If its Adam then the remains should be around 6700 years old (or was it 8700?). Seems your idea is out by a mere 390 000 years. Lets stick to actual facts in Natural Sciences
Carbon dating is one of the least exact sciences out there. So is counting ice-rings at the poles etc.
Just about 15 years ago, a number of planes from WWII was discovered by sonar in Iceland/Greenland/somewhere.
According to the existing ice-ring dating, the planes was supposedly buried beneath the snow for a couple of hundreds of years.
Carbon doesn't only deteriorate with TIME, there are gazillions of other factors: Temperature when the animal/person died, pH of the surrounding ground, vegetation, exposure to sun, wind etc, amount of pressure applied, etc etc.
If you search through WikiLeaks you'll find an article on carbon dating where a skeleton was thought to be around 10 000 years old, yet it was a skeleton that had been buried under Pine trees for around 40 years.
Science is awesome when it's theory can be PROVED (meaning FACT).
Science and religion is exactly the same thing when theory upon theory upon theory suddenly becomes widely acceptable.
One nice example depicting theoretical science is that ad on Discovery channel:
If you ARE, you BREATHE, if you BREATHE you bleh bleh, ..... , and suddenly, you are ALIVE!
