grp@Unify.com (Greg Pasquariello) (12/13/90)
In article <10775@helios.TAMU.EDU>, e343gv@tamuts.tamu.edu (Gary Varner) writes: > > +---------------------------------------------------------------------+ > | Gary Varner "It's too late to die young." | > | Department of Philosophy -- Gregg Brown | > | Texas A&M University | > | College Station, TX e343gv@tamuts.tamu.edu | > +---------------------------------------------------------------------+ > > (*) Before this remark touches off another semantic frenzy like > my earlier unguarded remark about "hawks" vs. "accipiters and falcons" > (I meant the buteos, by the way, I was speaking carelessly), let me > emphasize that the vultures and condors _are_ raptors. "Raptor" is > actually a functional rather than a phylogenetic category. The owls > on the one hand and the hawk and falcon families (which includes > everything from eagles and buteos to kites and kestrels, _as_well_as_ > vultures_and_condors_) Heh, heh, heh :-) Actually, there has been some recent evidence, mostly chromosomal, that New World vultures are more closely related to storks! > are now thought to be examples of convergent > evolution: both categories of birds developed keen eyesight, strong > feet with sharp talons, and sharp, hooked beaks, because they lead > similar lifestyles (catching and killing fast moving prey). The > vultures still have keen eyesight and sharp, hooked beaks for tearing > flesh, but they have lost the strong feet the other raptors need > for catching and killing their prey. Since vultures eat carrion, they > don't need strong feet, and since they spend a lot of time on the ground > (unlike other raptors, who prefer to carry their prey into a tree or > onto a ledge to eat it, if possible), the strong grasping feet of > (say) a great horned owl would actually be maladaptive. -- --- Greg Pasquariello Unify Corporation grp@Unify.Com