3 ms·

Experience on earth that they eventually evolve hands.

cutemonster 2y ago
That's because there's land here, but what about a planet with only water, or just not enough land. But maybe water-surface-only (no land surface) is unlikely
- manmal 2y ago
  There would still be enough earth like planets with land.
- oersted 2y ago
  Why would water prevent the evolution of hands? Lots of sea creatures have claws. The sea is also not all that different from an atmosphere with a higher density in principle, we live "under-air".
  - cutemonster 2y ago
    Looking at this planet, it's less likely to happen. Maybe high density (water) makes tools less useful, and thus hands less useful, since you cannot move a tool particularly fast under water, compared to on land. I suppose you've tried throwing a stone underwater -- compare with throwing on land. From this seems to follow, that creatures with human like intelligence, are less likely to appear, if the density of the liquid or gas surrounding them, is too high. (Dolphins are bright but not that bright.)
RedNifre 2y ago
That is incorrect, dolphins are unlikely to evolve hands and humanoids evolved hands before they became intelligent (probably to grab branches). It was very lucky that a good brain evolved in a body that already had hands.
- cutemonster 2y ago
  > very lucky that a good brain evolved in a body that already had hands. The other way around: hands adds evolutionary pressure towards becoming more intelligent. (The ones that understand how to use their hands and tools better...)
- DoctorOetker 2y ago
  The lack of knowledge. Dolphins do have organs with which they pick up things like rocks or shells and they are able to give them to each other. They use their sexual organs as "hands"! Both males and females. In the tree of life brains are correlated much more strongly with locomotion than with hands. The moment you need to do (inverse) kinematics to plan an immediate action, and to plan sequences of motions, and to plan a hunting or fleeing strategy, is what put pressure to evolve brains, static lifeforms can be very complex and have complicated genomes, but brains you wont find in them...
Shorel 2y ago
If elephants were carnivores, with their trunks, they would have evolved efficient methods to hunt, and would probably be the dominant species on the earth landmass surface. All this without hands. The fact that they are vegetarian gave us the chance to do that evolution ourselves.

That's because there's land here, but what about a planet with only water, or just not enough land. But maybe water-surface-only (no land surface) is unlikely

manmal 2y ago
There would still be enough earth like planets with land.
oersted 2y ago
Why would water prevent the evolution of hands? Lots of sea creatures have claws. The sea is also not all that different from an atmosphere with a higher density in principle, we live "under-air".
- cutemonster 2y ago
  Looking at this planet, it's less likely to happen. Maybe high density (water) makes tools less useful, and thus hands less useful, since you cannot move a tool particularly fast under water, compared to on land. I suppose you've tried throwing a stone underwater -- compare with throwing on land. From this seems to follow, that creatures with human like intelligence, are less likely to appear, if the density of the liquid or gas surrounding them, is too high. (Dolphins are bright but not that bright.)

RedNifre 2y ago

That is incorrect, dolphins are unlikely to evolve hands and humanoids evolved hands before they became intelligent (probably to grab branches). It was very lucky that a good brain evolved in a body that already had hands.

cutemonster 2y ago
> very lucky that a good brain evolved in a body that already had hands. The other way around: hands adds evolutionary pressure towards becoming more intelligent. (The ones that understand how to use their hands and tools better...)
DoctorOetker 2y ago
The lack of knowledge. Dolphins do have organs with which they pick up things like rocks or shells and they are able to give them to each other. They use their sexual organs as "hands"! Both males and females. In the tree of life brains are correlated much more strongly with locomotion than with hands. The moment you need to do (inverse) kinematics to plan an immediate action, and to plan sequences of motions, and to plan a hunting or fleeing strategy, is what put pressure to evolve brains, static lifeforms can be very complex and have complicated genomes, but brains you wont find in them...

Shorel 2y ago

If elephants were carnivores, with their trunks, they would have evolved efficient methods to hunt, and would probably be the dominant species on the earth landmass surface. All this without hands. The fact that they are vegetarian gave us the chance to do that evolution ourselves.