What birds lost

From Ineffable Island, a study of bird genetics. Phase two of four.

They are triangulating birds against lizards and mammals - since we have no dinosaurs left beside birds. They are promoting where birds lost such genes as survive among the rest of us (especially alligators?). Phase One overcounted the losses; it turns out that some far-fledged [heh] birds keep these archaisms, to the tune of 142. Phase Two still reports 498 genes not found in any birds today; most of these must have been lost at the baseline.

Losing genes allows, even forces, evolution down a different path. Some of these genes hit the throat. Where a mammal, even a singing mammal like a primate, can sing with an overtone; a songbird has lost this gene so can't. So a songbird sings purely. We may dovetail (so to speak) also with the loss of teeth.

This particular paper isn't sketching out timelines. We must go to the Island to be told when the bird diffused from the dinosaurs (150 Mya - very roundly!), let alone on what sort of dinosaur (that's coelurosaurs). Maybe that's for Phase Three. Or Four.

Science-fiction authors might consider an alien race that communicates entirely through musical notes rather than through the vowel-consonant system only sporadically infused by tone.