Mike Lyle schreef
What advantage do walnuts and their relatives gain from having the
kernels of their nuts such an unusual shape? From my non-walnut point
of view it seems that having so many sticking-out bits increases the
risk of mechanical damage and drying-out.

Mike.

+ + +
Once upon a time this would have been an easy question.
It was to resemble to a brain, so as to show walnuts were "brain food".
PvR