Is it possible that all life on earth including human life originated from alien DNA?
Hello fellow Alpha Centurians!
Ian here for DNews to talk about the meaning of life, kinda.
Let’s cut to the chase: we have a pretty good idea that life on Earth popped into being
around three and a half billion years ago.
Sure, back then, life wasn’t particularly glamorous -- unless being a single-celled
prokaryote living in a pool of organic goo is your idea of “glamor” -- but that’s
how we think our planet's biosphere began.
There is, however, a lot of debate surrounding how life came to be and where life’s building
blocks REALLY came from.
Were all the prebiotic chemicals already here on Earth, laid out like the ingredients to
a biological cake?
Or did these chemicals come from elsewhere?
A tantalizing clue recently came from Europe’s Rosetta mission that has been orbiting Comet
67P for the past 2 years.
In addition to the incredible number of discoveries Rosetta has made, the detection of the amino
acid, glycene in the comet’s coma -- basically the dusty, gassy atmosphere surrounding the
comet -- has excited astrobiologists.
This is the second comet known to be carrying the amino acid.
In 2004 it was found on comet Wild-2 (“Vilt-2”), which is exciting because we know that glycene
is one of the essential building blocks for life and we know that finding it in more than
one place isn’t a fluke.
Not only that, but Rosetta’s comet also contains other compounds that form the building
blocks of life, including the element phosphorous that is the backbone of DNA and RNA, reaffirming
comets as potential “seeds” for life on planetary bodies.
So we have a pretty good idea that the ingredients for life can be found anywhere and could be
transported to habitable worlds via comets.
But what if life ITSELF could be transplanted from one planet to another?
This concept is known as “panspermia” and it’s a hypothesis that really puts your
imagination into a spin.
For argument’s sake, let’s say life formed on Earth first.
In the billions of years of evolution, Earth has been hit by countless massive meteorite
strikes.
Should these impacts have been powerful enough, chunks of Earth’s crust would have been
catapulted into space.
As the planet is covered in life, some of these chunks of Earth rock would have likely
had bacteria hitching a ride.
Should these hardy microbes survive for long enough -- protected deep inside their rocky
interplanetary vehicle -- could they end up crashing onto another world, survive the impact
and take up home?
This is hypothesis is known as “lithopanspermia” and though it’s a highly speculative means
of life hopping from planet to planet, we do know that rocks have travelled across the
solar system.
For example, Mars meteorites have been found on Earth -- massive Martian impacts have kicked
pieces of the red planet into space only for those samples to fall onto Earth, sometimes
thousands of years later.
There’s even been some excitement surrounding the possibility that fossilized bacteria might
exist within these meteorites, though further analysis has shown these “fossils” are
actually just mineral deposits.
Another hypothesis called “necropanspermia” even suggests that for life to spread from
planet to planet the organisms in a meteorite needn’t be alive when they arrive at their
destination -- their fossilized DNA may create a template by which organic chemicals can
latch onto, spawning life.
In this case, rocks that have traveled interstellar distances may seed life in other star systems.
And then there’s an even more “out there” hypothesis that some advanced alien civilization
seeded protoplanetary disks around young stars with their own special blend of amino acids
to create cosmic life in their image.
This sci-fi possibility is called “directed panspermia.”
Although there is currently zero evidence that panspermia is a “thing” we DO know
that the ingredients for life is everywhere and it’s possible that the biology that
kick-started life on Earth didn’t, in fact, originate here.
If you want to find out how we might be CURRENTLY polluting the solar system with our germs,
check out my video on dirty Mars rovers:
Do you think life as we know it was actually seeded from space?
Let us know in the comments down below and don’t forget to subscribe to DNews!