One possible reason we haven’t come across any off earth civilizations is because we’re among the first, or maybe even the first, to reach the point of looking for life elsewhere.
In case you’re wondering, the creature above is an orchid mantis and while it may not be as highly evolved and complex as we are, it is highly specialized.
A couple of scientists recently reverse engineered the time needed for the most basic parts of a gene to evolve into present day humans. They figured out the time frame is about ten billion years.
But the earth is less than five billion years old. Life began before the earth was formed?
That’s a pretty big discrepancy. Of course some aspects of evolution aren’t understood yet. Like maybe at times complexity was favored and evolution sped up. Or maybe simple precursors to life developed elsewhere and serendipitously arrived to jump-start life on earth.
Don’t forget, our universe is less than 14 billion years old. If these scientists are right about the process really needing ten-ish billion years to get from the most basic building blocks of life to how complex we humans are today, it could be why we don’t see anyone else out there, and may not for a while.