You are not currently logged in.
Access your personal account or get JSTOR access through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Unraveling the History of Arthropod Biodiversification
Richard C. Brusca
Annals of the Missouri Botanical Garden
Vol. 87, No. 1 (Winter, 2000), pp. 13-25
Published by: Missouri Botanical Garden Press
Stable URL: http://www.jstor.org/stable/2666206
Page Count: 13
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Current views of arthropod phylogeny are assessed in light of recent research in morphological and molecular phylogenetics, developmental biology, neurobiology, and paleontology. Recent fossil discoveries and molecular clock data inform us that arthropod diversification began in the Precambrian, and suggest that by the Cambrian the arthropods were already the most speciose metazoan phylum on earth. The combination of metamerism and jointed appendages (with intrinsic musculature), and the evolutionary potential of homeotic genes, has profoundly affected arthropod evolution and created many morphological homoplasies. Evidence strongly favors a monophyletic Arthropoda. Accumulating evidence supports a hypothesis that insects and modern crustaceans comprise a phylogenetic sister group, and that they, and perhaps also trilobites, chelicerates, and myriapods, all could have evolved out of an ancient crustacean stem line. Two implications of this hypothesis are that Crustacea comprise a paraphyletic taxon and insects may be viewed as "flying crustaceans."
Annals of the Missouri Botanical Garden © 2000 Missouri Botanical Garden Press