Each specimen consists not only of the plant or animal but also of a record of the date, locality, habitat, and often other data about the organism. Because the environment is changing due to natural events and human activities, the collections serve as irreplaceable historical records of our natural heritage. Understanding the distribution, ecology, and conservation of our living natural resources depends on these records. The specimens also prove indispensable for identifying organisms for other governmental agencies and for the public. Many species look very similar, so distinguishing a beneficial insect from a pest, or an endangered plant from a common weed, can be difficult without comparative material.
Specimens are a useful tool for teaching about the diversity of life.
Finally, collections form the basis for our research programs in systematics, whereby we strive to understand the evolutionary patterns and processes responsible for the biodiversity of our state and the world beyond. They contain over 7,700,000 individual items and continue to grow, with over 112,000 specimens added this year through staff activities and gifts from researchers at other institutions. All major groups of organisms are represented. Our particular strengths are in insects, fishes, mollusks, crustaceans, annelids, amphibians and reptiles, vascular plants, and fungi. Though most of the specimens are from Illinois, organisms do not respect political boundaries, and the Survey's collections contain plants and animals from throughout North America and from other parts of the world.