[Taxacom] SINES, LINES and chromosonal rearrangements

[Kenneth Kinman]

Hi John,
     Yeah, I latch onto whatever new technology can offer, and if it
proves even more reliable all the better.  But it's simplistic and
misleading of you to characterize it as totally abandoning the old and
leap-frogging to ONLY the new.   
      Likewise, it would simplistic of me to say that newer
morphological data (made possible by electron-microscopes) totally
leap-frogged over all previous morphological observations.  However,
like molecular data, the newer morphological data is often extremely
important.   
      The point is that you can have misleading (homoplastic) data
whether it is molecular or morphological.  This is especially true of
the simplest of molecular data (single base changes) and even some
simple morphologies (possesion of two eyes, which has evolved
independently in many metazoans), or fins for swimming (many amniotes
reverted back to swimming in the ocean with arms evolving back to
fin-like appendages---various Mesozoic reptiles, penguins, and
cetaceans). 
       I don't think your orangutan-hominid morphological data is as
broadly simplistic as possession of two eyes or even possession of fins
for ocean swimming, but I still think it is homoplastic in the sense
that many morphologies can be developmentally related (even from just
one change in a development gene) in ways that we are only beginning to
understand.
      So that is why I will tend to trust whole genomes (properly
analyzed) over most morphological data.  It's not leap-froggjing to the
new and totally ignoring the older data, but just following the newer
data (molecular or morphological) where it overturns the older data
which turned out to be homoplastic.  Some of the older morphology
continues to hold up (such as possession of a nucleus in eukaryotes),
but morphology has its pitfalls (and I suspect an orangutan-hominid
clade is one of them).  Whole genomes (and especially the development
genes) are where the answers will be most often found, and then new
(often overlooked) morphologies will be found that are congruent with
them.  It is working fairly well for angiosperms, so I have no doubt it
will work for the apes as well.        
          -------------Ken Kinman      
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John Grehan wrote:
       It was interesting to see ken now latch onto particular kinds of
molecular data being more 'reliable'. That's a shift from "molecular
data=DNA) being more reliable than morphogenetic data. The history of
molecular approaches has witnessed a continual leap frog as each
molecular evidence was first touted as the refutation of morphogenetics,
and then as its own inherent faults come to light the molecular
theorists jump onto the next 'breakthrough' technique - SINE's etc being
among the latest) and denounce the former 'proofs' as inadequate, but
that will not finally be solved by the new technology.