The dogs' value to early human hunter-gatherers led to them quickly becoming ubiquitous across world cultures. Dogs perform many roles for people, such as hunting, herding, pulling loads, protection, assisting police and military, companionship, and, more recently, aiding handicapped individuals. This impact on human society has given them the nickname "man's best friend" in the Western world. In some cultures, however, dogs are also a source of meat.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Dogs have hunted with and done other things for people for a long time, but what is a more recent help to people they provide?
aiding handicapped individuals.