Type specimens serve as a reference point for the naming of new species. This is useful because it allows scientists to order and classify their discoveries. Problems that occur include the duplication of specimen names as well as issues with notation and classification. Precise operational definitions that are valid and reliable can help to overcome these problems by creating systems to maintain the integrity of the process. Using your own words, provide: (a) a brief note on the key characteristics of each of the following listed below; and (b) explain what general trends in human evolution each supports. Sahelanthropus tchadensis (8 points)The Sahelanthropus tchadensis is one of the oldest species that has been found on the human family tree. The fact that it walked upright likely helped it to survive in a variety of habitats. Ardipithecus ramidus (8 points) The Ardipithecus ramidus is an early example of an ape that had both the ability for bipedal movement and tree climbing. This adaption likely had profound influences on human evolution. The find indicates that human evolution occurred in wooded areas. Australopithecus afarensis presents a genus closely related to that of the homo. It is thought to be an important ancestor of humanity. Australopithecus africanus is thought to be one of the most direct ancestors of human beings. Its build was thought to have been strikingly similar.