Flagellin and Tubulin Genes

Laurence A. Moran lamoran at bioinfo.med.utoronto.ca
Thu Oct 9 09:40:56 EST 1997

In article <61hpsj$m2j at net.bio.net> 
Jerry Learn <learn at u.washington.edu> writes:

>In article <61h4rc$g5e at net.bio.net>, Brian Foley <btf at t10.lanl.gov> wrote:

>>         First of all, the word "homologous" is supposed to mean
>> "derived from a common ancestor".  And this is usually a yes or
>> no answer.  There are not supposed to be differeing levels of
>> "homology".  However, people mis-use these terms in place of 
>> "similar" and and "similarity" so much, that I suppose we need 
>> to give up on the orignal definition.

>Here I go being orthodox again, but I have to disagree.  I don't think we
>should give up on the evolutionary definition of "homologous," just
>because people misuse the word.  There is a useful distinction between the
>two, as you point out.  I guess I will continue to try gently to correct
>people (mainly molecular biologists) when they misuse the words homology
>and homologous.

I agree with Jerry Learn - we should make the effort to inform our
colleagues. But you'd be surprised how angry they can get when you point
out the correct usage of "homology" and "similarity". I had a long and
pleasant discussion with one of our graduate students who was presenting a
poster at our Departmental poster day. The student was very receptive and
he asked for more information. I gave him a stack of articles that
discuss the proper use of "homology".

His supervisor phoned me the next day. Apparantly I had no right to
correct the poster or to make the supervisor look bad in the eyes of the
student. Besides, I was wrong - everybody uses "homology" to mean
"similarity". (No, the supervisor had not bothered to read the articles
that I had given the student. Still hasn't.)

Larry Moran

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