Profile image
By Alton Parrish (Reporter)
Contributor profile | More stories
Story Views
Now:
Last Hour:
Last 24 Hours:
Total:

Early Species Developed Much Faster Than Previously Thought

% of readers think this story is Fact. Add your two cents.


When Earth’s species were rapidly diversifying nearly 500 million years ago, that evolution was driven by complex factors including global cooling, more oxygen in the atmosphere, and more nutrients in the oceans. But it took a combination of many global environmental and tectonic changes occurring simultaneously and combining like building blocks to produce rapid diversification into new species, according to a new study by Dr. Alycia Stigall, Professor of Geological Sciences at Ohio University.

She and fellow researchers have narrowed in a specific time during an era known as the Ordovician Radiation, showing that new species actually developed rapidly during a much shorter time frame than previously thought. The Great Biodiversification Event where many new species developed, they argue, happened during the Darriwilian Stage about 465 million years ago. Their research, “Coordinated biotic and abiotic change during the Great Ordovician Biodiversification Event: Darriwilian assembly of early Paleozoic building blocks,” was published in Palaeogeography, Palaeoclimatology, Palaeoecology as part of a special issue they are editing on the Great Ordovician Biodiversification Event.

Building block model of the earth system that produced the Great Ordovician Biodiversificaiton Event. 

Building block model of the earth system that produced the Great Ordovician Biodiversificaiton Event. Figure from Stigall et al., 2019.
Figure from Stigall et al., 2019.
New datasets have allowed them to show that what previously looked like species development widespread over time and geography was actually a diversification pulse. Picture a world before the continents as we know them, when most of the land mass was south of the equator, with only small continents and islands in the vast oceans above the tropics. Then picture ice caps forming over the southern pole. As the ice caps form, the ocean recedes and local, isolated environments form around islands and in seas perched atop continents. In those shallow marine environments, new species develop.

Then picture the ice caps melting and the oceans rising again, with those new species riding the waves of global diversification to populate new regions. The cycle then repeats producing waves of new species and new dispersals.

Lighting the Spark of Diversification

The early evolution of animal life on Earth is a complex and fascinating subject. The Cambrian Explosion (between about 540 to 510 million years ago) produced a stunning array of body plans, but very few separate species of each, notes Stigall. But nearly 40 million years later, during the Ordovician Period, this situation changed, with a rapid radiation of species and genera during the Great Ordovician Biodiversification Event.

The triggers of the GOBE and processes that promoted diversification have been subject to much debate, but most geoscientists haven’t fully considered how changes like global cooling or increased oxygenation would foster increased diversification.

A recent review paper by Stigall and an international team of collaborators attempts to provide clarity on these issues. For this study, Stigall teamed up with Cole Edwards (Appalachian State University), a sedimentary geochemist, and fellow paleontologists Christian Mac Ørum Rasmussen (University of Copenhagen) and Rebecca Freeman (University of Kentucky) to analyze how changes to the physical earth system during the Ordovician could have promoted this rapid increase in diversity.

In their paper, Stigall and colleagues demonstrate that the main pulse of diversification during the GOBE is temporally restricted and occurred in the Middle Ordovician Darriwilian Stage (about 465 million years ago). Many changes to the physical earth system, including oceanic cooling, increased nutrient availability, and increased atmospheric oxygen accumulate in the interval leading up to the Darriwilian.

These physical changes were necessary building blocks, but on their own were not enough to light the spark of diversification.

The missing ingredient was a method to alternately connect and isolate populations of species through cycles of vicariance and dispersal. That spark finally occurs in the Darriwilian Stage when ice caps form over the south pole of the Ordovician Earth. The waxing and waning of these ice sheets caused sea level to rise and fall (similar to the Pleistocene), which provided the alternate connection and disconnection needed to facilitate rapid diversity accumulation.

Stigall and her collaborators compared this to the assembly of building blocks required to pass a threshold.

Contacts and sources:
Ohio University

Citation: Coordinated biotic and abiotic change during the Great Ordovician Biodiversification Event: Darriwilian assembly of early Paleozoic building blocks
 Alycia L.StigallCole T. Edwards, Rebecca L.FreemanChristian M.Ø.Rasmussen   Palaeogeography, Palaeoclimatology, Palaeoecology Volume 530, 15 September 2019, Pages 249-270 https://www.sciencedirect.com/science/article/pii/S0031018219302305?via%3Dihub



Source: http://www.ineffableisland.com/2019/08/early-species-developed-much-faster.html

Support BeforeitsNews by trying our natural health products! Join our affiliate program
Order by Phone at 888-809-8385 or online at www.mitocopper.com


Get our Free Ebook, "Suppressed Health Secrets"  with  Natural Cures THEY don't want you to know!

APeX - Far superior to colloidal silver!  Destroys Viruses, Bacteria, Pathogens with Oxygen plus Silver!Supreme Fulvic - Nature's most important supplement! Vivid Dreams again!
Ultimate Curcumin - Natural pain relief, reduce inflammation and so much more.
MitoCopper - Bioavailable Copper destroys pathogens and gives you more energy. (See Blood Video)
Oxy Powder - Natural Colon Cleanser!  Cleans out toxic buildup with oxygen!  
Organic Hemp Extract (CBD) - Full Spectrum high CBD (3300mg) hemp extract eases stiff joints, relieves stress and more!
Nascent Iodine - Promotes detoxification, mental focus and thyroid health.

Smart Meter Cover -  Reduces Smart Meter radiation by 96%!  (See Video)


FINAL WARNING!   Diseases are EXPLODING!  Watch this Video about APeX and You'll THROW AWAY Your Colloidal Silver!   APeX destroys Viruses, Bacteria and other Pathogens with the power of Oxygen PLUS Silver!  Nobody else has a product like THIS!   See why the inventor hasn't been sick in 16 years and why you'll never hear about it on the FAKE NEWS!  Get some now and tell your friends about it too so we can reach more people!  

APeX Interview - Superior to Colloidal Silver from Lee Canady on Vimeo.

Learn about APeX Here and Get the 50 Page Report in PDF format.   Call us at 888-809-8385 to order by phone.

Report abuse

    Comments

    Your Comments
    Question   Razz  Sad   Evil  Exclaim  Smile  Redface  Biggrin  Surprised  Eek   Confused   Cool  LOL   Mad   Twisted  Rolleyes   Wink  Idea  Arrow  Neutral  Cry   Mr. Green

    SignUp

    Login

    Newsletter

    Email this story
    Email this story

    If you really want to ban this commenter, please write down the reason:

    If you really want to disable all recommended stories, click on OK button. After that, you will be redirect to your options page.