Old Favourites from the Elder Poets, with a Few Newer Friends, a Selection by M. Sharpe

It shouldnБЂ™t happen, but somehow in nature it does. The actual chemistry of all this is a little arcane for our purposes here, but it is enough to know that if you make monomers wet they donБЂ™t turn into polymers-except when creating life on Earth. How and why it happens then and not otherwise is one of biologyБЂ™s great unanswered questions. One of the biggest surprises in the earth sciences in recent decades was the discovery of just how early in EarthБЂ™s history life arose. Well into the 1950s, it was thought that life was less than 600 million years old. By the 1970s, a few adventurous souls felt that maybe it went back 2.5 billion years. But the present date of 3.85 billion years is stunningly early. EarthБЂ™s surface didnБЂ™t become solid until about 3.9 billion years ago. БЂњWe can only infer from this rapidity that it is not БЂdifficultБЂ™ for life of bacterial grade to evolve on planets with appropriate conditions,БЂ«Stephen Jay Gould observed in the New York Times in 1996. Or as he put it elsewhere, it is hard to avoid the conclusion that БЂњlife, arising as soon as it could, was chemically destined to be.БЂ«Life emerged so swiftly, in fact, that some authorities think it must have had help-perhaps a good deal of help ...»