Um, do you know anything about math, biology, or genetics? Anything at all? Well, anything beyond 12th grade?<quoted text>If the average was 35 years there would still be lots of people involved.
If you factor in the optimal lifespan for every era and start with 8 people, we'd be extinct by about 100 years after such a bottleneck. Human genetic diversity was ever that great, if we were reduced to 8 people, even with today's technology, we'd go extinct, especially if all 8 people were directly related.