Why does the lowly slime mold sacrifice itself for the good of the community?
It is often assumed that much of biology can be explained by a need to produce offspring. This concept is rooted in the theory that organisms are preprogrammed to reproduce and carry their DNA forward to future generations. So how does altruism, that is, the concept of self-sacrifice or a greater concern for the survival of others, persist throughout time? A Rice University research team funded by NSF’s FIBR program is piecing this puzzle together by studying a lowly, single-celled amoeba. The slime mold, Dictyostelium discoideum, is normally found on the forest floor nestled among the leaves. When individual Dictyostelium cells detect they are running out of food, they cooperatively coagulate to form a slug. This mobile slug searches out more suitable conditions, ultimately raising itself up on a “stalk” formed by some of the selfless siblings. Atop the stalk, Dictyostelium spores form and are released, dispersing some lucky, individual cells free to go about life while their comrades
