Jon Husson, a geoscience postdoc at the University of Wisconsin-Madison, sits by an outcrop of black shale in Nova Scotia, where he gets a bright idea. His insight, according to an announcement from UWM:
For the development of animals, nothing — with the exception of DNA — may be more important than oxygen in the atmosphere.
Oxygen enables the chemical reactions that animals use to get energy from stored carbohydrates — from food. So it may be no coincidence that animals appeared and evolved during the “Cambrian explosion,” which coincided with a spike in atmospheric oxygen roughly 500 million years ago.
It was during the Cambrian explosion that most of the current animal designs appeared. [Emphasis added.]
We all know that correlation is not causation. Does Husson assert that oxygen caused animals to appear? Well, he notes the distinction:
“It’s a correlation, but our argument is that there are mechanistic connections between geology and the history of atmospheric oxygen,” Husson says. “When you store sediment, it contains organic matter that was formed by photosynthesis, which converted carbon dioxide into biomass and released oxygen into the atmosphere. Burial removes the carbon from Earth’s surface, preventing it from bonding molecular oxygen pulled from the atmosphere.”
So far so good. One can buy the argument up to this point. But what about those animals? Professor Shanan Peters comes forward.
“Burying the sediments that became fossil fuels was the key to advanced animal life on Earth,” Peters says, noting that multicellular life is largely a creation of the Cambrian.
A “creation”? But who or what used the key to open a door? Who is the “creator,” and how was multicellular life “created”? Shanan holds a trilobite in his hand. Instead of asking those questions, he asks, “Why is there oxygen in the atmosphere?”
It’s a fair question, but Tenenbaum spoke of “the development of animals.” He mentioned the Cambrian explosion. He says animals “appeared and evolved.” By implication, he seems to be saying: bury carbon, release oxygen, and…well, what do you know? Animals, created by the Cambrian explosion.
It would be good to hear a little more about the DNA referenced in the first sentence. As far as we know, oxygen does not “create” DNA or the coded information it famously contains.
Photo: Trilobite in black shale, by Jon Husson and Shanan Peters/UW-Madison.