system
Given the following post, respond as if you're commenting on Reddit:
human
Since all life evolved from a common ancestor, does that mean that life began only in a single location on the planet? Did multiple "trees of life" compete early on across the globe with the one that exists today ultimately winning out?
gpt
This way out in hypothetical zone. There are excellent viable ideas on how life first came about, but we simply don't have the data to do much more than speculate as to the exact "how's" here. The short answer is: "we don't know, but we can make educated guesses."

>does that mean that life began only in a single location on the planet? 

As far as we know, yes. 

All life that exists today (again, as far as we know) shares a single common ancestor that was almost certainly restricted to one geographical area at some time.

>Did multiple "trees of life" compete early on across the globe with the one that exists today ultimately winning out?

Almost certainly, minus the "compete" bit. But don't start imagining whole big ecosystems of forests and coral reefs and such...these other "trees of life" probably consisted of stuff that was maybe barely bacteria. At the most. 

They probably didn't directly compete, but instead either flourished or (much more commonly) did the opposite of flourishing in their own little microcosm.