7 wonders of the soil
Neither plant nor animal nor fungus, Dictyostelium discoideum is a cellular slime mould, a microscopic amoeba that normally lives independently in the soil, eating decaying vegetation, fungi and bacteria, and helping to maintain the balance of microflora. What makes it fascinating is its ability to turn from a single-celled organism into a multi-cellular body: when there isn’t enough food or temperatures become too low, the microscopic cells swarm together to form a single, slug-like – and often brightly coloured – blob. This blob moves towards warmth and light, sometimes harvesting bacteria from one place and carrying it to a more suitable location. When ready to reproduce, it shape-shifts into a plant-like structure with a stalk, which lifts a spore head high enough for spores to be scattered for germination. The slime mould’s ability to live as both an individual and communal organism is of interest to biologists studying organ and tissue development.