Slime molds or mycetozoans, were once thought to be fungi because, like fungi, they produce fruiting bodies that aid in spore dispersal. However, the resemblance between slime molds and fungi appears to be another example of evolutionary convergence. Molecular systematics places slime molds in Amoebozoa and suggests that they descended from unicellular ancestors. Slime molds have diverged into two main branches, plasmodial slime molds and cellular slime molds, distinguished in part by their unique life cycles. Plasmodial slime molds are brightly colored, often yellow or orange. At one stage in their life cycle, they form a mass called a plasmodium, which may grow to a diameter of many centimeters. The life cycle of the protists called cellular slime molds can prompt us to question what it means to be an individual organism. The feeding stage of these organism consists of solitary cells that function individually, but when food is depleted, the cells form an aggregate that functions as a unit.