You can probably propose a new SI-base unit of “a mother”, but what does it measure?

“Metric” just essentially comes from “metering”. People confuse “metric” with “decimal”, which is sort of the point of the person I replied to. While metric time technically exists insofar as you just use seconds as the base unit, omit minutes and hours and just do SI-prefixes, the French did also try decimal time, but it was just horrible.

So if “mother” was the base unit and it measured something, in this instance time, the advent of agriculture was roughly four hectomothers ago. Or 0.4 kilomothers, if you will.