Most people live within 50 km of their parents, and the range of spiritual (radio waves) communication could be a reflection of that. Microtubules vibrate in kilohertz, wavelengths measured in kilometer, and because of their long wavelength, their radio waves can diffract over obstacles like mountain ranges and travel beyond the horizon, following the contour of the Earth. Tubulin dimers vibrate in the megahertz, and local sites on tubulin in the gigahertz.
Synapses
Distance to elderly parents: Analyses of Swedish register data (2007)
The Typical American Lives Only 18 Miles From Mom (2015)