5000 Years of Technology

After digging to a depth of 100m last year, Russian scientists found traces of copper wiring dating back 1000 years, and came to the conclusion that their ancestors already had a telephone network one thousand years ago.
So as not to be outdone, in the weeks that followed, American scientists dug 200m, and headlines in the US newspapers read:
"US scientists have found traces of 2000 year old optical fibres, and have concluded that their ancestors already had advanced high-tech digital telephones 1000 years earlier than the Russians."
One week later, the Nigerian press reported the following:
"After digging as deep as 500m, Nigerian scientists have found absolutely nothing. The government have concluded that 5000 years ago,their ancestors were already using mobile phones due to cable theft problems.