historical geology

Do impacts trigger extinctions? Impact theory still controversial

The revolution started with a bang in 1980. For some, this revolution became a religion, even an orthodoxy. The true believers became proselytes and began to see signs supporting their viewpoint everywhere. But each time the proselytes claimed to have found yet another example in support of their “religion,” naysayers and doubters emerged. Two sides formed, each loudly castigating and questioning their opponents.

This back-and-forth ideological debate describes both the historical and still-ongoing struggle over a purported cause of mass extinctions: the meteor impact theory.

23 Jun 2010

Benchmarks: "On the Origin of Species" published

November 22, 1859

About a decade ago, I was fortunate enough to hold in my hands a first edition of Charles Darwin’s “On the Origin of Species.” The green cover was cracked and frayed. The cardboard backing protruded through the torn corners. I put the book down and stared at it in awe. The owner of this book was Asa Gray, one of America’s greatest botanists, an important early American supporter of natural selection, and a friend of Darwin’s.

23 Nov 2009

Benchmarks: "Bone Wars" heat up

March 1, 1872

Edward Drinker Cope stood before a smoke-filled audience at the American Philosophical Society in Philadelphia, Pa., on March 1, 1872. One of the nation’s leading paleontologists, Cope would present his latest fossil find: an extinct flying reptile he designated Ornithochirus. Certainly the piece would be recognized as a major contribution to the scientific understanding of ancient life. More importantly, Cope thought, he would receive credit as its discoverer.

27 Feb 2009

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