Whenever I see this picture I think of this:

| Creature | Swims | Walks | Flies |
| -------- | ----- | ----- | ----- |
| Dog      | X     | X     |       |
| Fish     | X     |       |       |
| Bird     |       | X     | X     |
| Duck     | X     | X     | X     |

Notice how for each combination of swimming, walking and flying, there is a living creature that can do just that, with the exception of swimming and flying.

Sure there are flying fish, but they glide rather than fly. Did evolution really forget to cover this niche?

  • MrsDoyle@sh.itjust.worksEnglish
    1·
    2 days ago

    Yes, that’s true. But it’s more a stumbling waddle than a walk. I looked at some videos of gannet colonies, and hardly any of the tens of thousands of birds are walking. I think like most of these diving seabirds their feet are set well back.

    This is a really nice vid of a Canadian colony: https://youtu.be/g9bzWqfIu2Y

    • ulterno@programming.devEnglish
      0·
      1 day ago

      Considering that I am including a snake’s movements in “walking” in this context, I’d say that’s good enough.
      Honestly though, considering 2/3 of the planet surface (and increasing) is water, one would think there would be some answer to this, but I suppose it has something to do with the physics of it…

      • There is a lot of vertical space in the oceans and it is possible for some, to escape to depths that other species cannot.
      • As compared to that, fast vertical movement in a land area will mostly include air-time, meaning gliding will give an advantage by reducing fall damage.
      • There is a sharp drop in the buoyancy from water to air, meaning that anyone wanting to move to air to escape underwater threats will require much lower body densities, which in turn make it harder to have long deep-water time and there are more resources underwater anyway

      So I think that the air-time of flying-fish is optimised more than enough for such a purpose and that the birds that we see diving to get food are more from the evolutionary route of - land animals that can fly, adapting to get food from deeper into the water.

      • MrsDoyle@sh.itjust.worksEnglish
        1·
        19 hours ago

        I’m finding this discussion so interesting! It’s honestly something I’d never thought of at all, but it’s an excellent exercise for my brain. Gannets have evolved special protection for their brains when diving, btw. They hit the water at 60mph. I wish we’d evolved some cooler attributes than opposable thumbs and walking upright. Gills, for example. Ah well.