Which group of living things can move energy from consumers at the top of an energy pyramid back to producers at the bottom? *

Answer is Decomposers

In any food chain autotrophs are producers which is makes food with the help of sun energy. Primary consumers are herbivores which eat plants, and secondary and tertiary consumers are carnivores which feed on primary consumers. On the death of producers and consumers, decomposers such as bacteria and fungi, breakdown dead animal, dead plant materials and waste products from other members of the ecosystem into simple soluble nutrients. These nutrients return to the soil from dead organic matter. Thus, the living things depends on decomposition processes at the end of the chain by decomposers.  

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.