Biologists are interested in every kind of living thing. When they study
organisms in relation to atomic radiations, they enter the field of
radiobiology, which really is not a science in itself but merely a
branch of the larger interest in biology. Biologists find that atomic
energy has significance both in the study of individual organisms and in
studies of organisms in their natural communities and habitats.
[Illustration: _Skin-diving biologist collecting giant clam from coral
bottom of Bikini Lagoon in the Pacific Ocean._]
Radioactivity introduced into any community may be “taken up” by the
biological system, becoming subject to cycling in food chains or to
accumulation in plant or animal tissues. The presence of radioactivity
permits study of the workings of a system as large as an ocean, perhaps,
or of one no larger than a tree. And in each case it thus may be
possible to observe how the cycles of organic renewal are related to the
larger systems of life on earth.