The differences between Elves and Men

[mhagain]

Tolkien's final words on the matter seem to have been expressed in his author's commentary to the Athrabeth Fonrod ah Andreth (HoME 10):

There are certain things in this world that have to be accepted as 'facts'. The existence of Elves: that is of a race of beings closely akin to Men, so closely indeed that they must be regarded as physically (or biologically) simply branches of the same race.

So there we have it: physically and biologically Elves and Men are the same species (Eruhini), and any differences between them (on the purely physical or biological level) are merely nothing more than common intra-species variation.

Some of the common tropes about Elves are not even suggested, or even outright denied, by Tolkien's work. That they're can't get drunk is false: Galion did. That they're immune to poison is false: Aredhel died of poisoning.

Of course outside of the physical and biological aspects there are other differences.