Why bird can fly and pinguin can swim?
There are other birds that ‘fly’ underwater in the same way as Penguins – the auk (Alcidae) family found in the northern hemisphere has evolved to fit a similar environmental niche to Penguins, but most of these retained the ability to fly in air as well as under water (the exception was the Great Auk which man hunted to extinction). This videos of Guillemots (known as Murres to Americans) shows them in flight, and ‘flying’ under water; http://www.youtube.com/watch?v=iQkNXY-zV… (The film shows both Brunnich’s Guillemots/Thick-billed Murres and Common Guillemots/Common Murres). Compare this with video of Penguins flying under water; http://www.youtube.com/watch?v=6wWqkdvat… Like Cal King says, the switch to swimming didn’t take much because it uses the same anatomy as flying – Penguins just evolved to become better at swimming, a
