Final answer:
The two main components of life history theory are reproductive strategies and the allocation of resources for various life activities like growth, maintenance, and reproduction.
Step-by-step explanation:
The two main components of life history theory are the reproductive strategies and the allocation of resources for growth, maintenance, and reproduction. Life history traits, which are shaped by natural selection, help species adapt to their environments and obtain the resources they need for successful reproduction. These traits also determine a species' position along the continuum of K-selected and r-selected strategies. K-selected species allocate more resources to fewer offspring with higher parental care, leading to higher survival rates of young, whereas r-selected species produce many offspring with less parental care, leading to a strategy that favors quantity over the survival of individual young.