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Re: Making Up Names _versus_ Emending Names
Thanks for your clarification! You observed:
<I meant that Linnaean categorization was based primarily on
differentiation, rather than similarity, whereas it is the opposite in
modern phylogenetic classification. The relationship of two organisms cannot
be tested by the lack of features...>
I appreciate that relative subjectivity has been removed as an issue.
Assuming that neither approach being compared is based on simple feeling or
intuition, but that both produce logical hypotheses to be tested, consider
the following two statements:
Two very similar species are closely related.
Two very different species are not closely related.
At first glance, both statements appear self-evident. However, thanks to
convergence and to the sometimes rapid pace of evolutionary change, I'm sure
that you could think of specific examples proving each statement false.
So, if you are going to base a system of nomenclature on relationship, you
would have to have confidence that you could limit what are termed in
another context 'false positives' (untrue apparent close relationships) and
'false negatives' (true close relationships which are not easily
A descriptive approach would not have to be immediately concerned with this
problem, because that which appears to be substantially different would be
distinguished by name. Relationship could eventually change a name
generated by description (similar to a 'false negative'), but any such
change would be slow.
In this context, when I said:
You aren't surprised, though, when differentiation does respond to a
substantially different evolutionary origin, are you?
and you replied:
No. I'm rarely surprised in this case because I hold no
paradigms to be true. If birds are not descdant from any
theropod or dinosaur, or whatever, I won't be surprised, I hold it neither
true nor false, but as a strict possibility; just
that this one has a greater probability of being actual, versus the
This certainly would be a good argument for not basing a system of
nomenclature on a slightly better probability, because as you say this makes
But then you argue:
Similarly, I hold that an organism is better represented in a
phylogeny if its ancestors are considered as part of the
When you say 'lineage' I think you mean rules for naming? Because names
must respond to a change in identified ancestors, you would in fact expect
to see many changes in names, no?.
You seem to be sacrificing stability for teaching about views of ancestry.
If I read a separate post correctly, you'd even be including the name of a
theorist and publication date in the 'emended' scientific name of an animal.
I'd hate to be a textbook publisher using this system if I'm understanding
you correctly. I thought map makers and geography texts had a problem after
the Soviet Union broke up...
I think I've understood part of your argument, but probably not all. If you
could extend it a bit further in reference to stability I'd appreciate it.
Thanks for looking at the issue in these terms so I can see what you're