New research from scientists at UC San Diego’s Scripps Institution of Oceanography finds a tiny freshwater parasite known to cause health problems in humans defends its colonies with a class of soldiers that cannot reproduce. New research from scientists at UC San Diego’s Scripps Institution of Oceanography finds a tiny freshwater parasite known to cause health problems in humans defends its colonies with a class of soldiers that cannot reproduce. Plants & Animals Ecology Phys.org – latest science and technology news stories