Jim Perry said:>>
>> At the risk of sending something that most of us might know...
There's no risk here. I 've always thought that fibers were more
specialized and evolved from tracheids. Also I thought that the
first vascular plants had tracheids not fibers. Please set me
straight. What about Rhinia and Cooksonia sp. are there now fossils
that pre date these early plants. I took Paleo-bot in the
Paleozoic !
> The evolution of xylem tracheids is presumed to have occurred as a result of
> modification of fibers, and subsequent to that, vessel members to have evolved
> from tracheids. Inasmuch as early land plants were likely thallose, and were
> in fact probably more accurately described as amphibious, any development of
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Dave Haas
Department of Natural Sciences
Fayetteville State University
Fayetteville, NC 28303
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"More than any other time in history, mankind faces a crossroads. One
path leads to despair and utter hopelessness. The other, to total
extinction. Let us pray we have the wisdom to choose correctly." -
Allen Konigsberg.
