Re: Are vultures raptors? I.e. - is the dna categorization of birds valid?

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.