Would there be life?

Amino acids are small, highly reactive molecules composed of 20 to 30 HCNO atoms. When amino acids link together in strings they form proteins. Proteins govern chemical reaction rates and form the structural material for cell parts.

 

Most importantly, they can form into microspheres when heated, which serves to separate chemical reactions and processes. The problem is that with the vastness of the Earth's oceans it is statistically very improbable that these early proteins would ever link up. The solution is that the huge tides from the Moon produced inland tidal pools, which would fill and evaporate on a regular basis to produce high concentrations of amino acids, who then linked themselves into macromolecules.

As we can see from this lecture life may have evolved specifically in the tidal pools caused by having a large moon. There are other theories that state this could have happened near thermal vents, so you could have life, we don't know.

There's a secondary question here:

Would life have moved on to land without intertidal zones?

Possibly not - need sources.

Is a lifeless planet habitable?

That depends on how you're defining habitable, but in short: Not to us. A planet without plant life similar to ours is unlikely to have the right balance of oxygen/nitrogen/etc in the atmosphere for us to be able to just turn up and breathe. You're going to have to wait a few thousand (maybe million) years after seeding it with photosynthesising plants to give an atmosphere mammals could survive in.

Would there be life?

Amino acids are small, highly reactive molecules composed of 20 to 30 HCNO atoms. When amino acids link together in strings they form proteins. Proteins govern chemical reaction rates and form the structural material for cell parts.

Most importantly, they can form into microspheres when heated, which serves to separate chemical reactions and processes. The problem is that with the vastness of the Earth's oceans it is statistically very improbable that these early proteins would ever link up. The solution is that the huge tides from the Moon produced inland tidal pools, which would fill and evaporate on a regular basis to produce high concentrations of amino acids, who then linked themselves into macromolecules.

As we can see from this lecture life may have evolved specifically in the tidal pools caused by having a large moon. There are other theories that state this could have happened near thermal vents, so you could have life, we don't know.

There's a secondary question here:

Would life have moved on to land without intertidal zones?

Possibly not - need sources.

Is a lifeless planet habitable?

That depends on how you're defining habitable, but in short: Not to us. A planet without plant life similar to ours is unlikely to have the right balance of oxygen/nitrogen/etc in the atmosphere for us to be able to just turn up and breathe. You're going to have to wait a few thousand (maybe million) years after seeding it with photosynthesising plants to give an atmosphere mammals could survive in.