Photographer's quest to find oldest living things

(Llareta shrub from the Atacama Desert in Chile (hint: it's not a moss). Source: rachelsussman.com)

New York-based photographer Rachel Sussman is traveling around the world to photograph the world's oldest living things (photo gallery).

She also has an OLTW blog and is soliciting donations to fund her work.

The pictures are great, but makes one wonder about the arbitrariness of her criteria - there must be tons of stuff out there she's missing! Other thoughts: what makes a biological individual (should colonial organisms count?), what do old things have in common (do they all grow slowly?), and what selective forces favor longevity?

(via the Guardian)