Biological Science Fundamentals and Systematics is a component of Encyclopedia of Biological, Physiological and Health Sciences in the global Encyclopedia of Life Support Systems (EOLSS), which is an integrated compendium of twenty one Encyclopedias. The Theme on Biological Science Fundamentals and Systematics provides the essential aspects and a myriad of issues of great relevance to our world such as: History and Scope of Biological Sciences; The Origin and Evolution of Early Life; Evolution; Classification and Diversity of Life Forms; Systematics of Microbial Kingdom (s) and Fungi; Systematic Botany; Systematic Zoology: Invertebrates; Systematic Zoology: Vertebrates which are then expanded into multiple subtopics, each as a chapter. These four volumes are aimed at the following five major target audiences: University and College students Educators, Professional practitioners, Research personnel and Policy analysts, managers, and decision makers and NGOs.

How could life have started on Earth and how did it proceed? After a short discussion on the origin of life on Earth and the origin of the major body plans the invertebrates are presented in the order of increasing complexity by the most significant fossil representatives. In each case, the adaptive significance of the respective forms and/or structures which more or less profoundly changed the original body plan is treated in detail. In the closing chapter, some general aspects of invertebrates in evolution and palaeoecology, palaeobiogeography and biochronology are outlined.