ericmurphy
Posts: 2460
Joined: Oct. 2005
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| Quote (afdave @ Jan. 11 2007,05:02) | | Eric ... It seems contradictory to me to say (as Russell says) that life is inevitable, while at the same time admitting that life is very contingent, i.e. bacteria appear for 5by of the 15by available, modern humans appear for 205,000 (200,000 already + 5000 more or so if you believe Crow as Russell seems to). Especially when you throw in the fact that the fossil record indicates species stability (i.e. fossil cyanobacteria is very similar to modern http://www.ucmp.berkeley.edu/bacteria/bacteriafr.html |
Why, Dave? Where's the contradiction? For some period of time (from 9.4 by after the birth of the universe until 14.2 by after the birth of the universe), a particular planet (earth) is congenial for the appearance and evolution of life. Outside of that five-billion-year-wide window of time, it isn't.
Russell isn't actually saying this (although you think it is), but for all we know life was practically inevitable given the environment. Even if it wasn't—even if the appearance of life was extremely unlikely—it did, in fact, arise. Once life has arisen, unless it develops an error-free method of replication, evolution itself is an inevitability (think about it for two seconds, Dave; how could it not be?).
How can you say the fossil evidence supports the idea of "species stability," Dave, when it's a rare species that remains in existence for more than a few million years? With a few rare exceptions (bacteria, sharks), life has changed dramatically over the last three billion years. Any paleontologist can instantly recognize the difference between Ediacaran fauna and Pleistocene fauna. Doesn't that present a slight problem for your claim that "the fossil record indicates species stability"? It does nothing of the sort.
That there are some taxa that have changed dramatically over time and others that have changed very little is evidence that different taxa evolve at different rates. That's all.
Your argument isn't making any more sense than it ever did, Dave, and constantly rephrasing it doesn't help. Life arose on earth, and eventually it will disappear. Where's your problem with this? Your own world view predicts exactly the same thing (albeit on a vastly accelerated time-scale), so surely you're not claiming there's some sort of implied internal contradiction.
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2006 MVD award for most dogged defense of scientific sanity
"Atheism is a religion the same way NOT collecting stamps is a hobby." —Scott Adams
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