Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

The Fossil Record02:56

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...
What is Evolutionary History?02:35

What is Evolutionary History?

Scientists record evolutionary history by analyzing fossil, morphological, and genetic data. The fossil record documents the history of life on Earth and provides evidence for evolution. However, both fossil and living organisms offer evidence that outlines Earth’s evolutionary history.Phylogenetic trees illustrate the evolutionary relationships among these organisms. Scientists infer organisms’ common ancestry by evaluating shared morphological and genetic characteristics. Together, the fossil...
Threats to Biodiversity01:50

Threats to Biodiversity

There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species that adapted to the new conditions. In the current geological epoch, the Holocene, there is a sixth extinction event in progress. This mass extinction has been attributed to human activities and is thus provisionally called the Anthropocene. In 2019 the human population reached 7.7 billion people and is projected to comprise 10 billion by...
The Colonization of Land02:22

The Colonization of Land

Changes in the environment of the early Earth drove the evolution of organisms. As prokaryotic organisms in the oceans began to photosynthesize, they produced oxygen. Eventually, oxygen saturated the oceans and entered the air, resulting in an increase in atmospheric oxygen concentration, known as the oxygen revolution approximately 2.3 billion years ago. Therefore, organisms that could use oxygen for cellular respiration had an advantage. More than 1.5 years ago, eukaryotic cells and...
The Evidence for Evolution02:55

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.
Global Climate Change01:50

Global Climate Change

Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.

You might also read

Related Articles

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

Sort by
Same author

Phase transitions in the classical simulability of open quantum systems.

Scientific reports·2023
Same author

Patient Preparation and Radiation Protection Guidance for Adult Patients Undergoing Radioiodine Treatment for Thyroid Cancer in the UK.

Clinical oncology (Royal College of Radiologists (Great Britain))·2022
Same author

The Lyapunov spectra of quantum thermalisation.

Nature communications·2019
Same author

Day-case Treatment with Radioactive I-131 for Thyroid Cancer.

Clinical oncology (Royal College of Radiologists (Great Britain))·2017
Same author

Treatment and management of challenging behaviours in congregate and noncongregate community-based supported accommodation.

Journal of intellectual disability research : JIDR·2005
Same author

Formal and informal care for people with dementia: factors associated with service receipt.

Aging & mental health·2002

Related Experiment Video

Updated: Jul 12, 2026

Using Archival Japanese Paper and Thermoplastic Resins to Prepare Fossils for Storage, Display, Transport, and Radiography
07:30

Using Archival Japanese Paper and Thermoplastic Resins to Prepare Fossils for Storage, Display, Transport, and Radiography

Published on: November 14, 2025

End-cretaceous mass extinction event: argument for terrestrial causation.

A Hallam

    Science (New York, N.Y.)
    |November 27, 1987
    PubMed
    Summary

    The end-Cretaceous mass extinctions were selective and not instantaneous. Evidence suggests Earth-based mantle disturbances are more plausible than extraterrestrial impacts for these extinction events.

    Area of Science:

    • Paleontology
    • Geology
    • Earth Science

    Background:

    • The end-Cretaceous period experienced significant mass extinctions.
    • The Alvarez hypothesis proposed a single asteroid impact as the cause.
    • This hypothesis is challenged by the selective and non-instantaneous nature of the extinctions.

    Purpose of the Study:

    • To evaluate the plausibility of the original Alvarez hypothesis.
    • To investigate alternative models for the end-Cretaceous mass extinctions.
    • To determine the geological and environmental triggers for these extinction events.

    Main Methods:

    • Analysis of physical and chemical evidence from the stratigraphic record.
    • Comparison of extraterrestrial impact models (asteroid, comet shower) with terrestrial models.

    More Related Videos

    Reconstructing Terrestrial Paleoclimate and Paleoecology with Fossil Leaves Using Digital Leaf Physiognomy and Leaf Mass Per Area
    10:14

    Reconstructing Terrestrial Paleoclimate and Paleoecology with Fossil Leaves Using Digital Leaf Physiognomy and Leaf Mass Per Area

    Published on: October 25, 2024

    Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter
    10:20

    Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter

    Published on: March 12, 2013

    Related Experiment Videos

    Last Updated: Jul 12, 2026

    Using Archival Japanese Paper and Thermoplastic Resins to Prepare Fossils for Storage, Display, Transport, and Radiography
    07:30

    Using Archival Japanese Paper and Thermoplastic Resins to Prepare Fossils for Storage, Display, Transport, and Radiography

    Published on: November 14, 2025

    Reconstructing Terrestrial Paleoclimate and Paleoecology with Fossil Leaves Using Digital Leaf Physiognomy and Leaf Mass Per Area
    10:14

    Reconstructing Terrestrial Paleoclimate and Paleoecology with Fossil Leaves Using Digital Leaf Physiognomy and Leaf Mass Per Area

    Published on: October 25, 2024

    Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter
    10:20

    Linking Predation Risk, Herbivore Physiological Stress and Microbial Decomposition of Plant Litter

    Published on: March 12, 2013

  • Assessment of the timing and selectivity of extinction events.

    • Main Results:

    • The end-Cretaceous mass extinctions were neither geologically instantaneous nor uniformly affecting all life.
    • A single asteroid impact scenario is inconsistent with the observed extinction patterns.
    • A modified extraterrestrial model involving a comet shower is less likely than an internally driven terrestrial event.

    Conclusions:

    • The original Alvarez hypothesis requires significant modification or rejection.
    • Terrestrial causes, specifically mantle disturbances, offer a more plausible explanation for the observed extinction patterns.
    • Further research into Earth's geological processes is crucial for understanding past mass extinctions.