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.

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 Fossil Record

The Fossil Record

The fossil record documents only a small fraction of all organisms that have ever inhabited Earth. Fossilization is a rare process, and most organisms never become fossils. Moreover, the fossil record only exhibits fossils that have been discovered. Nevertheless, sedimentary rock fossils of long-lived, abundant, hard-bodied organisms dominate the fossil record. These fossils offer valuable information, such as an organism's physical form, behavior, and age. Studying the fossil record helps...

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...

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...

You might also read

Related Articles

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

Sort by

Same author

Author Correction: Basin-scale reconstruction of euxinia and Late Devonian mass extinctions.

Nature·2023

Same author

Basin-scale reconstruction of euxinia and Late Devonian mass extinctions.

Nature·2023

Same author

Breathless through Time: Oxygen and Animals across Earth's History.

The Biological bulletin·2022

Same author

The Sedimentary Geochemistry and Paleoenvironments Project.

Geobiology·2021

Search research articles

Related Experiment Video

Updated: Nov 9, 2025

A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles

A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles

Published on: July 11, 2025

Dead clades walking are a pervasive macroevolutionary pattern.

B Davis Barnes¹, Judith A Sclafani^2,3, Andrew Zaffos⁴

¹Department of Geosciences, Pennsylvania State University, University Park, PA 16802; bdavisbarnes@psu.edu.

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

|April 8, 2021

Summary

This summary is machine-generated.

Marine fossil orders experiencing diversity loss, termed dead clades walking, often persist for millions of years. This pattern significantly impacts macroevolutionary trends beyond mass extinctions.

Keywords:

biodiversity macroevolution mass extinction recovery

More Related Videos

Resurrection of Dormant Daphnia magna: Protocol and Applications

Resurrection of Dormant Daphnia magna: Protocol and Applications

Published on: January 19, 2018

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: Nov 9, 2025

A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles

A Concoction Pipeline for Generating Molecular Operational Taxonomic Units (MOTUs) Among Riparian and Aquatic Beetles

Published on: July 11, 2025

Resurrection of Dormant Daphnia magna: Protocol and Applications

Resurrection of Dormant Daphnia magna: Protocol and Applications

Published on: January 19, 2018

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:

Paleontology
Macroevolution
Biodiversity Science

Background:

The concept of "dead clades walking" (DCWs) describes fossil marine orders with reduced genus richness post-extinction.
Previous interpretations suggest DCWs highlight long-term macroevolutionary consequences of mass extinctions.

Purpose of the Study:

To analyze the duration and impact of DCWs on Phanerozoic biodiversity.
To determine if DCW patterns are exclusively linked to mass extinction events.

Main Methods:

Analysis of fossil occurrences for 134 marine invertebrate orders using the Paleobiology Database.
Application of a Bayesian method to identify significant change points in genus richness.

Main Results:

70 orders identified with major diversity loss and no recovery.
The median duration for these DCW orders exceeds 30 million years.
Many diversity drops without recovery occur during background extinction, not just mass extinctions.

Conclusions:

The "dead clades walking" phenomenon is more persistent and widespread than previously thought.
DCW patterns are a significant factor in macroevolutionary turnover, occurring during both mass and background extinction intervals.
Over half of marine invertebrate orders exhibit DCW patterns, underscoring their broad impact on biodiversity.