This is a study of the evolutionary history of a group of South american passerine birds,t he subfamily Furnariinae or ovenbirds. During geological history, when South America was isolated from the other continents by water barriers, this group underwent a remarkable adaptive radiation into a variety of ecological roles which, in other parts of the world, are filled by members of many other families. The comparative anatomy of the hindlimb musculature and external morphology, including the bill, nostrils, feet, and tail, will be studied by dissection and observation of museum specimens. anatomical variations will be described and illustrated, and the direction in which characters evolved will be determined. Using this information the phylogeny of pattern of common descent will be generated by computer. This will reveal how different groups, evolving separately, have developed adaptation for similar ways of life in parallel. From the conclusions reached, the evolutionary history of the ovenbirds will be clarified, the classification will be revised, and the insight will be gained into the mechanisms and limitations of the evolutionary process.
