I don't get the arguments for bioessentialism

[Maxperson]

This example doesn't work for me; isn't the point of Frodo taking the ring require that he his less fit for adventuring and ruling than Aragorn?

One of the reasons, and perhaps the most important reason, is that hobbits are racially resistant to magical corruption.

 

[Maxperson]

Perhaps. I am merely positing that you have to go to some pretty great lengths to make that undeniably biological, as opposed to cultural.

Yep. 1000 meters. Kuo-toans lived on the surface, but retreated to the depths of the ocean and the underdark. They adapted to their lightless environments. Light penetrates the ocean to a depth of about 1000 meters, so we are talking about a humanoid race capable of living on the surface and an ocean depth of at least 1000 meters. Without gear.

That doesn't sound cultural to me. Sounds like they have a pretty strong and hardy body to withstand those pressure differences.