Came life from space?

Arlin Stoltzfus arlin
Thu Oct 12 19:47:41 EST 1995

mg16 at kimbark.uchicago.edu (Mark D. Garfinkel) wrote:
>In article <450u12$9hi at unix.sbu.ac.uk>,
>matthias  <hammm at trier.fh-rpl.de> wrote:
>>the nearest star to the sun
>>is several light-months away.
>	Only if you define "several" to be as large as "fifty." Proxima
>Centauri and the Alpha Centauri multiple-star system are taken to be 4.1
>and 4.3 light-years away, respectively.
>	One of the problems with the galactic panspermia hypothesis, aside
>from having no real explanatory power, is that it requires spores, for
[clip, clip]

I heartily agree with everything that Mark said.  I would just like to comment
on this issue of explanatory power.  Even if interstellar transfer of cells
could be demonstrated to be feasible (i.e., even if there were "hardy little
buggers" that could survive the interstellar journey) the panspermia hypothesis
would still not explain the origin of cellular life.  The panspermia hypothesis
"explains" the origin of cellular life *on earth* by dodging the origin of
cellular life and consigning it to a black box.  Cellular life came from this
black box, which was located in some other part of the universe, then cellular
life was transported to earth.  

It is fair to say that the panspermia hypothesis "explains" how cellular life
on earth began.  But it does this without offering the slightest insight into
how cellular life began.  Instead of answers, we are left with the same
questions-- what were the first replicating entities?, how did the cell
membrane first arise?  did DNA replace some other genetic material?, etc., etc.
Are we supposed to believe that it was somehow *easier* to evolve life on
another planet?  If so, why?    

Arlin Stoltzfus
Department of Biochemistry
Dalhousie University
Halifax, Nova Scotia B3H 4H7 CANADA
arlin at ac.dal.ca 902-494-3569 (phone) 902-494-1355 (fax)

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