Thanks! :-)

This image from the book is misleading:

It suggests that the North Indian, Tibetan and Korean scripts are in a line of descent from modern Arabic. There is a hypothesis that Korean Hangul script was based in part on the Mongol 'Phags-pa script, which was in turn based on Tibetan, but the hypothesis is not widely accepted. More problematic, though, is the line through Arabic. To my knowledge there is no theory or evidence linking the Northern Indian scripts with Arabic: they're not even in the same class of writing systems. Perhaps the authors were confusing two the different Mongolian scripts -- 'Phags-pa and Uyghur -- and their lines of descent, and extrapolating an incorrect line from Arabic to Korean. It should be something like

Aramaic ~> Brahmic -> North Indian -> Tibetan -> 'Phags-pa ~> Korean

and

Aramaic -> Syriac -> Sogdian -> Uyghur -> Mongolian

Thanks John

I will alert the author(s) to what you say here.

Hello John,

Shame on us. Of course you are right with your correction. I just mailed Geert and he looked again in his sources (the dutch translation of The Joy of Knowledge, Editor James Mitchell, Published by Beazley Encyclopedias Ltd 1976, London and www.ancientscripts.com).
There is indeed a design flaw in the diagram. The link between Nothern Indian and Modern Arabic is false. The line from Northern Indian had to go to Brahmin.
Of course the diagram can be enhanced with the suggestions you do and we will consider that of course in a reprint. At the time Geert was making the diagram the chart in the enclosed picture (in dutch) was his main source. With your correction and the info on www.ancientscripts.com we can make it better the next time. Thanks for your input!