A very exciting development in the world of biology. Apparently, bacteria has been generated that uses arsenic in place of phosphorous as one of its basic building blocks. This is a big deal!
You see, up until now, the only life we’ve ever observed uses the following basic elements:
(H)ydrogen, (O)xygen, (N)itrogen, (C)arbon, (S)ulfur, and (P)hosphorus.
But if you look at the periodic table, the element directly below Phosphorus is Arsenic. This means that Arsenic’s outer shell of electrons has the same bonding structure as its upstairs cousin. This in turn means that at least as far as bonding is concerned, it might be possible to take chemicals that involve Phosphorus and to swap it out for Arsenic.
This is what happens to these bacteria: they are put into a Phosphorus starved/Arsenic rich environment. They somehow develop the adaptation to use Arsenic instead of Phosphorus for basic chemical structures such as DNA!
There have been a lot of stories about this in the news. This one from Wired is at least as good as the others.