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

Eukaryotic Evolution

Eukaryotic Evolution

The endosymbiont theory is the most widely accepted theory of eukaryotic evolution; however, its progression is still somewhat debated. According to the nucleus-first hypothesis, the ancestral prokaryote first evolved a membrane to enclose DNA and form the nucleus. Conversely, the mitochondria-first hypothesis suggests that the nucleus was formed after endosymbiosis of mitochondria.
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...

The Evidence for Evolution

The Evidence for Evolution

Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.The collection of fossils within sedimentary rocks give a record of common ancestry and often depicts the history of evolution.

Phylogeny

Phylogeny

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...

The Tree of Life - Bacteria, Archaea, Eukaryotes

The Tree of Life - Bacteria, Archaea, Eukaryotes

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 extant and...

Phylogenetic Trees

Phylogenetic Trees

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.The length of the branches can depict time or the relative amount of change among organisms. For instance, the branch length might indicate the number of amino acid changes in the sequence that underlies the...

Phylogenetic Trees

Phylogenetic Trees

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.The length of the branches can depict time or the relative amount of change among organisms. For instance, the branch length might indicate the number of amino acid changes in the sequence that underlies the...

You might also read

Related Articles

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

Sort by

Same author

Molecular characterization of nervous system organization in the hemichordate acorn worm Saccoglossus kowalevskii.

PLoS biology·2023

Same author

Arthur B. Pardee (1921-2019).

Science (New York, N.Y.)·2019

Same author

Untangling posterior growth and segmentation by analyzing mechanisms of axis elongation in hemichordates.

Proceedings of the National Academy of Sciences of the United States of America·2019

Same author

Correction: Dorsoventral Patterning in Hemichordates: Insights into Early Chordate Evolution.

PLoS biology·2015

Same author

Hemichordate genomes and deuterostome origins.

Nature·2015

Same author

The deuterostome context of chordate origins.

Nature·2015

Search research articles

Related Experiment Video

Updated: Jun 8, 2026

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms

Published on: May 25, 2018

Enzymes, embryos, and ancestors.

¹Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3200, USA. jgerhart@berkeley.edu

Annual Review of Cell and Developmental Biology

|October 9, 2010

Summary

This research explores cellular regulation and early development, revealing allosteric enzyme mechanisms and key processes in vertebrate axis formation using Xenopus laevis. Comparative studies highlight conserved developmental pathways in chordates and hemichordates.

Area of Science:

Biochemistry and Molecular Biology
Developmental Biology and Evolutionary Biology

Background:

Investigated feedback inhibition in pyrimidine biosynthesis, identifying an allosteric enzyme with distinct regulatory and substrate-binding sites.
Studied early axis formation in Xenopus laevis, characterizing cortical rotation and its role in Spemann's organizer development.

Discussion:

Dissociation of the pyrimidine biosynthesis enzyme into subunits provided early evidence for allosteric regulation.
Perturbation of cortical rotation in Xenopus embryos demonstrated its critical role in establishing embryonic axes and phenotypes.

Key Insights:

The pyrimidine biosynthesis enzyme serves as a foundational model for understanding allosteric regulation.
Xenopus laevis development elucidated conserved mechanisms of vertebrate axis formation, including cortical rotation.

More Related Videos

Protocols for Obtaining Zygotic and Somatic Embryos for Studying the Regulation of Early Embryo Development in the Model Legume Medicago truncatula

Protocols for Obtaining Zygotic and Somatic Embryos for Studying the Regulation of Early Embryo Development in the Model Legume Medicago truncatula

Published on: June 9, 2015

Dissection and Downstream Analysis of Zebra Finch Embryos at Early Stages of Development

Dissection and Downstream Analysis of Zebra Finch Embryos at Early Stages of Development

Published on: June 21, 2014

Related Experiment Videos

Last Updated: Jun 8, 2026

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms

Enhanced Genome Editing with Cas9 Ribonucleoprotein in Diverse Cells and Organisms

Published on: May 25, 2018

Protocols for Obtaining Zygotic and Somatic Embryos for Studying the Regulation of Early Embryo Development in the Model Legume Medicago truncatula

Protocols for Obtaining Zygotic and Somatic Embryos for Studying the Regulation of Early Embryo Development in the Model Legume Medicago truncatula

Published on: June 9, 2015

Dissection and Downstream Analysis of Zebra Finch Embryos at Early Stages of Development

Dissection and Downstream Analysis of Zebra Finch Embryos at Early Stages of Development

Published on: June 21, 2014

Comparative analysis of hemichordate and chordate development suggests ancient, shared axis-formation pathways predating the Cambrian period.

Outlook:

Further molecular elucidation of Xenopus axis formation has validated early observations.
Understanding conserved developmental pathways offers insights into the evolution of early life forms.