Archive ScienceWatch



Don E. Canfield talks with and answers a few questions about this month's New Hot Paper in the field of Geosciences.
Canfield Article Title: Late-Neoproterozoic deep-ocean oxygenation and the rise of animal life
Authors: Canfield, DE;Poulton, SW;Narbonne, GM
Journal: SCIENCE
Volume: 315
Issue: 5808
Page: 92-95
Year: JAN 5 2007
* Univ So Denmark, Nord Ctr Earth Evolut, Campusvej 55, DK-5230 Odense M, Denmark.
* Univ So Denmark, Nord Ctr Earth Evolut, DK-5230 Odense M, Denmark.
* Univ So Denmark, Inst Biol, DK-5230 Odense, Denmark.
(addresses have been truncated)

Why do you think your paper is highly cited?

It is always a pleasant surprise when one finds that their work is well received by the scientific community. I think this article has been well received because we provide the first demonstration of oxygen penetrating into the deep waters of the late Precambrian oceans. Importantly, this oxygenation is timed with the emergence of the Ediacaran fauna, some of which may have been early stem-group animals. Therefore, our work supports a causal relationship between the oxygenation of the deep ocean and the evolution of animals.

Does it describe a new discovery, methodology, or synthesis of knowledge?

I would say this work is best described as a new discovery.

Would you summarize the significance of your paper in layman's terms?

Fossil evidence suggests that animals probably evolved sometime around 600 million years ago, and large animals appear around 575 million years ago. Animals have an absolute requirement for oxygen for their respiration, so it has often been speculated that large macroscopic animals (those with the largest oxygen requirement) evolved when oxygen rose to permissible levels, which would be about 10% of those levels we have today. Our study supports this scenario by showing that the first occurrence of large respiring organisms, some of which are likely stem-group animals, emerged on the Avalon Peninsula in Newfoundland in concordance with oxygenation of this local environment.

How did you become involved in this research, and were there any problems along the way?

The history of atmospheric oxygen and its bearing on animal evolution has long been an interest of mine. This particular study evolved through discussions with Guy Narbonne at Queens University in Kingston, Ontario, Canada, who is an expert in Ediacaran fauna, and who had already worked extensively on the Avalon Peninsula in Newfoundland. The study was actually pretty straightforward without any really significant difficulties.

Where do you see your research leading in the future?

We would like to better understand the nature of the evolution of ocean chemistry, and in particular the history of oxygenation of the oceans. This means undertaking an extensive study of numerous different late Precambrian geological formations.

Do you foresee any social or political implications for your research?

This work is definitely nonpolitical. From a societal perspective, I think that this work, and other works like it, helps to shed significant light on the history of biological evolution on Earth. This helps to elucidate the pathways leading to human evolution, and it helps to define Man's place in the biological world. These are issues of fundamental, cross-cultural human curiosity.

Donald Eugene Canfield
Professor, University of Southern Denmark
Director of the Nordic Center for Earth Evolution (NordCEE)
Odense, Denmark

Keywords: late-neoproterozoic deep-ocean oxygenation, precambrian oceans, ediacaran fauna, early stem-group animals, large macroscopic animals, guy narbonne, avalon peninsula in newfoundland, ocean chemistry, oxygenation, biological evolution.


2008 : May 2008 - New Hot Papers : Don E. Canfield