By now I have no doubt you heard of NASA’s announcement that there could be 7 planets that have the ability to support life only 39 light years away. If you haven’t heard check out the article from NASA’s Official Site.
That’s obviously amazing. Any chance of meeting alien life is incredibly cool but how could life on those planets exist? How did life here on earth even begin? That’s what I hope to answer for you.
Everything you will be told in this blog is based solely off of Evolution.
The main theory most biologists accept is that it all began from 1 molecule billions of years ago kept safe in a jelly-like a membrane. We have no way to know what type of molecule it was but the safest bets are RNA, DNA, or Amino Acids. The reason scientists expect it to be one of these to be the first biological molecule to evolve is because everything has those three things. Plants, animals, fungus, bacteria, even humans all have those three molecules inside us. Most likely RNA is what evolved first because it has a unique ability. It can replicate itself indefinitely. RNA is made up of three different things. a phosphorus molecule, a sugar molecule and a base. There are four different types of bases G, U, C, and A. Your genetic code is made from those 4 letters in a specific order; by looking at thousands of these strands scientists can see the genes for red hair, language, and everything else that makes up who you are.
Because of geology, we know that life began in the Archean aeon that lasted between 4 billion and 2.5 billion years ago and the Proterozoic aeon that lasted from 2.5 billion to 251 million years ago. Over the course of billions of years and multiple mass extinctions, human beings evolved from
and finally to this
Between each on of those pictures, there is millions of years and millions of different species. Over the 4.5 billion years the earth has existed 99.9% of life has gone extinct and yet somehow we made it. We took what evolution gave us and shaped the world to what we wanted. Life is a finicky thing that can all stop in an instant. We still don’t know what the initial catalyst for life is. The first RNA could have sprung up out of nothing, it could have been a comet impact that brought biological molecules from another solar system, for all we know it could have been the science experiment of some alien lifeform. (probably not that last one).
The most amazing thing about humans existing is if just 1 small thing happened differently millions of years ago we may not exist. You literally only exist because of an ancient rat-like creature managing to find shelter during a storm or a sea creature escaping a carnivore at just the right moment. Every piece of the evolutionary puzzle fell right into place so you could be here. Maybe applying for that new job or asking your crush on a date isn’t such a big deal after all?
Now you know.