The chances that the life on another planet could possibly affect us, unless we are talking about animals, is VERY low. Bacteria, protozoans, and viruses on earth have, essentially, targeted us and evolved to be more efficient killers. The chances that alien microorganisms could have developed characteristics that would be harmful to us is pretty low.
According to theories of what the earth's atmosphere was like before life flourished, the atmosphere was full of CO2 and nitrogen. There was no oxygen. According to our understanding of the earth 4 billion yrs ago, the earth would be a VERY different place today if there were no life here because oxygen is a byproduct of photosynthetic life.
I theorize that the moment we find a planet like ours, we will have found life on another planet.
Slashdot Mirror
The chances that the life on another planet could possibly affect us, unless we are talking about animals, is VERY low. Bacteria, protozoans, and viruses on earth have, essentially, targeted us and evolved to be more efficient killers. The chances that alien microorganisms could have developed characteristics that would be harmful to us is pretty low.
According to theories of what the earth's atmosphere was like before life flourished, the atmosphere was full of CO2 and nitrogen. There was no oxygen. According to our understanding of the earth 4 billion yrs ago, the earth would be a VERY different place today if there were no life here because oxygen is a byproduct of photosynthetic life. I theorize that the moment we find a planet like ours, we will have found life on another planet.