well fine, then we can look at THOSE bacteria....
I don't think things fossilize over a few weeks.....
of course you would....because the terrestrial bacteria would all have evolved, wouldn't they?.....
The terrestrial bacteria would have evolved into what?
Look at the bacteria that MAY have absorbed the extra terrestrial bacteria? What good do you think that will do? The paper expects that the extra terrestrial bacteria should be similar in its makeup to what we find on earth.
Fossilize merely means that some remnant of the organism is preserved.