3 ms·

For so many species to have indepently developed wood, it must be a highly beneficial (or, at least, not detrimental) adaptation that is relatively easy for pla

For so many species to have indepently developed wood, it must be a highly beneficial (or, at least, not detrimental) adaptation that is relatively easy for plants to mutate. I would not expect a more complicated fundamental structure (an eye, for example) to have developed indepedently numerous times, but something a bit simpler like wood is not terribly surprising. I am expecting responses to the tune of "eyes are not that complicated" and "wood is actually incredibly complex." Do all creatures with a brain share a common ancestor? Even more fundamentally, do all creatures share a common ancestor? The answer appears to be "maybe," which I find to be fascinating [1]. 1.https://www.researchgate.net/publication/44593277_A_formal_test_of_the_theory_of_universal_common_ancestry https://www.researchgate.net/publication/44593277_A_formal_t...

Scene_Cast2 6y ago
The eye has been developed twice - check out cephalopod eyes. If anything, their design is superior (no blind spot, nerves on the rear vs front, hard lens vs soft deformable lens for focusing)
- DangitBobby 6y ago
  That's interesting. The Wikipedia entry [1] mentions that there's still debate about whether it's parallel evolution [2] or convergent evolution [3]. I'm very curious about why this comment got downvoted. 1.https://en.m.wikipedia.org/wiki/Cephalopod_eye https://en.m.wikipedia.org/wiki/Cephalopod_eye 2.https://en.m.wikipedia.org/wiki/Parallel_evolution https://en.m.wikipedia.org/wiki/Parallel_evolution > Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure. 3. https://en.m.wikipedia.org/wiki/Convergent_evolution https://en.m.wikipedia.org/wiki/Convergent_evolution > Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time.
  - CRConrad 6y ago
    Those categories feel a bit arbitrary and overlapping: The difference between 2 and 3 seems to be whether there is a shared "similar original trait"... So, wouldn't every process of convergent evolution, where a similar trait arises independently in different species -- after a while automatically and inevitably have become parallel evolution, because after some time the once-new trait has of course become a pre-existing one? OK, OK, I'll go check on that debate... But given the quotes of the definitions you posted here, it sure seems pseudo-.
- bewo001 6y ago
  There are also compound eyes. The mantis shrimp's eyes cover a far larger part of the spectrum at better spectral resolution than our crummy vertebrate eyes. The can distinguish polarization and have some degree of depth perception within a single eye.

Scene_Cast2 6y ago

The eye has been developed twice - check out cephalopod eyes. If anything, their design is superior (no blind spot, nerves on the rear vs front, hard lens vs soft deformable lens for focusing)

DangitBobby 6y ago
That's interesting. The Wikipedia entry [1] mentions that there's still debate about whether it's parallel evolution [2] or convergent evolution [3]. I'm very curious about why this comment got downvoted. 1.https://en.m.wikipedia.org/wiki/Cephalopod_eye https://en.m.wikipedia.org/wiki/Cephalopod_eye 2.https://en.m.wikipedia.org/wiki/Parallel_evolution https://en.m.wikipedia.org/wiki/Parallel_evolution > Parallel evolution is the similar development of a trait in distinct species that are not closely related, but share a similar original trait in response to similar evolutionary pressure. 3. https://en.m.wikipedia.org/wiki/Convergent_evolution https://en.m.wikipedia.org/wiki/Convergent_evolution > Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time.
- CRConrad 6y ago
  Those categories feel a bit arbitrary and overlapping: The difference between 2 and 3 seems to be whether there is a shared "similar original trait"... So, wouldn't every process of convergent evolution, where a similar trait arises independently in different species -- after a while automatically and inevitably have become parallel evolution, because after some time the once-new trait has of course become a pre-existing one? OK, OK, I'll go check on that debate... But given the quotes of the definitions you posted here, it sure seems pseudo-.
bewo001 6y ago
There are also compound eyes. The mantis shrimp's eyes cover a far larger part of the spectrum at better spectral resolution than our crummy vertebrate eyes. The can distinguish polarization and have some degree of depth perception within a single eye.