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RE: Steadman's review of Mesozoic Birds
John Pourtless wrote:
I have watched and participated in this fracas for about a decade now. And
in that time I have abandoned the thecodont hypothesis to which I
previously held, but I remain deeply troubled by the tone of the debate
amongst professionals and spectators such as myself.
I have to say (and it saddens me to say this) that this is part-and-parcel
of scientific debate. Every field of science has its topics that generate a
surprising amount of acrimony. To give another example... If you've tuned
in to the life-on-Mars debate, you'll know that central to this debate is a
certain Martian meteorite (ALH84001) found on Antarctica. This meteorite,
which is of undoubted Martian origin, contains microscopic crystals of
magnetite that are of a shape and size uncannily similar to those produced
biogenically by certain bacteria on Earth. The debate over whether the
magnetite contained in the Martian meteorite is indeed biogenic (and
therefore indicative of past or present life on the Red Planet) is one of
the most heated debates I have seen. (I have heard that some scientists are
no longer on speaking terms.)
Vitriolic debate also occurs in other areas of paleontology - as anybody who
is familiar with the opposing theories on the origin of _Carcharodon_ (the
great white shark) will attest to.
As for the birds-are-dinosaurs debate, this has to be one of the most
lopsided debates in the history of science. The notion that birds and
maniraptorans are not really theropods, but a separate lineage that evolved
independently from other theropods, is utterly bewildering. Mickey is
right: this does have an air of desperation to it.
It is nothing of the sort. I merley wish to indicate that cladistics,
much like molecular systematics, is not the universal panacea for
Molecular systematics actually employ cladistic methodology. Nucleotides
(for genes or RNA) and amino acids (for proteins) are the characters that
are used. But I would agree wholeheartedly that molecular analyses are not
the panacea for resolving phylogenies (for birds or anything else).
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