Branches of science much as it involves a clearly biological aspect. While biology remains the centerpiece of life science, technological advances in molecular biology and biotechnology have led to a burgeoning of specializations and new, often interdisciplinary, fields. "Biology" is the branch of natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines. Zoology, occasionally spelled zoölogy, is the branch of science that relates to the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both
Four Branches of the Mabinogi several tale episodes in a sequence, and each Branch is titled with the name of a leading protagonist. These titles are Pwyll, Branwen, Manawydan and Math, but this is a modern custom: the Branches are not titled in the mediaeval manuscripts. Only one character appears in all four Branches, Pryderi, though he is never dominant or central to any of the Branches. "Pwyll Pendefeg Dyfed", "Pwyll Prince of Dyfed", hunting on his own land, meets the shining Cŵn Annwn or "Hounds of Annwfn", and takes another man's kill, a stag, for himself. Arawn, the king of Annwfn, is greatly offended.