aliens in our midst

[the_grynne]

"The search for alien life need not involve expensive interplanetary missions. If life does form readily then we might expect it to have arisen many times on our home planet. Ward discusses the intriguing idea that alien organisms may lurk all around us, unrecognised for what they are because they fail to respond to standard biochemical analysis. For example, there could be microbes that use RNA instead of DNA, or employ a different genetic code. Such organisms might very well be passed over by microbiologists focused on life as we know it. Ward also makes a case that some viruses could be relics of ancient alternative forms of life."

In search of a second genesis (excerpt), Paul Davies, New Scientist, 11 February 2006
Review of: Life As We Do Not Know It: The NASA search for (and synthesis of) alien life, by Peter Ward, Viking [Amazon]