This topic is really interesting to me. It's something my younger brother and I have pondered over together for years. He's the one who got me to read Ray Kruzweil's book, "The Singularity is Near," and we were collectively frustrated at what we saw as the main character's stupidity in "Tuck Everlasting" when she decided not to drink the immortality water ("Tuck deserves a girl smart enough to drink the water," my brother said, and I agree).
Anyway, my brother was so interested in longevity research, he went on to get his Ph.D. in Molecular Biology with a specialization in longevity studies last year. He is now working on starting his own biotech company. I couldn't be more proud (proud big sister, here).
I asked him about the maximum human lifespan last week, when I read an article that said some researchers believe it is no more than 115 (despite documented evidence of people living a bit longer). He said he thinks in a natural, perfect world with no diseases or accidents, the maximum human lifespan is probably about 140.
But, he also says that can be greatly increased with a combination of drugs and DNA editing, which he believes we will see become readily available in society in the next few decades. So, that is something is he contributing to making happen. And, it's something we're both looking forward to, when it gets here, as it will change the human race for the better, and make a better world, and life, for all of us.
Thanks for the comment. I am also very interested in this topic and I also ended up working with this in a start-up doing genomics software. This whole topic is both fascinating and scary, because it has the potential of deeply changing human race and could change it for the worst if not done carefully (have you ever watched Gattaca?). Anyway, send my best to your brother!