|MadSci Network: General Biology|
A vulture is a bird of prey in that it primarily consumes meat. Raptors are generally considered to be birds that kill their prey, which would leave out vultures as they eat carrion (as will other types of omnivorous birds like crows and ravens). This definition of raptor would include owls as well as falcons, hawks, and eagles. So, in general, birds that wre considered "raptors" are not necessarily closely related at all. This is because "raptor" is not a taxonomic grouping. Instead, it is more like grouping things by color or size rather than true relatedness. An attempt to measure genetic relatedness and use it as a basis for taxonomic classification was performed in the 1980's by Charles Sibley and the members of his lab. They used a technique called DNA-DNA hybridization to measure an overall level of genetic similarity among differnet groups of birds. They found many relationships that were quite different from long-held views of avian classification. Their classification of vultures was been extremely controversial. Sibley and his colleagues found that Old World (Europe, Asia, and Africa) and New World (North and South America) vultures are not each others closest relatives. Other genetic work appears to support this controversial hypothesis but no consensus has yet been reached.
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