Are elephants more closely related to pigs or to cows?

Who's asking: Patrick Miller, Jacksonville, FL

Actually, neither. While elephants, pigs and cows are all mammals, elephants belong to their own lonely order, Proboscidea, which includes elephants, mammoths, and several other species that are now extinct.

Biologists put animals together according to what they have in common, and at one time they thought that elephants' thick skin was similar to the skin of pigs, so the two species must be related. As they looked more closely, however, they saw that pigs and elephants don't really have that much in common. Now taxonomists believe that the two living sets of animals most closely related to the elephant are the hyrax and the sea cow ("sirenians" -- isn't that a great name? -- manatees and dugongs).

The idea that elephants might be related to manatees makes some sense. But hyraxes?











At first glance, one of these things is not like the others. But since 1945, taxonomists have placed the three types of animals in a superorder called Paenungulates, whose distinguishing feature has something to do with the amino acid sequences in their red blood cells.

I'm guessing they don't schedule many family reunions, though.






In other news, it has come to my attention that this is National Delurking Week in Blogworld. I've already done my part on another site, commenting on a forum I visit often but never post to -- and immediately getting into a snarky argument with a frequent poster. Sometimes it's best just to lurk... but today and tomorrow, if you visit here often and never comment, won't you just sign in and say who you are and where you're visiting from? I'll be fascinated. Thanks.