Water on Mars and life on Earth
OPINION: It would have to have been a very special chemical soup. The first one, I mean. The one from which the first living cell spontaneously arose, and then managed to reproduce. I know this because I've been reading about what it takes to build a living cell, and comparing notes with what scientists have found in the water on Mars.
It's all mischievously complicated, here at least. Every time scientists think they have the recipe right to build life in its most basic form, a new discovery throws the equation out. We need chemicals, and lots of them. But we need them in just the utterly precise combinations, and utterly precise amounts, meeting in utterly precise ways, or chemical warfare ensues.
We need, for example, all the bits that make up sugars, but sugars are sensitive wee things and can only form in a certain atmosphere. Unfortunately, the atmosphere in which sugars thrive kills the mood for another of life's building blocks: amino acids. They simply refuse to form unless they get to hang out in acid.
But if we give in and allow the amino acids what they want, they'll start flinging certain compounds at the sugars, tantamount to bombing the latter to smithereens.
Apart from the constant threat of chemical warfare breaking out at every level of the encyclopaedias-worth of reactions and chemicals needed for life, there's another problem.
The bits need each other to make each other. Take DNA, for example. It's one of those really complicated, needy friends with extraordinary giftings whom we all come across in life. In fact, it takes 50 (that we know of so far) proteins just to understand what DNA is trying to say, and others to carry out the instructions. But DNA itself holds the instruction manual for making its 50 translators. So how on Earth, without translators present, did the builder friends (whom DNA also holds the instruction manual to make) first know how to make the translators that would enable the builder friends to get on with their jobs? And where did the builders come from without translators to help?
It gets worse. Much, much worse. Even the "simplest" forms of life we know about are high-precision factories with everything from containment areas for chemical reactions to high-tech manufacturing robots to headquarters decked out with the world's most efficient and powerful hard drive. And specialised workers on every floor help to keep the whole thing going. Take out one bit and it all stops working. Try building it section by section and you'll find the missing bits are needed to make the first bit.
The chances it will all fall together by accident are, unless you wish to ignore science, nonexistent. And that is exactly why life is so very special, on earth or whatever place (even the virtually impossible option of Mars) that it pops up. That is why we must do our best to protect, foster and care for it right from the first moment it forms, through to the last breath that it takes. It's not an accident and it is not random. You and I are here by design.