Keel (bird anatomy) keel; and ratites (from "ratis", "raft" — referring to the flatness of the sternum), having a subtle keel structure or lacking one entirely. However, this classification has fallen into disuse as evolutionary studies have shown that many flightless birds have evolved from flighted birds. The current definition of Carinatae now includes all extant birds. Keel (bird anatomy) A keel or carina (plural carinae) in bird anatomy is an extension of the sternum (breastbone) which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a
Scientific controversy how fast is it occurring and how to model it which is what is being researched and debated. It is important to distinguish between these two so that the real scientific issue does not get missed.[1] Scientific Debate- Scientific debate is based on evidence and factual information. Because of this, only experts are typically qualified to debate. The exclusion of non-scientist participants in debates causes a struggle for recognition of other significant issues such as economic concerns or cultural value of the environment. Scientific Controversies & Education- Scientific Controversies influence education more than one would expect. Scientific issues relating to