Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1989-9-19
pubmed:abstractText
The divergence between monocots and dicots represents a major event in higher plant evolution, yet the date of its occurrence remains unknown because of the scarcity of relevant fossils. We have estimated this date by reconstructing phylogenetic trees from chloroplast DNA sequences, using two independent approaches: the rate of synonymous nucleotide substitution was calibrated from the divergence of maize, wheat, and rice, whereas the rate of nonsynonymous substitution was calibrated from the divergence of angiosperms and bryophytes. Both methods lead to an estimate of the monocot-dicot divergence at 200 million years (Myr) ago (with an uncertainty of about 40 Myr). This estimate is also supported by analyses of the nuclear genes encoding large and small subunit ribosomal RNAs. These results imply that the angiosperm lineage emerged in Jurassic-Triassic time, which considerably predates its appearance in the fossil record (approximately 120 Myr ago). We estimate the divergence between cycads and angiosperms to be approximately 340 Myr, which can be taken as an upper bound for the age of angiosperms.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-16593540, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-17246206, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-17788489, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-2469937, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-2901763, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-3169573, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-3368328, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-3447015, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-3480529, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-3916709, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-6089124, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-7372356, http://linkedlifedata.com/resource/pubmed/commentcorrection/2762323-7463489
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0027-8424
pubmed:author
pubmed:issnType
Print
pubmed:volume
86
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6201-5
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Date of the monocot-dicot divergence estimated from chloroplast DNA sequence data.
pubmed:affiliation
Center for Demographic and Population Genetics, University of Texas, Houston 77225.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.