> 3. I was told that the more introns that you have, the greater your
> lifespan. But if all genes are at fixed loci, how can one human have
> more introns than another? It seems to me that loci positions would
> restrict intron length.
Your other questions were answered.
I think you're confusing introns with telomeres here. There's not really a
direct connection between telomere length and lifespan, but it works like
Telomeres are repetetive sequences at the end of chromosomes. When a
chromosome is replicated, the ends get lost, so the telomeres act as a sort
of buffer of losable material.
When you run out of telomeres, your DNA will start missing vital stuff,
eventually, and then you'll die from a lack of one or more vital proteins.
This is a problem with animal clones. The cloned DNA has whatever telomere
length the parent had, whereas an ovum fertilized from a sperm gets its own
brand new set of telomeres.
I don't think this is a normal cause of death in people. I think organs
usually give out, or disease develops, before your run out of telomeres, but
I could be wrong.