mankind:

Biological material decays too fast

Measurements of the mutation rate of mitochondrial DNA recently forced researchers to revise the age of “mitochondrial Eve” from a theorized 200,000 years down to possibly as low as 6,000 years. DNA experts insist that DNA cannot exist in natural environments longer than 10,000 years, yet intact strands of DNA appear to have been recovered from fossils allegedly much older.

“For example, researchers have calculated that "mitochondrial Eve" the woman whose mtDNA was ancestral to that in all living people lived 100,000 to 200,000 years ago in Africa. Using the new clock, she would be a mere 6000 years old.”
(Gibbons, Ann, “Calibrating the Mitochondrial Clock”, Science, Vol 279, No. 5347, Jan 1998, pp. 28 & 29)
[link to www.icr.org]
[link to creation.com]


Claim:
The Sumer tablets are the oldest text.

Reply:
Understand how textual dating is done: the physical dating of the text does not date the original text, which is dated by events and confirmed with the sciences.

"The oldest known tablets written in stone," means little, as original biblical texts were copied to parchment repeatedly and the originals destroyed as they were used to the point of being worn out and useless. But by this time there were thousands of copies so originals were unimportant. Older scripture has no validity over the majority text in agreement: Majority coming from different parts of the world, all in agreement. This is what is found with the Textus Receptus Greek New Testament and Hebrew Masoretic Old Testament, King James Version manuscripts. Oldest known does not mean more credible or reliable in textual criticism, just means the originals were destroyed, lost or possibly being kept from us.

But that's not all, in the text are events and figures. The pagan Sumer tablets do not tell of real events, while the books of the Bible are confirmed repeatedly with HISTORY and SCIENCE.