Mamzer Question on Kiddushin 72b

Question

The gemarah in Yevamos (78b) says "mamzer eino chai" (A mamzer [who is not known, look later in the daf] doesn't live [for more that 12 months] so not to proliferate mamzeirim).

However, the Gemarah in Kiddushin (72b) say that if not for the din "Keivan shenitmaa nitmaa" (a unknown mamzer is considered Kosher) when Eliyahu would come, he would take out bunches and bunches of mamzeirim who were lost within the Jewish people.

My question is how could there be so many of them if they should have died as soon as we lost track of them?

Answer 1

Only a mamzer who is halachically classified as a mamzer "dosn't live" (2 witnesses). Mamzers who are questionably mamzers survive.* Rab Yehudah says in the future those uncertain-mamzers will be kosher Jews that Eliyahu won't have to sort through. (Where as if R. Yehudah had not posseked that way, then Eliyahu would have had to remove the bunches and bunches of them in the time of meshiach.)

* http://dafnotes.blogspot.com/2007/07/mamzer-will-not-survive-yevamos-78-daf.html