Lophophorates prove likewise variable
Article Abstract:
Kenneth M. Halanych and colleagues have used phylogenic reconstruction based on ribosomal RNA gene sequence to demonstrate that lophophorates are grouped firmly within the protostomes. Previously considered grouped with deuterostomes, the RNA shows that there is no special relationship between lophophorates and deuterostomes and that lophophorates are actually advanced protostomes. However, critics question the use of one RNA sequence analysis to reclassify relationships especially when pterobranchs are grouped separately despite their similarities to lophophorates, making lophophorates a double independent evolution according to Halanych.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
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The molecular explosion
Article Abstract:
An ingenious method, which helps build phylogenetic trees without much multifurcation, involves determination of sequences in 69 complete 18S rRNA and removal of the quickly evolved phylogenies, as these are the ones that lead to multifurcation. This technique has been extremely useful in studying the Cambrian 'explosion,' which resulted in various metazoans by developing a fossil rocks-calibrated molecular clock.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
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What remains, however improbable...
Article Abstract:
Modern palaeontologist face difficulties while identifying the species having no relation with modern species. Case of three small teeth fossils of mammals from the early cretaceous of Morocco and problems in interpretation is presented. Problems faced by the palaeontologists in identifying phosphatic, tooth-like microfossils are also presented.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1995
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