Abstract
In spite of the rich fossil record and multiple descriptions of morphological and embryological characteristics, the origin and subsequent evolution of echinoderms remain highly controversial issues. Using sequence data derived from 18S rDNA, we have investigated the phylogenetic relationships among five extant classes of echinoderms—namely, crinoids, asteroids, ophiuroids, echinoids, and holothurians. Almost complete sequences of 18S rDNA were determined for one species in each class, and phylogenetic trees were constructed both by the neighbor joining method and by the maximum-likelihood method, with a hemichordate as an outgroup. The trees constructed by these methods support the hypothesis that the phylum Echinodermata can be subdivided into two subphyla, Pelmatozoa and Eleutherozoa. The class Holothuroidea, which has been the subject of debate with respect to whether the members are primitive or advanced echinoderms, did not occupy a primitive position but had an affinity for the class Echinoidea. Since both trees gave different branching topologies for the order of emergence of asteroids and ophiuroids, it seems likely that these two groups emerged within a very short period of time. A rough estimate of the timing of the divergence of the five classes from the present molecular analysis coincided with that deduced from the fossil record.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Baker AN, Rowe FWE, Clark HES (1986) A new class of Echinodermata from New Zealand. Nature 321:862–864
Barnes RD (1987) Invertebrate zoology, 5th ed. Saunders College Publishing, Fort Worth
Brusca RC, Brusca GJ (1990) Invertebrates. Sinauer Associates, Sunderland, MA
Davidson EH (1986) Gene activity in early development, 3rd ed. Academic Press, New York
Felsenstein J (1981) Evolutionary trees from DNA sequences: a maximum likelihood approach. J Mol Evol 17:368–376
Felsenstein J (1985) Confidence limits on phylogenies: an approach using the bootstrap. Evolution 39:783–791
Felsenstein J (1991) PHYLIP manual version 3.4.1. University of Washington, Seattle
Field KG, Ghislen MT, Lane DJ, Olsen GJ, Pace NR, Raff EC, Raff RA (1988) Molecular phylogeny of the animal kingdom. Science 239:748–753
Hasegawa M, Kishino H, Saitou N (1991) On the maximum likelihood method in molecular phylogenetics. J Mol Evol 32: 443–445
Higuchi RG, Ochman H (1989) Producing of single-stranded DNA templates by exonuclease digestion following the polymerase chain reaction. Nucleic Acids Res 17:5865
Holland ND (1988) The meaning of developmental asymmetry for echinoderm evolution: a new interpretation. In: Paul CRC, Smith AB (eds) Echinoderm phylogeny and evolutionary biology, Clarendon Press, Oxford, pp 13–25
Jefferies RPS (1988) How to characterize the Echinodermata—some implications of the sister-group relationship between echinoderms and chordates. In: Paul CRC, Smith AB (eds) Echinoderm phylogeny and evolutionary biology. Clarendon Press, Oxford, pp 3–12
Jukes TH, Cantor CR (1969) Evolution of protein molecules. In: Murno NH (ed) Mammalian protein metabolism, vol III. Academic Press, New York, pp 21–132
Matsumura T, Shigei M (1988) Collagen biochemistry and the phylogeny of echinoderms. In: Paul CRC, Smith AB (eds) Echinoderm phylogeny and evolutionary biology, Clarendon Press, Oxford, pp 43–52
Mortensen T (1921) Studies of the development and larval forms of echinoderms. GEC Gao, Copenhagen
Pace NR, Stahl DA, Lane DJ, Olsen GJ (1985) Analyzing natural microbial populations by rRNA sequences. Am Soc Microbiol News 51:4–12
Paul CRC, Smith AB (1984) The early radiation and phylogeny of echinoderms. Biol Rev 59:443–481
Raff RA (1987) Constraint, flexibility, and phylogenetic history in the evolution of direct development in sea urchins. Dev Biol 119:6–19
Raff RA, Field KG, Ghiselin MT, Lane DJ, Olsen GJ, Pace NR, Parks AL, Parr BA, Raff EC (1988) Molecular analysis of distant phylogenetic relationships in echinoderms. In: Paul CRC, Smith AB (eds) Echinoderm phylogeny and evolutionary biology, Clarendon Press, Oxford, pp 29–41
Saitou N, Nei M (1987) The neighbor joining method: a new method for reconstructing phylogenetic trees. Mol Biol Evol 4:406–425
Sanger F, Nicklen S, Coulson AR (1977) DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci USA 74: 5463–5467
Smiley S (1986) Metamorphosis in Stichopus californicus and its phylogenetic implications. Biol Bull 171:611–631
Smiley S (1988) The phylogenetic relationships of holothurians: a cladistic analysis of the extant echinoderm classes. In: Paul CRC, Smith AB (eds) Echinoderm phylogeny and evolutionary biology, Clarendon Press, Oxford, pp 69–84
Smith AB (1984) Echinoid palaeobiology. George Allen and Unwin, London
Smith AB (1988) Fossil evidence for the relationships of extant echinoderm classes and their times of divergence. In: Paul CRC, Smith AB (eds) Echinoderm phylogeny and evolutionary biology, Clarendon Press, Oxford, pp 85–97
Strathmann RR (1988) Larvae, phylogeny, and von Baer's Law. In: Paul CRC, Smith AB (eds) Echinoderm phylogeny and evolutionary biology, Clarendon Press, Oxford, pp 53–68
Wada H, Makabe KW, Nakauchi M, Satoh N (1992) Phylogenetic relationships between solitary and colonial ascidians, as inferred from the sequence of the central region of their respective 18S rDNA. Biol Bull 183:448–455
Author information
Authors and Affiliations
Additional information
Correspondence to: H. Wada
Rights and permissions
About this article
Cite this article
Wada, H., Satoh, N. Phylogenetic relationships among extant classes of echinoderms, as inferred from sequences of 18S rDNA, coincide with relationships deduced from the fossil record. J Mol Evol 38, 41–49 (1994). https://doi.org/10.1007/BF00175494
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00175494