Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Diversity of Protists II

Diversity of Protists II

Alveolates are a group of organisms recognized by the presence of alveoli, which are cytoplasmic sacs located beneath the cell membrane. While their function remains uncertain, alveoli may help regulate water balance by controlling how much water enters and leaves the cell. In dinoflagellates, these structures may serve as armor plates. There are three major types of alveolates: ciliates, which move using cilia; dinoflagellates, which use flagella for movement; and apicomplexans, which are...

Diversity of Protists III

Diversity of Protists III

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,...

Formation of Species

Formation of Species

Speciation describes the formation of one or more new species from one or sometimes multiple original species. The resulting species are discrete from the parent species, and barriers to reproduction will typically exist. There are two primary mechanisms, speciation with and without geographic isolation—allopatric and sympatric speciation, respectively.Allopatric SpeciationIn allopatric speciation, gene flow between two populations of the same species is prevented by a geographic barrier, like...

Convergent Evolution

Convergent Evolution

Evolution shapes the features of organisms over time, ensuring that they are suited for the environments in which they live. Sometimes, selection pressure leads to the rise of similar but unrelated adaptations in organisms with no recent common ancestors, a process known as convergent evolution.The structures that arise from convergent evolution are called analogous structures. They are similar in function even if they are dissimilar in structure. Further, structures can be analogous while also...

Diversity of Protists IV

Diversity of Protists IV

Amoebozoa represent a diverse group of terrestrial and aquatic protists that utilize lobe-shaped pseudopodia for locomotion and feeding. This characteristic differentiates them from the Rhizaria, which possess threadlike pseudopodia. The primary classifications within Amoebozoa include gymnamoebas, entamoebas, and the plasmodial and cellular slime molds. Phylogenetic evidence indicates that Amoebozoa diverged from a lineage that ultimately gave rise to fungi and animals.Gymnamoebas and...

Red Algae

Red Algae

Red algae, also known as rhodophytes, are primarily found in marine environments, though some species inhabit freshwater and terrestrial ecosystems. These organisms exist in both unicellular and multicellular forms, with some multicellular varieties reaching macroscopic sizes.As phototrophic organisms, red algae contain chlorophyll a; however, their chloroplasts lack chlorophyll b. Instead, they possess phycobiliproteins, which serve as major light-harvesting pigments, similar to those found in...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

The Second International Symposium on Women in Tunicate Biology.

Genesis (New York, N.Y. : 2000)·2025

Same author

Depuration of a solitary ascidian depletes transient bacteria without altering microbiome alpha-diversity.

FEMS microbiology ecology·2025

Same author

Women in tunicate research: Pioneers of the past and their present legacy.

Genesis (New York, N.Y. : 2000)·2023

Same author

1st International Symposium on Women in Tunicate Biology: Meeting report.

Genesis (New York, N.Y. : 2000)·2023

Same author

Gretchen Lambert: taxonomist, explorer, and historian of the ascidian community. Active: 1968-present.

Genesis (New York, N.Y. : 2000)·2023

Same author

Ascidian evolution and ecology.

Genesis (New York, N.Y. : 2000)·2023

Search research articles

Related Experiment Video

Updated: Jun 13, 2026

Embryo Microinjection and Electroporation in the Chordate Ciona intestinalis

Embryo Microinjection and Electroporation in the Chordate Ciona intestinalis

Published on: October 16, 2016

Polymorphism and divergence within the ascidian genus Ciona.

Marie L Nydam¹, Richard G Harrison

¹Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA. mln32@cornell.edu

Molecular Phylogenetics and Evolution

|April 21, 2010

Summary

Gene genealogies reveal distinct evolutionary relationships within the Ciona genus, identifying well-supported monophyletic groups for Ciona intestinalis Types A and B. This study clarifies ascidian evolutionary history and genetic diversity.

More Related Videos

Genotyping of Sea Anemone during Early Development

Genotyping of Sea Anemone during Early Development

Published on: May 13, 2019

In Situ Hybridization Techniques for Paraffin-Embedded Adult Coral Samples

In Situ Hybridization Techniques for Paraffin-Embedded Adult Coral Samples

Published on: August 31, 2018

Related Experiment Videos

Last Updated: Jun 13, 2026

Embryo Microinjection and Electroporation in the Chordate Ciona intestinalis

Embryo Microinjection and Electroporation in the Chordate Ciona intestinalis

Published on: October 16, 2016

Genotyping of Sea Anemone during Early Development

Genotyping of Sea Anemone during Early Development

Published on: May 13, 2019

In Situ Hybridization Techniques for Paraffin-Embedded Adult Coral Samples

In Situ Hybridization Techniques for Paraffin-Embedded Adult Coral Samples

Published on: August 31, 2018

Area of Science:

Marine Biology
Evolutionary Biology
Genetics

Background:

The genus Ciona, a model organism in developmental biology, is also noted for high heterozygosity, prompting evolutionary interest.
Previous research identified Ciona savignyi as an outgroup and Ciona intestinalis as having two forms (Types A and B).
Genealogical relationships within Ciona have been underexplored despite the genus's significance.

Purpose of the Study:

To investigate the genealogical relationships among Ciona species and forms.
To estimate levels of genetic polymorphism in natural Ciona populations.
To clarify the evolutionary divergence between Ciona intestinalis Types A and B and their relationship with other Ciona species.

Main Methods:

Phylogenetic analysis using gene genealogies of six nuclear gene loci.
Comparison of genetic divergence between Ciona intestinalis Types A and B.
Examination of the placement of Ciona roulei and a new Ciona species within the established genealogies.

Main Results:

Gene genealogies strongly support Ciona intestinalis Types A and B as distinct monophyletic groups.
Genetic divergence between Ciona intestinalis Types A and B ranges from 0.035 to 0.124.
Ciona roulei and a new Ciona species are nested within Type B lineages, separate from Type A.

Conclusions:

The study provides robust evidence for the distinct evolutionary trajectories of Ciona intestinalis Types A and B.
Morphological similarity masks significant genetic divergence between these ascidian forms.
The findings contribute to understanding ascidian evolutionary history and the genetic architecture of natural populations.