Genes, lifestyle, and longevity

So I spent the weekend with my lovely wife and her family celebrating...

her Nanna's 90th birthday. She had another uncle present who is 94 years old and seems more spry and active than some thirty somethings I know.

This led me to reflect a little bit on the fact that nobody in my family lives into their nineties, and damn few live into their eighties (Or have thus far).

There are a number of factors that could readily explain this without too much digging. My family has traditionally been lower middle class, blue collar workers. As I've mentioned here before, my mom and dad meet during WWII while working as mechanics repairing amphibious vehicles (My dad was her foreman :). My uncles and cousins mostly worked in plastic factories and the like, and all but the most recent generation smoked all their (comparatively short) lives.

If longevity could be thought of as a graph with lifestyle, age and genetics all expressed as axes, I wonder what our two families would look like? Add in recent developments in the understanding of how epigenetics effects longevity and by extension how the environment and lifestyle of an organism can effects its offspring one, two or even three or more generations down the line, and you wind up with a dizzying multi-dimensional data structure whose representation I can't even fathom.

Kinda leaves me feeling grateful that we're not planning on having children any time soon :)

This rant (meander? pile of babble? I dunno) has no conclusion per se. Just a bunch of thoughts that have been rolling around in my head for a bit.