Related Experiment Video
Updated: Dec 24, 2025
10:23
A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles
Published on: July 11, 2025
441
Spaghetti to a Tree: A Robust Phylogeny for Terebelliformia (Annelida) Based on Transcriptomes, Molecular and
Josefin Stiller1,2, Ekin Tilic1,3, Vincent Rousset1
1Scripps Institution of Oceanography, University of California, San Diego, CA 92037, USA.
Biology
|April 10, 2020
Summary
This study reconstructs the evolutionary history of spaghetti worms (Terebelliformia) using transcriptomes and morphology. It clarifies relationships, establishes new family Melinnidae, and reveals an ancestor with both branchiae and chaetae.
Area of Science:
- Marine Biology
- Evolutionary Biology
- Phylogenetics
- Annelid Taxonomy
Background:
- Terebelliformia (spaghetti worms) are diverse marine annelids with unclear evolutionary relationships.
- Previous studies lacked robust phylogenetic frameworks, hindering understanding of their morphological and ecological diversity.
Purpose of the Study:
- To establish a robust phylogeny for Terebelliformia using transcriptomic and morphological data.
- To clarify the evolutionary history and relationships of major terebelliform lineages.
- To investigate the evolution of key morphological traits, such as branchiae and chaetae.
Main Methods:
- Phylogenetic analysis of 20 terebelliforms and an outgroup using 12,674 orthologous genes from transcriptomes.
- Supplemented backbone phylogeny with 121 species using five genes and 90 morphological characters for fine-scale relationships.
- Reconstruction of morphological character evolution on the phylogenetic tree.
Main Results:
- Established monophyly for six major terebelliform taxa: Pectinariidae, Ampharetinae, Alvinellidae, Trichobranchidae, Terebellidae, and Melinninae.
- Redefined Ampharetidae to include Ampharetinae, Amaginae, and Amphicteinae, and established Melinnidae as sister to Terebellidae.
- Resolved taxonomic issues, synonymizing Telothelepodidae and proposing new subtribes within Terebellinae, and identified paraphyletic genera and undescribed species.
Conclusions:
- The study provides a robust phylogenetic framework for Terebelliformia, clarifying evolutionary relationships and taxonomic classifications.
- Morphological analyses support an ancestral terebelliform possessing both branchiae and chaetae, challenging previous hypotheses.
- This integrated phylogenetic approach offers insights into the evolution of annelid diversity and trait evolution.
Related Concept Videos
02:54Evolutionary Relationships through Genome Comparisons
6.8K
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
6.8K
01:23Phylogeny
56.5K
Phylogeny is concerned with the evolutionary diversification of organisms or groups of organisms. A group of organisms with a name is called a taxon (singular). Taxa (plural) can span different levels of the evolutionary hierarchy. For instance, the group containing all birds is a taxon (comprising the class Aves), and the group of all species of daisies (the genus Bellis) is a taxon. Phylogenies can likewise include just one genus (i.e., depict species relationships) or span an entire kingdom.
56.5K
03:21Phylogenetic Trees
49.1K
Phylogenetic trees come in many forms. It matters in which sequence the organisms are arranged from the bottom to the top of the tree, but the branches can rotate at their nodes without altering the information. The lines connecting individual nodes can be straight, angled, or even curved.
49.1K
02:40The Tree of Life - Bacteria, Archaea, Eukaryotes
37.3K
The “tree of life” describes the evolution of life and the evolutionary relationships between organisms. The root of the tree is the common ancestor to all life on Earth. All other species radiate from this point, much like the branches of a tree. The numerous tips of these branches on the tree of life represent every living, or extant, species. Extinct species, which are species that no longer exist, can be found towards the center of the tree. Currently, these organisms, both...
37.3K
01:29Modern Molecular Taxonomy
497
Advancements in molecular biology have revolutionized the identification and characterization of bacteria, with multiple methods leveraging DNA sequencing for enhanced precision. As sequencing technologies improve and costs decline, these approaches are increasingly used in clinical, environmental, and evolutionary studies.Multilocus Sequence Typing (MLST) examines several housekeeping genes, essential chromosomal genes encoding cellular functions, to distinguish strains. Approximately...
497
01:27Diversity of Protists III
649
Rhizaria are a diverse group of unicellular protists characterized by their threadlike cytoplasmic extensions known as pseudopodia. These structures aid in both locomotion and feeding, giving Rhizaria an amoeboid appearance. Their amoeboid morphology once led to taxonomic confusion, but molecular phylogenetics has clarified their evolutionary placement and emphasized their shared use of pseudopodia despite divergent lineages.This clade comprises diverse lineages such as Chlorarachniophyta,...
649