Poison Creating Life

The debates over the origins of human life are extensive and heated. A discussion generating much fewer strong feelings and less controversy in the everyday world is over the origins of life in general--at an atomic level. A recent article from the magazine New Scientist examines this debate and explores a new option.

Because Earth was formed so close to the sun, scientists doubt that the larger, more complex elements necessary for life would have formed at the planet's birth. Life depends on these elements for molecules to create the basic make-up and processes of cells.

Scientists have suggested many theories, including lightning causing chemical reactions and the possibility that falling comets and asteroids brought organic material, but many conflicts to these theories exist. The most significant argument against comets was previously that they burned up as they entered the atmosphere, converting their organic molecules to carbon dioxide.

Recently, however, scientists working with NASA have come up with a third option: cyanide. Researchers fired projectiles simulating comets hitting the Earth and came up with some surprising results: the impact formed cyanide. The poisonous compound contains nitrogen, an important element in amino acid formation, a basic life function.

These findings add another aspect to the debate, but more scientists still do not agree. Donald Brownlee says that

some of early Earth's organic material undoubtedly formed this way...[but] there were probably other sources too, including organic-rich particles of interplanetary dust, which fall to Earth more gently than asteroids and comets. "It gets warmed but it doesn't get extremely hot."

The discussions over the origins of life will continue despite these new findings, but we can all be sure the end result will assure something we already knew: Life exists on planet Earth.

Solving an Ice Age Mystery

460 million years ago, the Appalachian Mountains in Eastern North America formed. 445 million years ago, the Earth dropped into an ice age so severe, two-thirds of all plants and animals went extinct. Coincidence? Seth Young and his colleagues say not, in this article.

In a write-up for ScienceNOW called "The Mountains That Froze the World", Phil Berardelli explains the theory and science behind the connection for the general public. Shortly after giant volcanic explosions formed the mountains,

...CO₂-laced acid rain fell on the rocks, [and] it formed limestone that washed into the Nevada sea and locked away huge amounts of carbon from the atmosphere. Then, when the volcanism ended, about 450 million years ago, the sequestering continued, thinning CO₂ levels to maybe a few times higher than today. Back then, a dimmer sun couldn't keep the atmosphere warm without CO₂'s help--hence, the eventual onset of the ice age.

These findings do not explain the reason the rise of the Himalayas was followed by an ice age, but they do give a reasonable explanation for this ice age. Among previous explanations was the idea that the ash blown up by the volcanoes themselves blocked the sun, but the dates didn't match.

The original findings published in Geology are a bit indecipherable to a non-scientist, but Berardelli's explanations are clear and much easier to follow. Head on over to ScienceNOW's website through the link above to see the whole article.

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