According to some Christian outlooks we were made for another world. Perhaps, rather, we were made for this world to recreate, reclaim, redeem, and renew unto God's future aspiration by the power of His Spirit. - R.E. Slater
Secularization theory has been massively falsified. We don't live in an age of secularity. We live in an age of explosive, pervasive religiosity... an age of religious pluralism. - Peter L. Berger
Exploring the edge of life and faith in a post-everything world. - Todd Littleton
I don't need another reason to believe, your love is all around for me to see. – anon
Thou art our need; and in giving us more of thyself thou givest us all. - Khalil Gibran, Prayer XXIII
Be careful what you pretend to be. You become what you pretend to be. - Kurt Vonnegut
Religious beliefs, far from being primary, are often shaped and adjusted by our social goals. - Jim Forest
People, even more than things, need to be restored, renewed, revived, reclaimed, and redeemed; never throw out anyone. – anon
Certainly God's love has made fools of us all. - R.E. Slater
An apocalyptic Christian faith doesn't wait for Jesus to come, but for Jesus to become in our midst. - R.E. Slater
Christian belief in God begins with the cross and resurrection of Jesus, not with rational apologetics. - Eberhard Jüngel, Jürgen Moltmann
Our knowledge of God is through the 'I-Thou' encounter, not in finding God at the end of a syllogism or argument. There is a grave danger in any Christian treatment of God as an object. The God of Jesus Christ and Scripture is irreducibly subject and never made as an object, a force, a power, or a principle that can be manipulated. - Emil Brunner
Ehyeh Asher Ehyeh means "I will be that who I have yet to become." - God (Ex 3.14)
Our job is to love others without stopping to inquire whether or not they are worthy. - Thomas Merton
The church is God's world-changing social experiment of bringing unlikes and differents to the Eucharist/Communion table to share life with one another as a new kind of family. When this happens we show to the world what love, justice, peace, reconciliation, and life together is designed by God to be. The church is God's show-and-tell for the world to see how God wants us to live as a blended, global, polypluralistic family united with one will, by one Lord, and baptized by one Spirit. – anon
The cross that is planted at the heart of the history of the world cannot be uprooted. - Jacques Ellul
The Unity in whose loving presence the universe unfolds is inside each person as a call to welcome the stranger, protect animals and the earth, respect the dignity of each person, think new thoughts, and help bring about ecological civilizations. - John Cobb & Farhan A. Shah
If you board the wrong train it is of no use running along the corridors of the train in the other direction. - Dietrich Bonhoeffer
God's justice is restorative rather than punitive; His discipline is merciful rather than punishing; His power is made perfect in weakness; and His grace is sufficient for all. – anon
Our little [biblical] systems have their day; they have their day and cease to be. They are but broken lights of Thee, and Thou, O God art more than they. - Alfred Lord Tennyson

Thursday, February 20, 2014

Exloring Evolution Series: Early Atmospheric Oxygen Production in Earth History


Photo showing one-billion-year-old weathering profiles from Michigan. Ancient soils like these provide
evidence for low atmospheric oxygen levels through much of Earth's history.
Credit: Noah Planavsky.

The ups and downs of early atmospheric oxygen
http://m.phys.org/news/2014-02-ups-downs-early-atmospheric-oxygen.html

Feb 19, 2014

A team of biogeochemists at the University of California, Riverside, give us a nontraditional way of thinking about the earliest accumulation of oxygen in the atmosphere, arguably the most important biological event in Earth history.

A general consensus asserts that appreciable first accumulated in Earth's around 2.3 billion years ago during the so-called Great Oxidation Event (GOE). However, a new picture is emerging: Oxygen production by photosynthetic cyanobacteria may have initiated as early as 3 billion years ago, with oxygen concentrations in the atmosphere potentially rising and falling episodically over many hundreds of millions of years, reflecting the balance between its varying photosynthetic production and its consumption through reaction with reduced compounds such as hydrogen gas.

"There is a growing body of data that points to and accumulation in the ocean and atmosphere long before the GOE," said Timothy W. Lyons, a professor of biogeochemistry in the Department of Earth Sciences and the lead author of the comprehensive synthesis of more than a decade's worth of study within and outside his research group.

Lyons and his coauthors, Christopher T. Reinhard and Noah J. Planavsky, both former UCR graduate students, note that once oxygen finally established a strong foothold in the atmosphere starting about 2.3 billion years ago it likely rose to high concentrations, potentially even levels like those seen today. Then, for reasons not well understood, the bottom fell out, oxygen plummeted to a tiny fraction of today's level, and the ocean remained mostly oxygen free for more than a billion years.

The paper appears in Nature on Feb. 19, 2014.

"This period of extended low oxygen spanning from roughly 2 to less than 1 billion years ago was a time of remarkable chemical stability in the ocean and atmosphere," Lyons said.

His research team envisions a series of interacting processes, or feedbacks, that maintained oxygen at very low levels principally by modulating the availability of life-sustaining nutrients in the ocean and thus oxygen-producing photosynthetic activity.

"We suggest that oxygen was much lower than previously thought during this important middle chapter in Earth history, which likely explains the low abundances and diversity of eukaryotic organisms and the absence of animals," Lyons said.

The late Proterozoic—the time period beginning less than a billion years ago following this remarkable chapter of sustained low levels of oxygen—was strikingly different, marked by extreme climatic events manifest in global-scale glaciation, indications of at least intervals of modern-like oxygen abundances, and the emergence and diversification of the earliest animals. Lyons notes that the factors controlling the rise of animals are under close scrutiny, including challenges to the long-held view that a major rise in atmospheric oxygen concentrations triggered the event.

"Despite the new ideas about animal origins, we suspect that oxygen played a major if not dominant role in the timing of that rise and, in particular, in the subsequent emergence of complex ecologies for animal life on and within the sediment, predator-prey relationships, and large bodies" said Lyons. "But, again, feedbacks always rule the day. Environmental change drives evolution, and steps in "the progression of life" changes the environment." [similar to the idea of an "anthropocene age" today that posits "industrial mankind as a geophyical force affecting earth's sustainable environment." - r.e. slater]

No single factor is likely to be the whole story, and there is much more to be written in the tale. Lyons and coauthors, along with research groups from around world over, are focusing current efforts on the timing and drivers of oxygenation in the late Proterozoic, favoring a combination of global-scale mountain building, evolutionary controls on the way carbon is cycled in the biosphere, and concomitant climate events.

"We are faced with a lot of chicken-and-egg questions when it comes to unraveling the timing and sequence of oxygenation of the ocean and atmosphere," Lyons said. "But now, armed with new and better data, more sophisticated numerical simulations, and highly integrated investigations in the lab and the field, Earth's oxygenation history seems much longer and more dynamic than envisioned before, and we are getting closer to understanding the mechanisms behind such change."

More information: Study paper: http://dx.doi.org/10.1038/nature13068
Provided by University of California - Riverside