Are we the first, or one of the first civilizations in the galaxy?

[Humanist_Activist]

I was thinking about this since the so called "megastructure" was discovered. Its likely its a natural phenomenon that was previously unknown, or has another, equally mundane, explanation, or it could be evidence of an alien civilization, who knows.

There's a relatively common trope in science fiction of "progenitors". Civilizations that rose to power millions or billions of years ago, in most sci-fi, they became extinct or are hiding.

But how likely is that to be true?

The universe is young, being about 13.82 billion years old, an unimaginably long time. However, remember this, it took several "generations" of star formation and violent star death before rocky, metal rich planets could form. Our sun was born about 4.6 billion years ago, from a metal and silica rich molecular cloud that was able to form us.

The fact is that it seems likely that the sun was one of the earliest possible solar systems to form in the galaxy that has the conditions necessary for life and civilization, with the right mix of elements to allow Earth to form.

Add to this the fact that for most of Earth's existence, life was simple microbes and amoeba, which may have arose within 500 million years of Earth's formation, perhaps even sooner after it cooled. But that leaves 3 to 3.5 billion years before multicellular life arose, after the great oxygenation events in the Pre-Cambrian or so. From there, it still took about half a billion years for civilization to arise.

Should we expect another planet to develop civilization quicker than ours?

Could we be the progenitors? It would be one explanation for the Fermi Paradox, perhaps we are the ones who are supposed to be, thousands of years from now, a galaxy spanning civilization. Assuming we don't destroy ourselves first, and the ruins discovered by others in the far future, pondering what we must have been like.