Linked Life Data

14724636

Source:http://linkedlifedata.com/resource/pubmed/id/14724636

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6971
pubmed:dateCreated
2004-1-15
pubmed:abstractText
Comparative embryology is integral to uncovering the pattern and process of metazoan phylogeny, but it relies on the assumption that life histories of living taxa are representative of their antecedents. Fossil embryos provide a crucial test of this assumption and, potentially, insight into the evolution of development, but because discoveries so far lack phylogenetic constraint, their significance is moot. Here we describe a collection of embryos from the Middle and Late Cambrian period (500 million years ago) of Hunan, south China, that preserves stages of development from cleavage to the pre-hatching embryo of a direct-developing animal comparable to living Scalidophora (phyla Priapulida, Kinorhyncha, Loricifera). The latest-stage embryos show affinity to the Lower Cambrian embryo Markuelia, whose life-history strategy contrasts both with the primitive condition inferred for metazoan phyla and with many proposed hypotheses of affinity, all of which prescribe indirect development. Phylogenetic tests based on these embryological data suggest a stem Scalidophora affinity. These discoveries corroborate, rather than contradict, the predictions of comparative embryology, providing direct historical support for the view that the life-history strategies of living taxa are representative of their stem lineages.
pubmed:commentsCorrections
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1476-4687
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
427
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
237-40
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Fossil embryos from the Middle and Late Cambrian period of Hunan, south China.
pubmed:affiliation
Department of Geology, Peking University, Beijing 100871, People's Republic of China. dongxp@pku.edu.cn
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't