Living creatures can adapt radically to suit their environment during their lifetimes, but such adaptations are not reflected in their DNA and therefore are not passed on genetically. Only recombination (during sexual reproduction) and mutation cause genetic change.
The idea that deliberate adaptations become hereditary is the central idea of a rival theory to Darwin's, namely that of Lamarckian evolution. This theory actually is the way creationists tend to think of Darwinian evolution: unsupported by the evidence, discredited by contrary evidence, and almost entirely dismissed by the scientific community.
That said, Darwinian evolution does allow for some developments that might appear Lamarckian in nature. While deliberate adaptations are not passed on genetically, they can be passed on by instruction and example. If a new skill is deliberately taught to the young for many generations, it may actually affect the selection process; mutations which benefit that skill may be favoured. Therefore it's possible for adaptations to eventually be reflected genetically, but only in a roundabout way.