On the Origin of Life

Observation One: The chemical elements which make up the bulk of all life; of all living things, just happens to be among the most common and abundant chemical elements in the Universe - CHON (Carbon; Hydrogen; Oxygen and Nitrogen). That life is basically composed out of the same very common stuff as the Universe itself can't be a coincidence. Life is NOT made up or out of exotic stuff like gold, silver, bromine, uranium, mercury, arsenic, etc.

Observation Two: Our galaxy is roughly ten billion years old. That's a lot of time for chemical reactions to happen in; for chemistry to strut its stuff from inorganic chemistry to organic chemistry to biochemistry.

Observation Three: There is a vast amount of real estate out there even in our own galaxy alone. One can even include interstellar space itself as part of that real estate since lots of organic chemistry / organic compounds have been observed in the depths of interstellar space as well as in meteorites and in comets which can bring organics to Earth (or any other environmentally friendly location).

Observation Four: There is a vast, vast range of environmental conditions within our galaxy. In fact, just think of the massive range of environmental conditions present within our own solar system.

Observation Five: Therefore, given the commonality of chemical elements between life and the rest of the Universe; extremely lengthy time periods; a wide variation in environmental conditions throughout, it's probably inevitable that just-so Goldilocks conditions giving rise to life would arise at least once. So there's no reason why Earth couldn't have been Ground Zero for life's natural origin.

Observation Six: It just takes one origin of life event to take hold for then that life can evolve and adapt and actually spread throughout the galaxy - there's more than enough time - via a concept called Panspermia.

There's actually some degree of evidence for Panspermia. First off, once the newly formed Planet Earth settled down, life arose extremely quickly, perhaps too quickly for a terrestrial in-house origin. Secondly, there's that Mars rock discovered on the Antarctic ice cap which contained about four separate and apart biological indicators. Lastly, there are microbes on Earth which even inhabit the insides of nuclear reactors and obviously can withstand massive doses of radiation; probably the last survivors after a nuclear war. There's no rhyme or reason for that to have evolved if these critters had a totally terrestrial origin and upbringing. But in space where radiation exists in abundance, well that's a different story.