps). Physiological adaptations concern metabolism and functions: the camel’s economy of water, hibernation, salt tolerance in plants. Behavioural adaptations: bird migration, hoarding of food by animals, playing dead. No adaptation is absolute; they are relative: useful only in that environment, and if the environment changes the benefit can disappear (a white hare is at risk if snow does not come); predators also adapt; and mimicry fails if the predator learns. This relativity shows that adaptations are a result of selection, not of purposeful design.