Modern birds lack teeth. Form a hypothesis to explain why this characteristic evolved...HELP!!?

Answer 1

Modern birds lack teeth because their beaks, though they have a bone center, are coated in keratin instead of ectoderm. So they can't build teeth, essentially.

It was probably an ecologically driven developmental switch, as keratin might be more resistant for a lot of bird lifestyles--if you are cracking nuts all day, it'd possibly be more resistant than teeth. Also, a beak works better than teeth would for nabbing insects out of the air.

Answer 2

Think about this: the one thing that defines most modern birds is the ability to fly. They have many specializations that contribute to make their body less heavy, while providing necessary support for flight muscles and other organs (for instance, possession of air sacs, and hollow bones).

Now, primitive birds had teeth. But teeth are heavy structures, and would be hard to support in the strong but lightweight skull of modern birds. So somewhere along their evolutionary path, teeth were reduced and then lost. Birds evolved the beak, an elongated rostrum covered with a horny sheath instead (keratin is much less heavy than the mineralized material of teeth).
In modern birds, lots of different specializations have arisen from the basic beak shape.

Answer 3

Birds have beaks instead of teeth. Each type of bird has a modified beak to fit their specific needs. Like humminbirds have long skinny beaks so they can get to plant nector. Finches have small beaks used to pick up small seeds. Parrots have strong sharp beaks used to crack open nuts and fruits. Birds also have a gizzard which grinds up their food and starts digestion, so teeth are not needed/designed for birds.

Answer 4

That's the way God made them. OR they had to eat "on the fly" and chewing wsn't easy, they were swallowing everything whole and developed a gizzard to devour their food.