Astronomy Cast 2.1: Exotic Life (Episode 209)

Recently, in Mono Lake in California, a single-celled bacteria was found that has the ability to replace phosphorous DNA with arsenic.  This is such a big deal because they can essentially change the entire structure of their DNA, and become a completely different organism from those found on Earth.  What is also interesting is that they live in a lake with high levels of arsenic, which would be deadly for most organisms.  Because of this extreme condition, they evolved to fit their surroundings.  Because of this discovery, scientists are trying to get funding to search for alien life in places other than those that have water because we now know that organisms exist that are different from humans structurally.