Read phylogeny and evolution of the mollusca, marine ecology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Molluscan evolution, whatever the underlying tree, is known to be laden with convergence at all taxon levels, including morphological features previously suspected to be informative for deep phylogeny e. Phylogeny trex tree and reticulogram reconstruction is dedicated to the reconstruction of phylogenetic trees, reticulation networks and to the inference of horizontal gene transfer hgt events. Phylogeny of the caenogastropoda mollusca, based on. The fossil record of mollusks is relatively complete, and they are well represented in most fossilbearing marine strata. Molluscan shells are usually made of calcium carbonate and are covered by an organic matrix, the periostracum. In addition, molluscan evolutionary development though itself still an embryo is. Freshwater molluscs are common animals in lakes and streams. Methods sequencing and assembly of mitogenomes information on studied species, vouchers, and sampling localities can be found in additional file 1.
Phylogeny and evolution of the mollusca request pdf. Gastropoda previously known as univalves and sometimes spelled gasteropoda are a major part of the phylum mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The phylum mollusca is the second largest group of animals and occur in virtually all habitats. Free fulltext pdf articles from hundreds of disciplines, all in one place first molecular phylogeny of the subfamily polycerinae mollusca, nudibranchia, polyceridae pdf. Spiralian phylogeny informs the evolution of microscopic. Origin and evolutionary radiation of the mollusca edited by john d. In particular, a wellresolved phylogeny for aplacophora would provide polarity for the evolution of key morphological characters such as the radula. It is also arguably the animal phylum with the largest body plan disparity. Seashell phylogeny and evolution teacher guide the seashell phylogeny and evolution activity is an interactive online activity that can be done in class or assigned as homework. The mollusca are the second largest animal phylum and boast a fossil record of over. Because aculifera is the sister taxon of all other molluscs, understanding the phylogeny of this group is critical to understanding early molluscan evolution. The number of fossil species is estimated between 60,000 and 100,000 additional species. Resolving the evolutionary relationships of molluscs.
Mollusca, phylogenomics, nudibranchs, sea slugs, rnaseq, diet correspondence. Molecular phylogeny and evolution of pulmonata mollusca. Phylogenomic methods are beginning to resolve one of the more tricky issues facing evolutionary biologists making sense of the complicated interrelationships of the mollusca. These records exclude the scaphopods and cephalopods but include the extinct merismoconchia, helcionellida, and rostroconchia. The phylogeny of mollusca is a controversial issue. This file contains additional information such as exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it.
A multigene phylogeny of cephalopoda supports convergent. Phylogeny and evolution of the mollusca book also available for read online, mobi, docx and mobile and kindle reading. Taylor department of zoology the natural history museum. It was previously argued that mollusca originated from annelids, generally assumption based on the evidence of fossilized monoplacophorans. Researchers complete mollusk evolutionary tree sciencedaily. Although there is little doubt about the monophyly of the eight extant classes, relationships between these groups are controversial. Attempts to understand the early evolution of molluscs become even more. Several graduate students in the lab focus on this group of invertebrates. The marine environment is comprised of numerous divergent organisms living under similar selective pressures, often resulting in the evolution of convergent structures such as the fusiform body shape of pelagic squids, fishes, and some marine mammals. With estimates of up to 200,000 extant species, mollusca is second in number of species only to arthropoda. Researchers have compiled the most comprehensive evolutionary tree for mollusks to date. Pdf phylogeny and evolution of the mollusca download.
Most previous studies on the phylogeny of molluscs have been driven by the conchifera concept 1, 95 and emphasised the opinion that serialia violates putative conchiferan synapomorphies 12. However, little is known about the frequency of, and circumstances leading to, convergent evolution in the open. Mollusca constitutes the second largest animal phylum and the most diverse in the marine realm. The pyramidellidae are marine ectoparasitic species with a few exceptions on a variety of hosts e. This phylum includes gastropods, bivalves, scaphopods, cephalopods, and several other groups. The paper gives an overview of the modern hypotheses on the origin of the phylum mollusca and the formation of its main classes. The phylogeny of nudibranchia opisthobranchia, gastropoda, mollusca reconstructed by three molecular markers showing 14 of 31 pages in this article. Moreover, with species as different as meiofaunal worms and giant squid, mollusca is one of the most morphologically variable metazoan phyla. A combined approach toward resolving the phylogeny of mollusca. The mollusca are the second largest animal phylum and boast a fossil record of. Contents list of contributors xi part i origin of mollusca and evolution of the major groups 1.
Phylogeny and evolution of the mollusca by winston ponder. Phylogeny and evolution of the mollusca article in bulletin of marine science miami 832. Around 85,000 extant species of molluscs are recognized. The mollusca are the second largest animal phylum and boast a fossil record stretching back over 540 million years. Mussels and clams have a hinged, bivalved shell and are generally suspension andor deposit feeders. Phylogeny and adaptive radiation the first molluscs probably arose during precambrian times because fossils attributed to mollusca have been found in geological strata as old as the early cambrian period. Both chitons and conchifers date from the earliest cambrian time about 542 million years ago. The gene order of chaetopleura proved to be unexpectedly primitive among. Phylogeny and phylogenetic relationship of phylum mollusca. This text will provide the first general account of molluscs in decades and will include hundreds of colour figures. The mollusca are the second largest animal phylum and boast a fossil record of over 540 million years.
