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STScI Astrobiology Lecture Series

Searching for, or Creating Ourselves, a Second Example of Life

Presented by: Dr. Steven Benner  (Foundation for Applied Molecular Evolution)
Category: Science Colloquia   Duration: 1 hour and 30 minutes   Broadcast date: October 02, 2015
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Despite its apparent diversity, all of life on planet Earth is descended from a common ancestor, has essentially identical core molecular biology, and almost certainly has sampled selectively from the possible chemical solutions to the problems that biology presents. Therefore, we have available for study only one example of life. This makes it difficult to make any deep inferences about what life might look like in general, a difficulty that translates into comparable difficulties in recognizing life should we encountered it in a NASA space mission, or attempt to search for it by spectroscopy or radiotelescopy from a distant extrasolar planet. Only if we could find a second example of biology, one having origins independent of the biology that we know, will it be possible to do experiments that might dislodge the intrinsic "earth-centricity" hampers most thinking about biology. Mars might offer such a second biosphere. However, despite increasing likelihood that life will be found on Mars, the frequency with which material travels between Earth and Mars by natural processes is sufficiently high as to make not unreasonable the expectation that the Martian biosphere and the Terran biosphere also share common features. Analysis of spectroscopic and/or radio telescopic signatures from extrasolar planets, absent a "little green men" signal, is likely to be nothing more than controversial. Thus, we may be forced to turn to the remaining option to generate a second example of life: Create our own example in the laboratory. This talk will focus on these themes.