SCIENCE Questions: How and Where Did Life on Earth Arise?

 

"How and Where Did Life on Earth Arise?" is one of the top 25 questions from the 125th anniversary issue of Science magazine [Science, July 1, 2005]. The complete reference is ...

Zimmer, Carl (2005) How and Where Did Life on Earth Arise? Science 309:89. [Text] [PDF]

Carl Zimmer is one of the best science writers on the planet. He has just won the National Academies 2007 Communication Award. It goes with his many other prizes and awards. Carl has a blog [The Loom].

I've criticized many of the other articles in this series because they either misrepresented the science or blew it up out of all proportion. It should come as no surprise that Carl Zimmer's piece does not do that.

The question—how did life originate?—is without a doubt one of the top 25 questions facing us today. The subject is complex but Carl covers it in a single page without resorting to hype or misrepresentation. He mentions the fossil evidence then discusses the idea of an RNA world and how it might have formed. Then he turns his attention to the controversial field of prebiotic chemistry. Here's an example of science writing at its best.

Just where on Earth these building blocks came together as primitive life forms is a subject of debate. Starting in the 1980s, many scientists argued that life got its start in the scalding, mineral-rich waters streaming out of deep-sea hydrothermal vents. Evidence for a hot start included studies on the tree of life, which suggested that the most primitive species of microbes alive today thrive in hot water. But the hot-start hypothesis has cooled off a bit. Recent studies suggest that heat-loving microbes are not living fossils. Instead, they may have descended from less hardy species and evolved new defenses against heat. Some skeptics also wonder how delicate RNA molecules could have survived in boiling water. No single strong hypothesis has taken the hot start's place, however, although suggestions include tidal pools or oceans covered by glaciers.

Research projects now under way may shed more light on how life began.

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