Resolving the evolutionary relationships of molluscs with phylogenomic tools. The evolution of the molluscs is the way in which the mollusca, one of the largest groups of invertebrate animals, evolved. Resolving the evolutionary relationships of molluscs with. This document describes supporting resources that can be used to teach students about. Origin and the early evolution of the phylum mollusca. Evolutionary relationships among the eight major lineages of mollusca have remained unresolved despite their diversity and importance. Ponder and lindberg provides a breathtaking overview of the evolutionary history of the mollusca, effectively melding information from anatomy, ecology, genomics, and paleobiology to explore the depths of molluscan phylogeny. First molecular phylogeny of the subfamily polycerinae. Phylogeny and evolution of the mollusca, marine ecology. The doubtfulness of assignment of the precambrian vendian softbodied fossil kimberella to mollusks is argued. Phylogeny of molluscs world congress of malacology perth, western australia 1116 july 2004. Request an exam or desk copy recommend to your library pdf. Molluscs are a diverse animal phylum with a formidable fossil record. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext.
Recommended articles citing articles 0 references 1. Yet, their evolutionary origin has been a matter of debate for many decades haas, 1981. Spiralian phylogeny informs the evolution of microscopic lineages. Many members of this group live attached to the body surface or inside the burrows of other marine invertebrates, including crustaceans, holothurians, echinoids, cnidarians, sipunculans and echiurans. On july 11 th 2004 over 300 biologists and paleontologists from more than 40 countries gathered in perth, australia for the world congress of malacology. Electronic supplement abstract pdf file 1 and poster pdf file 10. A goal of our lab is to better understand the diversification of this animal group from phylogenetic and ecological perspectives.
Pdf phylogeny and evolution of the mollusca david r. However, although the possible evolutionary path of shell coiling can be inferred from phylogenetic studies, the mechanistic explanation of the. The proportion of undescribed species is very high. Pdf phylogeny and evolution of the mollusca martin. We analysed a comprehensive multilocus molecular data set for molluscs, the first to include multiple species from all classes, including five monoplacophorans in both extant. What characteristics do mollusks have that are not present in the previous four animal phyla.
The phylogeny of nudibranchia opisthobranchia, gastropoda. A new phylogenetic hypothesis for euthyneura is proposed based on the analysis of primary sequence data mitochondrial cox1, trnv, rrnl, trnlcun, trna, trnp, nad6, and nad5 genes and the phylogenetic utility of two rare genomic changes the relative position of the mitochondrial trnp gene, and an insertiondeletion event in a conserved region of the. In this article we will discuss about the phylogeny and phylogenetic relationship of phylum mollusca. Conclusions derived from single organ systems, or the shell alone, are not able to exclude alternative interpretations. Phylogeny and evolution of the mollusca by winston ponder, david r. From sea to land and beyond bmc evolutionary biology. The phylogenetic relationships among the major groups of pulmonata were studied by the information derived from a concatenated dataset consisting of mitochondrial 16s and coi and nuclear 18s and 28s markers. Previous investigations of molluscan phylogeny, based primarily on nuclear ribosomal gene sequences or morphological data, have been unsuccessful at elucidating these relationships. New insights into the phylogeny of the pyramidellidae. Abstract the systematics, classification and phylogeny of the caenogastropoda are revised based on an analysis of the morphology of representatives of all branches. Structure soft bodied animals name from latin word mollus meaning soft most are protected by a hard shell made of calcium carbonate have a reduced internal cell or have lost the shell completely during evolution.
Investigation of molluscan phylogeny using largesubunit and smallsubunit nuclear rrna sequences. Towards a phylogeny and evolution of acochlidia mollusca. Euthyneura as paraphyletic due to the emergence of taxa from opisthobranchia and lower heterobranchia. Its outstanding success is due to thoughtful planning, focused complementary contributions from 36 expert authors, and careful. Fasta formatted files were generated from subtrees that were produced. The hypothesized ancestral order for chitons is based on outgroup comparison and it is also the most frequent among chitons. The euthyneura are considered to be the most successful and diverse group of gastropoda.
Such features all are plesiomorphic for dorsoconchs in our topology figure 1 c. A combined approach toward resolving the phylogeny of. Phylogeny and evolution of the mollusca by winston ponder, david. Previous morphologybased phylogenetic studies have been greatly hampered by rampant parallelism in morphological characters or by incomplete taxon sampling. There are no known fossil records of caudofoveates and solenogasters. Mollusca is the secondlargest phylum of invertebrate animals after the arthropoda. The cambrian stage of molluscan evolution is characterized based on the paleontological material. Shells are the most conspicuous features of molluscs. Although many are distinguished by a hard external shell, others such. Many nonmarine molluscs are threatened with more recorded extinctions than all tetrapod vertebrates combined. Download acrobat pdf file 192kb supplementary data 1. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of. The evolution of molluscs wanninger 2019 biological.
Evidence of evolution can be found in the chromosomal analysis of snails. Trex includes several popular bioinformatics applications such as muscle, mafft, neighbor joining, ninja, bionj, phyml, raxml, random phylogenetic tree generator and. The second largest phylumj in the animal kingdom surpassed only by the arthropods, a highly diverse phylum that includes both familiar animals such as snails and slugs, periwinkles, whelks, limpets, mussels, oysters, scallops, clams, squid, octopus, cuttlefish and many other forms. Pyramidellids pierce the tissue of their hosts with a buccal stylet and suck out body. Galeommatoidea is a superfamily of bivalves that exhibits remarkably diverse lifestyles. But this theory was largely rejected because the body structure of neopilina galatheae has revealed a semisegmentation metamerism that weakens the argument that mollusc has evolved from the annelid. Pdf download phylogeny and evolution of the mollusca.
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