Why The Pig Is The Symbol Of Non Kosher Animals?

Shamrya Rosenberg has published an interesting if unconvincing account of Christopher Hitchens explanation why a pig is not kosher. To sum it up - he believes the similarity between pigs and humans made pigs a semi cannibalistic symbol.

I'm not going to argue, mostly because I honestly believe that the question of why a pig is not kosher is a dead end question. All answers will be little more than theories, and rely on some shaky assumptions.

However, what is an interesting question for me, is why did the pig become THE symbol for non kosher food?

A look at the Torah, shows that there is nothing unusual in the Psukim that forbid eating pigs:

אֶת-הַשָּׁפָן, כִּי-מַעֲלֵה גֵרָה הוּא, וּפַרְסָה, לֹא יַפְרִיס; טָמֵא הוּא, לָכֶם.	5 And the rock-badger, because he cheweth the cud but parteth not the hoof, he is unclean unto you.
ו  וְאֶת-הָאַרְנֶבֶת, כִּי-מַעֲלַת גֵּרָה הִוא, וּפַרְסָה, לֹא הִפְרִיסָה; טְמֵאָה הִוא, לָכֶם.	6 And the hare, because she cheweth the cud but parteth not the hoof, she is unclean unto you.
ז  וְאֶת-הַחֲזִיר כִּי-מַפְרִיס פַּרְסָה הוּא, וְשֹׁסַע שֶׁסַע פַּרְסָה, וְהוּא, גֵּרָה לֹא-יִגָּר; טָמֵא הוּא, לָכֶם.	7 And the swine, because he parteth the hoof, and is cloven-footed, but cheweth not the cud, he is unclean unto you. (Leviticus 11)

As can be seen the phrasing "unclan unto you" appears in both for the "Rock-badger" and "Hare" (sorry Rabbi Slifkin). A similar Pasuk appears in Deutronomy 14:7 - but it also does not have any unusual language.

The antiquity of the Pig=Unkosher symbol is evident in the Bible. In Isaiah (64:17) we find for example:

יז  הַמִּתְקַדְּשִׁים וְהַמִּטַּהֲרִים אֶל-הַגַּנּוֹת, אַחַר אחד (אַחַת) בַּתָּוֶךְ, אֹכְלֵי בְּשַׂר הַחֲזִיר, וְהַשֶּׁקֶץ וְהָעַכְבָּר--יַחְדָּו יָסֻפוּ, נְאֻם-יְהוָה.

17 They that sanctify themselves and purify themselves to go unto the gardens, behind one in the midst, eating swine's flesh, and the detestable thing, and the mouse, shall be consumed together, saith the LORD

This pasuk is interesting because it mentions in one breath the pig, mouse and detestable food. In other words - the pig is a symbol, but so is the mouse.

In the Talmud, there is no shortage of Midrashim that show that the Pig was clearly an established symbol. So I'm guessing that somewhere between the biblical times and the Talmud, the pig was elevated to being the ultimate symbol of non kosher food. Some have speculated, that it is because the roman legion which burned down the temple (Legion X Fretensis) had a boar as one of its symbols - and hence the pig became the symbol for the destruction of the temple. (I somewhat doubt this explanation, but it does make me wonder about the Aggadah that the Romans sent a pig as a sacrifice, and when his hooves touched the walls of the Temple, Jerusalem shook).

I'm happy to hear any suggestions.