|Date||Mar. 2nd 2011|
|Previous||Compass and Straightedge|
Herpetology is the 867th xkcd comic.
Ornithology is the branch of zoology that concerns the study of birds, and herpetology is the branch that concerns the study of amphibians and reptiles.
At the ornithology conference, the ornithologist is arguing that the herpetology field is bogus because amphibians and reptiles form together a polyphyletic group, which means that their last common ancestor is not part of their group. While they may look similar (like salamanders and lizards) they're actually quite distant on the phylogenetic tree and as the ornithologist points out, birds are more closely related to reptiles than are amphibians, since birds evolved from small feathered dinosaurs like Velociraptors. The phylogenetic tree behind the speaker clearly shows this.
While we would expect the herpetologist to counter with a another scientific argument, she instead uses a similar phylogenetic tree to "prove" that ornithologists are closely related to douche-bags.
"Birds are Aves, which is part of the clade Theropoda, which is in Saurischia, which is in Dinosauria. Those birds outside our windows are dinosaurs. We can clear out the rest of our brains because we now have the best fact."
Quoting the phylogenetic taxonomy of birds, Randall reminds us that since birds evolved from dinosaurs, they are technically dinosaurs, which is a cool thing.
Usually birds aren't considered dinosaurs because the traditional depictions of dinosaurs excludes birds, which makes it a paraphyletic group. However, if you consider that all descendants of dinosaurs are dinosaurs, making dinosaurs a monophyletic group, then birds are dinosaurs.