Final answer:
Reciprocal altruism is the term used to describe altruistic behaviors between unrelated individuals, which includes behaviors based on the expectation of future rewards.
Step-by-step explanation:
The type of altruism that refers to the sacrifices an animal might make for an unrelated animal of the same species in anticipation of a later reward is known as reciprocal altruism. This concept explains altruistic behaviors between unrelated individuals. These behaviors are not altruistic in the purest sense because they involve an expectation of a future reward or benefit. An example is seen in monkey species where grooming and parasite removal are exchanged between individuals, which raises their overall fitness.
This exchange also ensures punishment for cheaters, who do not reciprocate the altruistic act, thereby sustaining the mutual cooperation within the social group. Reciprocal altruism fits within evolutionary game theory, which suggests that many such behaviors hold 'selfish' components that are designed to improve the chances of gene propagation.