Natural Science 301 Guidelines

This is an open forum area for all members for discussions on all issues of science and origins. This area will and does get volatile at times, but we ask that it be kept to a dull roar, and moderators will intervene to keep the peace if necessary. This means obvious trolling and flaming that becomes a problem will be dealt with, and you might find yourself in the doghouse.

As usual, Tweb rules apply. If you haven't read them now would be a good time.

Forum Rules: Here
See more
See less

New evidence changes the mass extinction between the Edicarian and the PreCambrian.

  • Filter
  • Time
  • Show
Clear All
new posts

  • New evidence changes the mass extinction between the Edicarian and the PreCambrian.

    There may a new way of looking at the mass extinction at the end of the Edicarian than scientists believe in the past. Competitive replacement by complex communities developed in the late Edicarian may be an important factor. The transformation may by somewhat more gradual than previously thought.


    First Animals Formed Complex Ecological Communities Before the Cambrian Explosion

    By PLOS MAY 29, 2022

    A group of Ediacaran specimens of Fractofusus and Plumeropriscum from the “E” surface, Mistaken Point Ecological Reserve, Newfoundland, Canada. Credit: Charlotte G. Kenchington (CC BY 4.0)

    Metacommunity analysis suggests succession, not mass extinction, explains the Ediacaran diversity drop.

    Early animals developed complex ecological communities more than 550 million years ago, setting the evolutionary stage for the Cambrian explosion, according to a research study by Rebecca Eden, Emily Mitchell, and colleagues at the University of Cambridge, UK, published on May 17th in the open-access journal PLOS Biology.

    The first animals evolved around 580 million years ago, towards the end of the Ediacaran period. However, the fossil record indicates that after an initial boom, diversity declined in the run-up to the dramatic burgeoning of biodiversity in the so-called “Cambrian explosion” nearly 40 million years later. Scientists have suggested this drop in diversity is evidence of a mass extinction event roughly 550 million years ago – possibly caused by an environmental catastrophe – but previous research has not looked into the structure of these ancient ecological communities.

    To evaluate the evidence for an Ediacaran mass extinction, scientists analyzed the metacommunity structure of three fossil assemblages that span the last 32 million years of this geological period (between 575 to 543 million years ago). They used published paleoenvironmental data, such as ocean depth and rock characteristics, to look for metacommunity structure indicative of environmental specialization and interactions between species. The analysis revealed increasingly complex community structures in the later fossil assemblages, suggesting that species were becoming more specialized and engaging in more inter-species interactions towards the end of the Ediacaran era, a trend often seen during ecological succession.

    According to the authors, the results point to competitive exclusion, rather than mass extinction, as the cause of the diversity drop in the late Ediacaran period. The analysis indicates that the features of ecological and evolutionary dynamics commonly associated with the Cambrian explosion — such as specialization and niche contraction — were established by the first animal communities in the late Ediacaran.

    Mitchell adds, “We found that the factors behind that explosion, namely community complexity and niche adaptation, actually started during the Ediacaran, much earlier than previously thought. The Ediacaran was the fuse that lit the Cambrian explosion.”

    © Copyright Original Source

    Glendower: I can call spirits from the vasty deep.
    Hotspur: Why, so can I, or so can any man;
    But will they come when you do call for them? Shakespeare’s Henry IV, Part 1, Act III:

    go with the flow the river knows . . .


    I do not know, therefore everything is in pencil.

Related Threads


Topics Statistics Last Post
Started by NorrinRadd, 08-11-2022, 04:15 AM
1 response
Last Post TheLurch  
Started by TheLurch, 08-10-2022, 08:05 PM
6 responses
Last Post TheLurch  
Started by shunyadragon, 08-01-2022, 09:59 AM
1 response
Last Post rogue06
by rogue06
Started by Cow Poke, 07-28-2022, 08:09 AM
18 responses
Last Post Sparko
by Sparko
Started by Hypatia_Alexandria, 07-27-2022, 10:28 AM
64 responses
Last Post Sparko
by Sparko