Age-enhancing science is a finite field. One day, we will fully understand the cell cycle and DNA damage and telomeres and we will literally become immortal (that is IF WE ALL STOP USING ANTIBACTERIAL SOAP). Alterations to DNA repair mechanisms will bring the average age of a human to dizzying heights, and with that come serious issues.
The same evolution that produced humans intelligent enough to recognize their place in the Earth's progression will lead to, well.. the death of evolution. Instead of the rise and fall of generations, a small fraction of humans will defiantly exit this cycle. There will be a tiny subset of people whose DNA will achieve the pure, white bliss of genetic immortality.
But who will this benefit? Those who can afford it, at first. Eventually, procedures to optimize which genes are expressed when and where will be available in strip-mall medical clinics in suburbia. The 'first person to never die' will be born. The rest of the world will keep dying. The rift between the affluent and the rest will grow, endlessly.
99.9% of all species that have ever lived on our little rock hurtling through space are gone, which aren't great odds. I doubt we'll ever make it to immortality. HIV could mutate to be transmissible as an aerosol, or an asteroid the size of the moon could smash into the Earth at 35 kilometres/second. Which is probably for the best.
TLDR: Did you know? When you release a helium balloon into space, you're gifting space that bit of helium for good. We actually MINE most of our helium from the ground, and it's running out.