Francis, you wrote in your last blog "Life is everywhere it can be in the universe."
This is the notion of 'filling up'. I don't know if you have ever read the Origin of Species, I had to read two chapters last year and would like to read it all one day but it really helped crystalise some of my views on evolution and the extent to which natural selection works. People say it is a really dull read but I really enjoyed it.
I read the whole book, and was surprised that it wasn't boring! HIs predictions were so accurate on so many levels; it's truly amazing given the little evidence he had to work with. You can listen to it on an MP3 player, by getting the free audio at librivox.org.
We have a lot more filling to do - is this the goal of nature? Will we ever be completely full? When we are, what will happen then? Will we reach equilibrium? Will things still shift and one species finally dominate (unlikely)?
Those are all great questions, some of which I tried to answer in my blog. Here are some more thoughts:
Filling up is the goal of every living thing, but not necessarily of nature, since nature comprises lifeless things like rocks, volcanoes, and the weather.
It's hard to ever be completely full on a planet whose weather and geology is constantly changing. Some planet may have such consistent weather (like Europa, Jupiter's moon) that it might fill up and stay stable for millions of years. However, even in such an environment mutations must occur since the DNA copying process is not flawless. Those mutations will give advantages to a few, which, in turn, will disrupt the temporary balance in the ecosystem, eventually leading to a new equilibrium.
All equilibriums are temporary. This is a message that all environmentalists need to understand so they don't feel so bad about all the changes that are occurring around us. As long as mutations occur, life and eco systems are never in balance for long. If weather and geology change, then the balance is even more fleeting.
That's why it's silly when environmentalists argue that humans have disrupted the balance in nature, like Al Gore argues in his Earth in Balance book.
Many environmentalists claim they believe in Darwin and evolution, but they behave as if the Earth is static. They get upset if an ecosystem changes sometime in their lifetime. They use terms like "invasive species" and "native species" as if the native ones have been there forever, when they invaded that ecosystem at some point. It's just that the environmentalist wasn't around back then, so he laments the "loss of habitat." Environmentalists rarely call all the plants that we cultivate "invasive species," because those are "non native" species that we like.
Environmentalists cry over the extinction of species, when 99.9% of all the species that have ever lived are extinct. They claim that what humans are doing is different than change in the past because this time it's happening so fast and nature can't keep up. However, they ignore the overnight devasting changes brought by super-volcanoes or massive asteroid explosions - both types of events are far more devastating than all the combined "evils" of humanity.
Environmetalists act like our environmental destruction is unprecedented and that the Earth won't be able to deal with it, yet our impact is nothing to other crazy events that preceeded our existence, and somehow we're still here. Indeed, some of those devasting blows helped bring us about.
I'm not suggesting that all environmentalists are idiots or that I disagree with their objectives. I just wish their had a broader perspective sometimes and focused on what matters most (e.g., overpopulation and our sprawling way of life).
I saw a CNN program where they went to Yellowstone National Park and said that the re-introduction of the wolves has made the Yellowstone ecosystem "more healthy" and "brought it back in balance." Before the re-introduction of the wolf, CNN said there were "too many elk" because there wasn't a natural predator to keep them in check. Who are we to decide what is "too many"? The brutal winters of Yellowstone (and the encroachment of humans) keeps the elk's population in check even if the wolves are gone. Indeed, if we got rid of humans in a 1,000 km radius around Yellowstone and let the wolves back, the elk population would be HIGHER than its current numbers! Sure, the wolves lower the elk population, but not as much as other factors.
One hiker on the CDT complained that the African Mustard plant has been introduced in an ecosystem and now that it is "out of control" because "there's nothing that keeps it in check" and that now it's "everywhere."
I said, "Really? So point it out to me."
"Oh, it's not here in New Mexico."
"Then that means something is keeping the African Mustard in check. Otherwise, we'd be walking on top of it right now. And yet it's not even in this state," I pointed out.
Finally, one species will never dominate for long, especially with mutations, plate tectonics, and climate change constantly changing the rules of the game. Our planet is like a giant football game where the rules of game are constantly changing, so every season there are new winners and losers. Other planets may be less dynamic and let one species reign on the top for longer than this planet, but ultimately all kings will be de-throned.
It's possible that there are planets where the genetic copying process is truly 100% flawless and that climate/geology is 100% constant for billions of years.
Although every living thing on Earth uses DNA, it's possible that alien life has a different copying mechanism, call it xDNA. It's possible that xDNA NEVER makes a copying error.
Alternatively, it's possible that the copying environment doesn't induce mutations. Our atmosphere, for example, lets enough DNA damaging UV rays to filter through, inducing mutations. Other planets might have a tougher shield that protects their xDNA from mutations, delaying or eliminating the mutation process.
Whew! That was a long answer to a simple question!
I welcome comments on it.