Molecular phylogeny of the animal kingdom.

  title={Molecular phylogeny of the animal kingdom.},
  author={K G Field and Gary J. Olsen and David J. W. Lane and Stephen J. Giovannoni and Michael T. Ghiselin and Elizabeth C. Raff and Norman R. Pace and Rudolf A. Raff},
  volume={239 4841 Pt 1},
A rapid sequencing method for ribosomal RNA was applied to the resolution of evolutionary relationships among Metazoa. Representatives of 22 classes in 10 animal phyla were used to infer phylogenetic relationships, based on evolutionary distances determined from pairwise comparisons of the 18S ribosomal RNA sequences. The classical Eumetazoa are divided into two groups. Cnidarians arose from a protist ancestry different from the second group, the Bilateria. Within the Bilateria, an early split… 

Monophyletic origins of the metazoa: an evolutionary link with fungi

A phylogenetic framework inferred from comparisons of small subunit ribosomal RNA sequences describes the evolutionary origin and early branching patterns of the kingdom Animalia and shows the animal lineage is monophyletic and includes choanoflagellates.

Molecular phylogeny inferred from sequences of small subunit ribosomal DNA, supports the monophyly of the metazoa.

Almost the complete sequences of small subunit (18S-like) rDNA for two poriferans and a ctenophore are determined and supported the monophyly of the metazoa.

Evolution of the Multicellular Animals

The arthropods are members of a deep primary clade within the protostomes and are not the sister taxa of either the annelids or the mollusks and the platyhelminthes are contained within the lophotrochozoan superclade.

Origin of the Mesozoa inferred from 18S rRNA gene sequences.

The sequence analysis shows that the Mesozoa branch early in the animal evolution, closely to nematodes and myxozoans, suggests probably separate origins of rhombozoids and orthonectids, suggesting that their placement in the same phylum needs to be revised.

Molecular phylogeny of metazoa (animals): Monophyletic origin

A monophyletic origin for all animals is suggested after having analyzed genes typical for multicellularity (adhesion molecules/receptors and a nuclear receptor) and presenting evidence that Porifera should be placed in the kingdom Animalia.

A molecular analysis of the phylogenetic affinities of Saccoglossus cambrensis Brambell & Cole (Hemichordata).

A polymerase chain reaction-based strategy is used to amplify, clone and sequence parts of the genes coding for 18S ribosomal RNA from Saccoglossus cambrensis, Arbacia sp.


18S ribosomal RNA sequences from 11 echinoderms are analysed using parsimony to investigate phylogenetic relationships and compared with well‐established morphological phylogenies to discover at what evolutionary distance the two approaches start to produce incongruent results.

Deducing the pattern of arthropod phytogeny from mitochondrial DNA rearrangements

THE origins of arthropods and the phylogenetic relationships among their three major living groups (atelocerates, crustaceans and chelicerates) are vigorously contended. To help resolve this, we

Metazoan phylogeny and the Cambrian radiation.

  • D. Erwin
  • Biology
    Trends in ecology & evolution
  • 1991



Evolutionary diversity of eukaryotic small-subunit rRNA genes.

The small-subunit rRNA gene sequences of the flagellated protists Euglena gracilis and Trypanosoma brucei were determined and compared and the genetic diversity in this collection of eukaryotes is seen to exceed that displayed within either the eubacterial or the archaebacterial lines of descent.

A molecular‐clock date for the origin of the animal phyla

It can be shown that the α and β haemoglobins have been evolving at a statistically equal rate since they first appeared some 450–500 million years ago, and the percentage sequence differences between several invertebrate and some vertebrate globins can be used to indicate that the initial radiation of the animal phyla occurred at least 900–1000 millions years ago.

Rapid determination of 16S ribosomal RNA sequences for phylogenetic analyses.

A protocol is described for rapidly generating large blocks of 16S rRNA sequence data without isolation of the 16 S rRNA or cloning of its gene, and its phylogenetic usefulness is evaluated by examination of several 17S rRNAs whose gene sequences are known.

Respiratory Mechanisms and the Metazoan Fossil Record

It is suggested that the Ediacara animals may be significant as a stage in the evolution of small, soft-bodied animals to larger forms with the gradual acquisition of fossilizable exo-skeletons or shells.

The structure of the yeast ribosomal RNA genes. I. The complete nucleotide sequence of the 18S ribosomal RNA gene from Saccharomyces cerevisiae.

Comparison of the yeast 18 S rRNA sequences with partial sequence data, available for rRNAs of the other eucaryotes, provides strong evidence that a substantial portion of the 18 S RNA sequence has been conserved in evolution.

The nucleotide sequences of 5S rRNAs from a sea-cucumber, a starfish and a sea-urchin.

The nucleotide sequences of 5S rRNA from three echinoderms, a sea-cucumber Stichopus oshimae, a starfish Asterina pectinifera and a sea-urchin Hemicentrotus pulcherrimus have been determined. These

Molecules as documents of evolutionary history.

Nucleotide sequence of Xenopus laevis 18S ribosomal RNA inferred from gene sequence

Comparison with the yeast (Saccharomyces cerevisiae) 18S sequence reveals extensive regions of high homology interspersed with tracts having little or no homology.

Rates of DNA sequence evolution differ between taxonomic groups.

Examination of available measurements shows that rates of DNA change of different phylogenetic groups differ by a factor of 5, with the slowest rates observed for higher primates and some bird lineages, while faster rates are seen in rodents, sea urchins, and drosophila.

Trilobites and the Origin of Arthropods

  • John L. Cisne
  • Biology
  • 1974
The appearance of fossilizable hard parts in arthropods resulted from shift in supporting function from the body cavity, primitively a hydrostatic skeleton, to the cuticle, which came to be strengthened in becoming an exoskeleton.