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https://en.wikipedia.org/wiki/Pfeilstorch https://en.wikipedia.org/wiki/Pfeilstorch But that's different, I doubt birds intentionally carry anything from Afric

https://en.wikipedia.org/wiki/Pfeilstorch https://en.wikipedia.org/wiki/Pfeilstorch But that's different, I doubt birds intentionally carry anything from Africa either.

hutzlibu 5y ago
"Before migration was understood, people struggled to explain the sudden annual disappearance of birds like the white stork and barn swallow. Besides migration, some theories of the time held that they turned into other kinds of birds, mice, or hibernated underwater during the winter, and such theories were even propagated by zoologists of the time." Ok, it seems that Aristoteles believed, that birds actually transformed, but zoologist of that time at most believed, that they hibernated underwater", which seems a more solid theory, than transforming.
- thaumasiotes 5y ago
  Transforming isn't exactly unknown; all insects do it.
  - hutzlibu 5y ago
    Yes, but by the 18.th century, we knew that birds and mammals are a bit more complex than insects and quite shape stable.
    - thaumasiotes 5y ago
      Shape stability would be an example of being less complex than insects. And as you can see, we did not in fact know that in the 18th century. Transformations are not so easy to observe directly; they often happen e.g. underground.
      - hutzlibu 5y ago
        "Shape stability would be an example of being less complex than insects." Not if the shape is stable, because the underlying cells are too complex to merge into something different. Cells were known already. And that insects transform is known, but birds were closely known and there was not observation of them changing drastically. So that Aristoteles had this thinking is understandable given the time, but after enlightenment, I would not expect that from the early scientists.
        thaumasiotes 5y ago
        > Not if the shape is stable, because the underlying cells are too complex to merge into something different. This is not a valid concept. Vertebrates develop from stem cells the same way insects do.
- deleted 5y ago
  [deleted]
- sdiupIGPWEfh 5y ago
  > Besides migration, some theories of the time held that they turned into other kinds of birds... Makes me think of loons, which completely change their plumage for the winter in addition to migrating from fresh water lakes to oceanic waters. Without close study, you might not realize they're the same birds.

https://en.wikipedia.org/wiki/Pfeilstorch https://en.wikipedia.org/wiki/Pfeilstorch But that's different, I doubt birds intentionally carry anything from Africa either.

hutzlibu 5y ago

"Before migration was understood, people struggled to explain the sudden annual disappearance of birds like the white stork and barn swallow. Besides migration, some theories of the time held that they turned into other kinds of birds, mice, or hibernated underwater during the winter, and such theories were even propagated by zoologists of the time." Ok, it seems that Aristoteles believed, that birds actually transformed, but zoologist of that time at most believed, that they hibernated underwater", which seems a more solid theory, than transforming.

thaumasiotes 5y ago
Transforming isn't exactly unknown; all insects do it.
- hutzlibu 5y ago
  Yes, but by the 18.th century, we knew that birds and mammals are a bit more complex than insects and quite shape stable.
  - thaumasiotes 5y ago
    Shape stability would be an example of being less complex than insects. And as you can see, we did not in fact know that in the 18th century. Transformations are not so easy to observe directly; they often happen e.g. underground.
    - hutzlibu 5y ago
      "Shape stability would be an example of being less complex than insects." Not if the shape is stable, because the underlying cells are too complex to merge into something different. Cells were known already. And that insects transform is known, but birds were closely known and there was not observation of them changing drastically. So that Aristoteles had this thinking is understandable given the time, but after enlightenment, I would not expect that from the early scientists.
      - thaumasiotes 5y ago
        > Not if the shape is stable, because the underlying cells are too complex to merge into something different. This is not a valid concept. Vertebrates develop from stem cells the same way insects do.
deleted 5y ago
[deleted]
sdiupIGPWEfh 5y ago
> Besides migration, some theories of the time held that they turned into other kinds of birds... Makes me think of loons, which completely change their plumage for the winter in addition to migrating from fresh water lakes to oceanic waters. Without close study, you might not realize they're the same birds.