Tag Archives: noah planavsky

Lack of oxygen delayed the appearance of animals on Earth

Geologists are letting the air out of a nagging mystery about the development of animal life on Earth.

Scientists have long speculated as to why animal species didn’t flourish sooner, once sufficient oxygen covered the Earth’s surface. Animals began to prosper at the end of the Proterozoic period, about 800 million years ago — but what about the billion-year stretch before that, when most researchers think there also was plenty of oxygen? (more…)

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Research in the news: The rise of oxygen on Earth

Yale’s Noah J. Planavsky and collaborators have published a Nature review article titled “The rise of oxygen in Earth’s early ocean and atmosphere.”

Published online Feb. 19, the review surveys and assesses research about the emergence of significant oxygen concentrations and suggests that this happened hundreds of millions of years before the “great oxygenation event” of 2.3 billion years ago. In between, oxygen levels appear to have fluctuated considerably, according to the authors. (more…)

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New Evidence Supports Snowball Earth as Trigger for Early Animal Evolution

Geologist Noah Plavansky examines rocks deposited after a "Snowball Earth" glacial event. Image credit: Lyons Lab, UC-Riverside

*Spike in ancient marine phosphorus concentrations linked to emergence of complex life*

Biogeochemists have found new evidence linking “Snowball Earth” glacial events to the rise of early animals. The research was funded by the National Science Foundation (NSF).

Study results appear in this week’s issue of the journal Nature.

The controversial Snowball Earth hypothesis posits that, on several occasions, the Earth was covered from pole to pole by a thick sheet of ice lasting for millions of years.

These glaciations, the most severe in Earth history, occurred from 750 to 580 million years ago. (more…)

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