I suspect life is everywhere. I base this on the fact that our DNA complexity is currently around 2.5-3 billion years older than the planet. Intelligent, and more importantly multicellular, life is the variable that can’t be determined quite yet. The step from single cellular life to multicellular life has happened a few times on Earth, but all of those times have been in the last billion years. I personally believe that is because we are just about as young as intelligent life could possibly be, since the universe was actively hostile to life prior to about 7.5 billion years ago.
I also like the idea that for a few hundred million years (around half a billion years after the big bang) the entire universe was the correct temperature for life to have developed literally everywhere and anywhere.
DNA complexity is currently around 2.5-3 billion years older than the planet
That doesn’t mean DNA existed before the earth. It is possible that at low complexities different factors dominated the exponential increase assumed to reach that figure
“I base this on the fact that our DNA complexity is currently around 2.5-3 billion years older than the planet.”
That isn’t a fact, it’s extrapolation based on a simple exponential fit to rough estimates of present-day genome complexity.
Even if we knew complexity always grew exponentially, which we don’t, small changes in an exponential fit will greatly affect an extrapolation.
And we don’t know what the genome complexity was of the first prokaryotes, not to mention any number of forms of life that might have gone extinct between then and now.
For example, there was a group a of multi-cellular life that flourished long before the current group, but they lived for millions of years. We’ll probably never know anything about their genetic complexity.
I suspect life is everywhere. I base this on the fact that our DNA complexity is currently around 2.5-3 billion years older than the planet. Intelligent, and more importantly multicellular, life is the variable that can’t be determined quite yet. The step from single cellular life to multicellular life has happened a few times on Earth, but all of those times have been in the last billion years. I personally believe that is because we are just about as young as intelligent life could possibly be, since the universe was actively hostile to life prior to about 7.5 billion years ago.
I also like the idea that for a few hundred million years (around half a billion years after the big bang) the entire universe was the correct temperature for life to have developed literally everywhere and anywhere.
That doesn’t mean DNA existed before the earth. It is possible that at low complexities different factors dominated the exponential increase assumed to reach that figure
“I base this on the fact that our DNA complexity is currently around 2.5-3 billion years older than the planet.”
That isn’t a fact, it’s extrapolation based on a simple exponential fit to rough estimates of present-day genome complexity.
Even if we knew complexity always grew exponentially, which we don’t, small changes in an exponential fit will greatly affect an extrapolation.
And we don’t know what the genome complexity was of the first prokaryotes, not to mention any number of forms of life that might have gone extinct between then and now.
For example, there was a group a of multi-cellular life that flourished long before the current group, but they lived for millions of years. We’ll probably never know anything about their genetic complexity.