Path: utzoo!attcan!uunet!oddjob!ncar!husc6!bloom-beacon!athena.mit.edu!ayermish
From: ayermish@athena.mit.edu (Aimee Yermish)
Newsgroups: sci.bio
Subject: Re: Evolution
Keywords: evolution, organelles
Message-ID: <6207@bloom-beacon.MIT.EDU>
Date: 14 Jul 88 22:35:52 GMT
References: <5944@bloom-beacon.MIT.EDU> <112@feedme.UUCP>
Sender: daemon@bloom-beacon.MIT.EDU
Reply-To: ayermish@athena.mit.edu (Aimee Yermish)
Distribution: sci.bio
Organization: Massachusetts Institute of Technology
Lines: 18

No one seems to have mentioned the idea about organelles having
previously been independent prokaryotes that entered into symbiotic
relationships.  Several organelles (for example, mitochondria, which
do cellular respiration (for you CS-types, a serious win when it comes
to using glucose efficiently), and chloroplasts, which do
photosynthesis (another big win, 'cause it making food is easier than
finding it, and CO2 is cheap)) have their own DNA.  I'm not sure about
the chloroplasts, but the triplet code for amino acids is slightly
different in mitochondrial DNA.  What exactly that means is still
somewhat up in the air, though.  

--Aimee


------------------------------------------------------------------
Aimee Yermish		ayermish@athena.mit.edu
MIT couldn't care less about anything I say. 
(as long as I finish that last paper...)