PITTSBURGH -- A Pittsburgh archeologist has unearthed what he believes is the oldest known example of the modern alphabet. The discovery was made in Tel Zayit, Israel, which lies not far from the coast and very close to the Gaza Strip.

That's where Dr. Ron Tappy, a professor from the Pittsburgh Theological Seminary, and his team began what's known as the Zeitah excavations.

"It's an interesting story how this unfolded. There's a kind of Murphy's Law in archeology that your best discoveries come out at the end of the season every year. I don't know that happens, but it's in the last few days that you find your best stuff," said Tappy.

The excavations began back in 1999.

On July 15, 2005, the final day of the 2005 season in the field, excavators found embedded in a wall a 38-pound limestone boulder with obvious inscriptions of Hebrew letters.

"We did not realize right away what the inscription was -- that it was, in fact, an A-B-C-D-E-R-Y, and not a text with nouns and verbs. We didn't realize that right away. We could just see a few of the letters," said Tappy.

The Tel Zayit inscription represents an extremely important landmark in the history of alphabetic writing.

Tappy says it's the most concrete evidence that Israelites were literate as early as the 10th century B.C.

"We see now that they had in this region of the country -- a fully developed alphabet which means that they could have written anything," said Tappy.

Tappy believes our modern alphabet descended directly from the letters seen on the Tel Zayit inscription.