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Unformatted text preview: SETI : Vali January-25-10 1:40 PM Despite morphological diversity of terrestrial life it has the same basic biochemical and genetic relatedness We initially search for life-forms that are like us For now, we conduct the search on other planets It is unlikely we will be able to directly access any evidence we found We have two candidates that are promising targets, Mars and Europa Still searching for water and carbon-based life How to search for life on other worlds 1.There is no generally accepted definition for life 2.Ecological requirements a. Carbon b. Water c. Biogenic elements 1.Organic matter of biological origin can be differentiated from other organic matter because life preferentially selects and uses a few specific organic molecules which may be a general feature of all life. Finding a large, complex, recognizable molecule, like chlorophyll, would be good evidence. Smaller organic molecules, however, the distinction between biochemicals and abiotic organic matter is not found in a particular molecule, but in considering the pattern of the many types of molecules in a sample. 2.Microbial life is more probable and widespread than large multicellular life. For most of Earth's history, life was microscopic, and even today, dominates the planet in the most diverse nand extreme environments. On Earth, all large multicellular lifeforms require oxygen and we might expect this on ohter planets....
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This note was uploaded on 10/23/2010 for the course ANAT Anat 182 taught by Professor Vali during the Winter '10 term at McGill.
- Winter '10