[Cyanobacteria–green, brown, and orange streaks–grow in hot spring at Yellowstone National Park. Photo by Harvey Barrison via Flickr & Creative Commons 2.0]
The troublemakers were hardly new to the neighborhood. For 300 million years, they had lived in the water column, floating in the sunlight near the surface, sending tiny plumes of toxic gas into the air. That was how they ate: sunlight in, poison out. But it was nothing the ecosystem couldn’t handle. The atmosphere was vast, and the troublemakers were microscopic. The poison diffused. Life went on.
Until something changed. For some reason, there were more of the green troublemakers. Quadrillions more. So many more that their poison became the air itself. An entire world’s atmosphere transformed. Those that could tolerate the miasma grew and spread. Others survived in pockets of the planet where the new air couldn’t reach them. Uncountable numbers died.
The sunlight-eating oxygen-makers inherited the Earth.
In other words, 2.3 billion years ago, photosynthesis caused a mass extinction.
Continue reading “The (Mostly) Untold Story of the Oxygen Revolution” »
“Planetary Changes from Deep Time to the 4th Kind”
In Plain English:
Life doesn’t just adapt to geochemical features; it transforms them simply by…living.
Andrew Knoll of Harvard and David Grinspoon of the Planetary Science Institute
Planet and Life Series, sponsored by MIT Earth, Atmospheric, and Planetary Sciences dept. (EAPS)
What it covered:
Climate shapes life. This is a fact. But when you get right down to it, life is not a fragile, softly-treading phenomenon; every living cell is an interlocking network of chemical reactions. Nutrients and resources are taken in; other chemicals get spewed out.
It would be rather amazing if all those living organisms didn’t have some effect on the non-living environment. But what kinds of impacts? And how can we, as humans with advanced technology, understand and predict the effects our actions will have on the environment?
These are the questions being addressed by The Planets and Life Series at MIT, and the kick-off event, held back in September (unfortunately, I do not get paid to write this blog) was a doozy. Continue reading “Gaia Theory, “Irresponsible Heroes”, & Why We’re Like Cyanobacteria- Recap of talk by Dr. Andrew Knoll & Dr. David Grinspoon” »