Changes

Now to assert, as [[Charles Darwin]] did, that all of life derives from a single ancestor, necessarily requires a great deal of time—[[deep time]], to be specific. Enter Sir [[Charles Lyell]], a [[geology|geologist]] and a [[law]]yer who used his considerable skill as a [[rhetoric]]ian, more than any true [[science|scientific]] insight, to argue that ''the same processes in operation today for the formation and laying down of rock have always operated for all eternity.'' This is the classic position of [[uniformitarianism]]. Technically, uniformitarianism is a concept unique to geology. But [[astronomy]] largely copied Lyell's ideas and came up with uniformitarian ideas of their own.

Now to assert, as [[Charles Darwin]] did, that all of life derives from a single ancestor, necessarily requires a great deal of time—[[deep time]], to be specific. Enter Sir [[Charles Lyell]], a [[geology|geologist]] and a [[law]]yer who used his considerable skill as a [[rhetoric]]ian, more than any true [[science|scientific]] insight, to argue that ''the same processes in operation today for the formation and laying down of rock have always operated for all eternity.'' This is the classic position of [[uniformitarianism]]. Technically, uniformitarianism is a concept unique to geology. But [[astronomy]] largely copied Lyell's ideas and came up with uniformitarian ideas of their own.

Near the beginning of the twentieth century, the notion that the [[earth]] and the [[universe]] were infinitely old became untenable. So uniformitarianism no longer holds to that idea. But it ''does'' hold to the basic idea of deep time, in space and on the earth, with ages for the universe and the earth measured in the billions of years. Astronomers invented a new [[cosmology]] called the [[Big Bang]] to explain the universe, and the [[nebula hypothesis]] to explain the [[sun]], the [[earth]], the [[moon]], and all the [[planets]] (to paraphrase [[Harry Truman]]). But in fact, the only reason why astronomers date the [[solar system]] at 4.6 billion years old is that the geologists date the earth at 4.5 billion years old.

Near the beginning of the twentieth century, the notion that the [[earth]] and the [[universe]] were infinitely old became untenable. So uniformitarianism no longer holds to that idea. But it ''does'' hold to the basic idea of deep time, in space and on the earth, with ages for the universe and the earth measured in the billions of years. Astronomers invented a new [[cosmology]] called the [[Big Bang]] to explain the universe, and the [[nebula hypothesis]] to explain the [[sun]], the [[earth]], the [[moon]], and all the [[planet]]s (to paraphrase [[Harry Truman]]). But in fact, the only reason why astronomers date the [[solar system]] at 4.6 billion years old is that the geologists date the earth at 4.5 billion years old.

Finally, neither Darwin nor any of his contemporaries bothered to assert how life began to begin with. But modern proponents of the paradigm now boldly assert that life began from non-life, a principle that they call [[abiogenesis]]. (Others have flirted briefly with concepts like [[panspermia]] and even [[Panspermia#Directed panspermia|directed panspermia]], but they are in the minority, and many of them, like [[Francis Crick]], have since abandoned such ideas as untenable, or perhaps unsaleable.)

Finally, neither Darwin nor any of his contemporaries bothered to assert how life began to begin with. But modern proponents of the paradigm now boldly assert that life began from non-life, a principle that they call [[abiogenesis]]. (Others have flirted briefly with concepts like [[panspermia]] and even [[Panspermia#Directed panspermia|directed panspermia]], but they are in the minority, and many of them, like [[Francis Crick]], have since abandoned such ideas as untenable, or perhaps unsaleable.)