• HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
Thursday, July 24, 2025
BIOENGINEER.ORG
No Result
View All Result
  • Login
  • HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
        • Lecturer
        • PhD Studentship
        • Postdoc
        • Research Assistant
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
  • HOME
  • NEWS
  • EXPLORE
    • CAREER
      • Companies
      • Jobs
        • Lecturer
        • PhD Studentship
        • Postdoc
        • Research Assistant
    • EVENTS
    • iGEM
      • News
      • Team
    • PHOTOS
    • VIDEO
    • WIKI
  • BLOG
  • COMMUNITY
    • FACEBOOK
    • INSTAGRAM
    • TWITTER
No Result
View All Result
Bioengineer.org
No Result
View All Result
Home NEWS Science News Evolution

Theory on origin of animals challenged

Bioengineer by Bioengineer
February 18, 2014
in Evolution
Reading Time: 3 mins read
1
ADVERTISEMENT
Share on FacebookShare on TwitterShare on LinkedinShare on RedditShare on Telegram

One of science’s strongest dogmas is that complex life on Earth could only evolve when oxygen levels in the atmosphere rose to close to modern levels. But now studies of a small sea sponge fished out of a Danish Fjord shows that complex life does not need high levels of oxygen in order to live and grow.

Theory on origin of animals challenged

The origin of complex life is one of science’s greatest mysteries. How could the first small primitive cells evolve into the diversity of advanced life forms that exists on Earth today? The explanation in all textbooks is: Oxygen. Complex life evolved because the atmospheric levels of oxygen began to rise app. 630 – 635 million years ago.

However new studies of a common sea sponge from Kerteminde Fjord in Denmark shows that this explanation needs to be reconsidered. The sponge studies show that animals can live and grow even with very limited oxygen supplies.

In fact animals can live and grow when the atmosphere contains only 0.5 per cent of the oxygen levels in today’s atmosphere.

“Our studies suggest that the origin of animals was not prevented by low oxygen levels”, says Daniel Mills, PhD at the Nordic Center for Earth Evolution at the University of Southern Denmark.
Together with Lewis M. Ward from the California Institute of Technology he is the lead author of a research paper about the work in the journal PNAS.

A little over half a billion years ago, the first forms of complex life – animals – evolved on Earth. Billions of years before that life had only consisted of simple single-celled life forms. The emergence of animals coincided with a significant rise in atmospheric oxygen, and therefore it seemed obvious to link the two events and conclude that the increased oxygen levels had led to the evolution of animals.

“But nobody has ever tested how much oxygen animals need – at least not to my knowledge. Therefore we decided to find out”, says Daniel Mills.

The living animals that most closely resemble the first animals on Earth are sea sponges. The species Halichondria panicea lives only a few meters from the University of Southern Denmark’s Marine Biological Research Centre in Kerteminde, and it was here that Daniel Mills fished out individuals for his research.

“When we placed the sponges in our lab, they continued to breathe and grow even when the oxygen levels reached 0.5 per cent of present day atmospheric levels”, says Daniel Mills.

This is lower than the oxygen levels we thought were necessary for animal life.
The big question now is: If low oxygen levels did not prevent animals from evolving – then what did? Why did life consist of only primitive single-celled bacteria and amoebae for billions of years before everything suddenly exploded and complex life arose?

“There must have been other ecological and evolutionary mechanisms at play. Maybe life remained microbial for so long because it took a while to develop the biological machinery required to construct an animal. Perhaps the ancient Earth lacked animals because complex, many-celled bodies are simply hard to evolve”, says Daniel Mills.
His colleagues from the Nordic Center for Earth Evolution have previously shown that oxygen levels have actually risen dramatically at least one time before complex life evolved. Although plenty of oxygen thus became available it did not lead to the development of complex life.

What is complex life

Complex life differs from primitive life forms such as bacteria and amoeba in several ways – primarily in that they are multicellular, and that cells can differentiate and specialize. Examples of complex life include animals, plants and fungi.

Photo: This is the sponge used in the experiment at University of Southern Denmark, fished out of Kerteminde Fjord in Denmark. Credit: Daniel Mills/SDU.

Story Source:

The above story is based on materials provided by University of Southern Denmark.

Share12Tweet8Share2ShareShareShare2

Related Posts

IMAGE

Artificial intelligence finds surprising patterns in Earth’s biological mass extinctions

December 10, 2020
IMAGE

First-known fossil iguana burrow found in the Bahamas

December 9, 2020

‘Spooky Interactions’, shocking adaptations discovered in electric fish of Brazil’s Amazon

December 9, 2020

New evidence: Neandertals buried their dead

December 9, 2020
Please login to join discussion

POPULAR NEWS

  • Blind to the Burn

    Overlooked Dangers: Debunking Common Myths About Skin Cancer Risk in the U.S.

    60 shares
    Share 24 Tweet 15
  • AI Achieves Breakthrough in Drug Discovery by Tackling the True Complexity of Aging

    70 shares
    Share 28 Tweet 18
  • USF Research Unveils AI Technology for Detecting Early PTSD Indicators in Youth Through Facial Analysis

    42 shares
    Share 17 Tweet 11
  • Dr. Miriam Merad Honored with French Knighthood for Groundbreaking Contributions to Science and Medicine

    46 shares
    Share 18 Tweet 12

About

We bring you the latest biotechnology news from best research centers and universities around the world. Check our website.

Follow us

Recent News

Additive Manufacturing of Monolithic Gyroidal Solid Oxide Cells

Machine Learning Uncovers Sorghum’s Complex Mold Resistance

Pathology Multiplexing Revolutionizes Disease Mapping

  • Contact Us

Bioengineer.org © Copyright 2023 All Rights Reserved.

Welcome Back!

Login to your account below

Forgotten Password?

Retrieve your password

Please enter your username or email address to reset your password.

Log In
No Result
View All Result
  • Homepages
    • Home Page 1
    • Home Page 2
  • News
  • National
  • Business
  • Health
  • Lifestyle
  • Science

Bioengineer.org © Copyright 2023 All Rights Reserved.