Fred Hoyle and Wickramasinghe postulated that microbial life could be transplanted between planets by being included in dust particles, micrometeorites or other stone fragments. Modern folk call it lithopanspermia...usually caused by high impact events.
Now,,,if we find organisms in space or other planets we may not be sure they evolved there. From what I understand. Hoyle was convinced that life on earth was seeded from space as he saw the chances of life evolving here on Earth from raw elements impossible without intelligent intervention. He never tried to answer the question of where exactly did life actually evolve from. Some research group wants funding...
Saying that life on Earth came from another planet, simply kicks the can down the road.
Where did THAT life come from?
And if you say another planet, then where did THAT life come from?
It’s a non-answer, and a way for a ‘scientist’ to avoid answering the obvious.
There is absolutely no evidence of life outside the Earth’s sphere of influence. None, zero, zip, nada.
If there were, it would be everywhere...........................