From The Art and Popular Culture Encyclopedia
An obligation is a requirement to take some course of action. It can be legal or moral. There are also obligations in other normative contexts, such as obligations of etiquette, social obligations, and possibly the In terms of politics, obligations are requirements that are to fulfill. These are generally in the form of legal obligations, which incur a penalty for lack of fulfillment, although certain people are obliged to carry out certain actions for other reasons as well, which can be due to tradition or social reasons. Obligations vary from person to person, for example, a person holding a political office will generally have far more obligations than an average adult citizen, who themselves will have more obligations than a child. Obligations are generally granted in return for an increase in an individual’s rights or power.
Common obligations of citizens include a requirement to participate as a juror if called upon and to pay taxes, which is seen as a return for the right to participate in the electoral process and the financial and physical protection by the state. Another example, though not a common law obligation, is the US Constitutional requirement to participate in a census every ten years, which, like many legal obligations, often incurs a fine if not completed.
The term obligate can also be used in a biological context to refer to species which must occupy a certain niche or behave in a certain way in order to survive. In biology, the opposite of obligated is facultative, meaning a species is able to behave in a certain way and may do so under certain circumstances, but that it can survive without having to perform this certain behavior. For example, species of salamanders in the family Proteidae are obligate paedomorphs, whereas species belonging to the Ambystomatidae are facultative paedomorphs