Understanding evolution problems

Richard.Zander at MOBOT.ORG Richard.Zander at MOBOT.ORG
Thu Mar 4 15:32:33 CST 2004


It's a warmer argument now. Good.

There have always been more young Turks that are wrong than those who were
right. Hopeful monster new paradigms include those of Lysensko, Velekovsky,
Madame Blavatsky, and the like, remember those? all of which gain followers,
all of which attract money, and all of which fail for reason.

What happened to the phenomenal advances predicted for phenetics? chromosome
numbers? biosystematics? They all got relegated to their proper place.
Cladistics and statistical phylogenetics have a proper place, but right now
they are grown way out of proportion to their actual utility.

Eventually, it will be found that the reliability measures presently given
to details of branch arrangements are grossly inflated. Here's why:

Any measure of reliability, to be useful, needs to be coupled with a measure
of risk. We are betting our science, so we want really high measures of
reliability, like standard 95% or 99% condidence limits. The measure of
reliability, if we are to act on it, should reflect all factors that affect
the outcome (the particular branch arrangment of interest). Thus, the
probability of the branch arrangment being correct must be multiplied by the
probability of the sequence alignment being correct, and that by the
probability of no sample error, and that by the probability of no
differential lineage sorting, and that by the probability of each and every
other variable and regularity assumption not affecting the result.

With morphological data, we see Besseyan cactuses of phylogenetic trees,
because details are vague but relationships at a distance on a tree we feel
can bet on. I believe that the same will prove true with molecular data: we
have more Besseyan cactuses of relationships. This is not bad since we can
use the probability of the morphological arrangment being correct as a
Bayesian prior for the probability of the molecular arrnagement if the same
being correct, and increase the measure of reliability. This may sometimes
happen.

Of course some relationships and branch arrangements are accepted or are
uncontroversial. True advances are made by demonstrating the reliability of
new results involving problematic relationships or branch arrangements. I
have see little of this in the phylogenetic literature to date.

I will repeat here on Taxacom that in order to scientifically contradict or
at least put in proper perspective the rather arrogant arguments of a
phylogeneticist, you have pretty much become one.

______________________
Richard H. Zander
Bryology Group
Missouri Botanical Garden
PO Box 299
St. Louis, MO 63166-0299
richard.zander at mobot.org <mailto:richard.zander at mobot.org>
Voice: 314-577-5180
Fax: 314-577-9595
Websites
Bryophyte Volumes of Flora of North America:
http://ridgwaydb.mobot.org/bfna/bfnamenu.htm
Res Botanica:
http://ridgwaydb.mobot.org/resbot/index.htm




-----Original Message-----
From: Michael Ivie [mailto:mivie at GEMINI.OSCS.MONTANA.EDU]
Sent: Thursday, March 04, 2004 1:43 PM
To: TAXACOM at LISTSERV.NHM.KU.EDU
Subject: Re: [TAXACOM] Understanding evolution problems


This delightful discussion recapitulates those of the Scala naturae
adherents that objected to the errors in Lamarck's discovery of evolution,
the Earth Centered group that objected to the fad of Galilean mobilists,
the Flat Earth League, the stabilist diatribes against the crazies
that proposed continental drift, and those that objected to complex cords
in Baroque music.  All of these and many other deadenders died expecting
to have everyone come back to their view while the young turks burned in
hell.  In the end all these r eactionary "controversies" were solved the
same way this one will -- eventually all the fuddy duddies living
in past will die off, and everyone will laugh that they ever existed.

Whenever a group of young turks (in this case, phylogenetisists) overturn
an established apple cart (the Mayrian "evolutionary" taxonomists and
Pheneticists), there is a predictable objection from the old guard, and
always a few of the next generation who hang on to the old ideas for some
reason or other (invested, slow, lack of imagination, viserally
conservative, intellectually infelxible, or whatever).  This is how
science has and always will progress.  However, when someone finds
themselves in this situation, they should really reexamine their stance.
We can use the examples of our greatest scientists to find our way.  Look
at Charles Michener, who moved beyond the point where he was invested,
into the new and superior paradigm that replaced the old one, and is
universally revered.

As I teach it, good taxonomists are very, very valuable, but not all
good taxonomists are systematists.  Some good systematists are not good
taxonomists.  However, all real modern systematists are phylogeneticists.
Not all phylogeneticists are strict cladists.  For instance, my optimal
solution is a monophyletic classification, but I recognize that if the
sister-group of all the rest of life is a single species, and single
species cannot by themselves constitute a monophyletic group, then the
rules need to be bent to make it work.  I do teach that there are other
views, and that they are wrong.

And Dr. Greham, If all the really smart people reviewing your proposal
think it is bunk, perhaps it is not they that are wrong?  So says Occam's
razor.  Parsimony may not always be right, but it is worth thinking about.
Remember, evolutionary studies show that pathways that only take root and
diversify in isolation on small isolated islands are not usually very well
adapted when placed into global competition.  They should be maintained
as examples of a different path, and valued as examples of evolutionary
diversity, but never confused with something really useful.

Our system of reviews by NSF and other granting agencies have proven very
good at rewarding successful paradigm challenges, and also very good at
recognizing bunk.  There are rare exceptions, but the exceptions prove the
rule.

OK, let the attacks begin.

Mike




More information about the Taxacom mailing list