So, on what finger do you wear a promise ring? In the USA and the UK, the ring finger (fourth finger) of the left hand holds the greatest significance; engagement rings and wedding rings are worn on this finger almost without exception.
In biology and ecology, extinction is the end of an organism or of a group of organisms (taxon), normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively.
Now that you understand classical and operant conditioning, let's examine a few terms that are used to describe phenomena associated with behavioral conditioning. Extinction is a term that refers to the disappearance of a conditioned response. The response weakens and eventually disappears due to removal of the reinforcement or punishment in operant conditioning or the removal of the paired stimulus in classical conditioning.