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Re: going offlist on Protista, bacteria



You wrote:
Birds are not superior to dinosaurs, so why give them a "Class" of their
own.
I responded:
Easy:  because they are obviously different.
Your rejoinder:
Deja vu all over again.
No, they are not.  Birds are no [more ( I assume)] different from
dromaeosaurids than bats are from monkeys.

Fair enough.  There has been a decision that the similarities between bats
and monkeys (and other mammals) are more important than the differences.
There has also been a decision that the resemblances between dinosaurs
(excluding dromaeosaurids) and dromaeosaurids are greater than the
resemblances between dromaeosaurids and birds (even considered as a subset
of dinosaurs).  Therefore, dromaeosaurids are dinosaurs.
The discussion in the last paragraph concerns the question of the proper
placement of dromaeosaurids.
Another issue is whether the great majority of the entire 900 (or whatever
it is now) species of dinosaurs all have enough differences from birds on
the one side and lizards, snakes, crocs, etc. on the other to be considered
a separate group.
Intuitively, most people would say, 'Yes.'
Contradicting this intuition is a different logic which looks more closely
at the small differences at the initial stages of evolution than at the
substantial differences which accumulated later.
Without changing your view of which is correct, I hope you can agree that
these are alternate logics based on reasonable premises, and that the more
intuitive is not just the inappropriate application of a concept like
superiority.
I commented because you observed:
<Birds are not superior to dinosaurs, so why give them a "Class" of their
own.  Go way back to the base
of the Aves, and the differences between birds and dinosaurs resolves into
one or two evolutionary innovations.>
Please recognize that arguing birds are in a different group from dinosaurs
is not just attitudinizing; it can involve a reasonable but different way of
looking at the same evidence.  The difference is emphasis, not fact.