The rise of the rhizosolenid diatoms.
The 18S ribosomal DNA molecular phylogeny and lipid composition of over 120 marine diatoms showed that the capability to biosynthesize highly branched isoprenoid (HBI) alkenes is restricted to two specific phylogenetic clusters, which independently evolved in centric and pennate diatoms. The molecular record of C25 HBI chemical fossils in a large suite of well-dated marine sediments and petroleum revealed that the older cluster, composed of rhizosolenid diatoms, evolved 91.5 +/- 1.5 million years ago (Upper Turonian), enabling an accurate dating of the pace of diatom evolution that is unprecedented. The rapid rise of the rhizosolenid diatoms probably resulted from a major reorganization of the nutrient budget in the mid-Cretaceous oceans, triggered by plate tectonics.
Damsté
Jaap S Sinninghe
JS
Department of Marine Biogeochemistry and Toxicology, Royal Netherlands Institute for Sea Research, Post Office Box 59, 1790 AB Den Burg, Texel, Netherlands. damste@nioz.nl
Muyzer
Gerard
G
Abbas
Ben
B
Rampen
Sebastiaan W
SW
Massé
Guillaume
G
Allard
W Guy
WG
Belt
Simon T
ST
Robert
Jean-Michel
JM
Rowland
Steven J
SJ
Moldowan
J Michael
JM
Barbanti
Silvana M
SM
Fago
Frederick J
FJ
Denisevich
Peter
P
Dahl
Jeremy
J
Trindade
Luiz A F
LA
Schouten
Stefan
S
D000475:Alkenes / Q000032:analysis* / Q000378:metabolism; D005075:Biological Evolution; D004275:DNA, Ribosomal / Q000235:genetics; D017377:Diatoms / Q000145:classification / Q000235:genetics / Q000378:metabolism; D005580:Fossils; D019015:Geologic Sediments; D008055:Lipids / Q000096:biosynthesis; D008969:Molecular Sequence Data; D010578:Petroleum; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D013729:Terpenes / Q000032:analysis* / Q000378:metabolism
D000475:Alkenes; D004275:DNA, Ribosomal; D008055:Lipids; D010578:Petroleum; D012337:RNA, Ribosomal, 18S; D013729:Terpenes