These signed evolved with time. By the Middle Ages the asterisk and the dagger could be used to indicate a pause when reciting Psalms. (Those of us at Nashotah House in the 1990s know all about pauses when reciting Psalms.) Medieval scribes marked up manuscripts religiously. Eventually the asterisk came to be associated with footnotes—a function that it still has, mostly in non-academic texts. The dagger was used for a footnote if an asterisk had already been used on that page. Beyond that, the double-dagger came into play. The function and the form of the obelus had now evolved solidly into the dagger form. The obelus continued on in math, at one time to mean subtraction, but finally settling down to represent division. Appropriate, given its graphic origins.
The dagger and asterisk were the earliest signs of textual criticism. Literalists today still don’t understand the concept, since all ancient documents of the Bible are copies of copies of copies. Nevertheless, how did a sign indicating a spit upon which an animal was roasted come to represent the dearly departed? Since asterisk and dagger often work as a pair, the most obvious way that this worked out was in representing the birth and death years of a person. An asterisk before the name meant “born in,” while a dagger in the same position meant “died in.” As a kind of typographical shorthand, then, a dagger after a name meant the person had died. Although it sounds dramatic and not a little violent, it is really only death by textual criticism. That, I suspect, is something most biblical scholars especially will be able to comprehend.