Earth was created about 4.5 billion years ago, first life appeared about 4 billion years ago. So as soon as Earth was cool enough for complex life molecules to assemble, there they were, complete and ready to go. Now fast forward 4 billion years to the present day and we still have that same original form of DNA populating the planet, but we have not (it seems) produced any new complex life molecules in all that time, it’s just the same DNA base, all the way back to the beginning. That is ridiculous. It is ridiculous, both in that life arrived so quickly on Earth, (almost, it seems, as quick as was chemically possible), and it’s also ridiculous that there has been no DNA successor/improvement/upgrade for 8 times the wait for first life to appear.The life base is still the same DNA double-helix structure. There is only one logical explanation taking all of this into account. The first life molecule(s) came from off planet, either through panspermia, or seeded by extraterrestrials. Whatever the actual origin, an off-planet source for DNA means that there is life elsewhere in the Universe, and it will be DNA-based life as well!
To believe that DNA could have suddenly appeared on Earth, complete, formed by natural processes, as soon as Earth was cool enough – and yet there has been no sign of any other sudden appearances of life-molecules in the 4 billion years since then, is not a very scientific observation of the facts.
