Who said they were lichen spores?
I thought it was Fred Hoyle who said that the ancient protobird fossil
was a hoax? Of course I am sure Wick supported his claim.
My concern is that most scientists dismiss Wick to the point that
they may ignore a real discovery. I don't mean they need to jump
every time he makes a claim, but there should at least be some kind
of independent group of scientists who examine the more interesting
cases.
The BBC has a page on the pros and cons of life having come from comets:
http://www.bbc.co.uk/science/space/life/beginnings/comet.shtml