So, life (on Earth) is much older than what was thought...

[Aesmael]

I wouldn't completely rule out the possibility that the pre-lunar Earth already had a reasonably evolved surface. It would have been a fair bit smaller at the time. A couple hundred million years might be enough for some sort of primitive life to emerge.

Except that this was merely the most dramatic example of a regular occurance back then. There simply was not time for it to happen until afterward. The Earth's age was only a couple hundred million years old at the time, anyway.

 

[Desdichado]

You both are actually right: it has a random part (mutation commonly, though I think there are other mechanisms) and a non-random part (selection)

Right, but selection doesn't guide evolution anywhere. That is, a marginally smarter early rat-like mammal isn't on a path towards being an intelligent and sentient creature like a human, unless the marginally smarter trait is actually of some use to it right now. And even then, its not necessarily on that path either; it takes another random bump up, and that random bump up rat-thing has to live long enough to pass on it's genetics, etc.

So, yeah, life forms seem to be evolved to fit their environment fairly well, but Mother Nature didn't guide them to it. Saying that evolution isn't random is a bit like putting the cart in front of the horse, IMO.

 

[tarchon]

A couple hundred million years might be enough for some sort of primitive life to emerge.

Except that this was merely the most dramatic example of a regular occurance back then. There simply was not time for it to happen until afterward. The Earth's age was only a couple hundred million years old at the time, anyway.

Hmm... if only it had been a couple hundred million years, then some sort of primitive life might have emerged.

 

[Aesmael]

Ya, could have been interesting.

 

[Turanil]

Dreamlands?

LOL!

I'll repeat - heat isn't selective. If it destroys fossils, it destroys them all.

Well, best would be that you could get the opportunity to see this documentary to get an opinion. They said (more long and complex than what I retell here, of course) that the micro-organisms survived because they are almost everywhere. So, they also were in water pockets deep into Earth crust. These water pockets weren't vaporised like everything else because (according to the theory) they were "protected" by the deep Earth mantle all around. Now, in such case I believe a micro-organism has better chances to survive than something more complex that needs more specific interaction with its environment. ALSO: this micro-organism is said to resist / survive up to 180 degrees celsius, and can hibernate for one million of years.

 

[RedWick]

Right, but selection doesn't guide evolution anywhere. That is, a marginally smarter early rat-like mammal isn't on a path towards being an intelligent and sentient creature like a human, unless the marginally smarter trait is actually of some use to it right now. And even then, its not necessarily on that path either; it takes another random bump up, and that random bump up rat-thing has to live long enough to pass on it's genetics, etc.

So, yeah, life forms seem to be evolved to fit their environment fairly well, but Mother Nature didn't guide them to it. Saying that evolution isn't random is a bit like putting the cart in front of the horse, IMO.

Never mentioned anything about life/evolution being guided. Just that it's not random (at least, not completely random). I wasn't clear, though, as to what exactly I meant by that. Just meant that the underlying cause behind all of the mutations which occur happen for very discreet and predictable reasons. Randomness *does* comes in when these mutatations interact with eachother. You have this base of non-randomness interacting in a very random manner. The eventual outcome, though, is almost exclusivly non-random though (emergant behavior).

Fractal layering of randomness and non-randomness, from a sub-atomic level to a universal scope. Life is just one facet of that layering. Neat stuff. I've been fascinate by the subject since I was a kid (even if my thoughts weren't particularly sophisticated at the time ). Poke around for stuff about Complexity Theory. Subject is rife with stuff like this.

 

[tarchon]

Never mentioned anything about life/evolution being guided. Just that it's not random (at least, not completely random). I wasn't clear, though, as to what exactly I meant by that. Just meant that the underlying cause behind all of the mutations which occur happen for very discreet and predictable reasons. Randomness *does* comes in when these mutatations interact with eachother. You have this base of non-randomness interacting in a very random manner. The eventual outcome, though, is almost exclusivly non-random though (emergant behavior).

Some of this communication problem lies in misunderstanding the term "random." Random simply means that a process has multiple possible outcomes and that the outcome is not known beforehand. It doesn't mean "anything could happen," as many people seem to think. Evolution is a completely random process, but there are constraints on the possible outcomes.

 

[Someone]

Right, but selection doesn't guide evolution anywhere. That is, a marginally smarter early rat-like mammal isn't on a path towards being an intelligent and sentient creature like a human, unless the marginally smarter trait is actually of some use to it right now. And even then, its not necessarily on that path either; it takes another random bump up, and that random bump up rat-thing has to live long enough to pass on it's genetics, etc.

So, yeah, life forms seem to be evolved to fit their environment fairly well, but Mother Nature didn't guide them to it. Saying that evolution isn't random is a bit like putting the cart in front of the horse, IMO.

Sure, arguments here come in form of semantics and how non-random doesn´t neccesarily mean intelligently planned. Natural selection doesn´t work as a benevolent engineer thinking on long term inprovement of the species, but as a maniac looking for individuals with bad combinations of genes to bash them.

 

[Umbran]

Well, best would be that you could get the opportunity to see this documentary to get an opinion. They said (more long and complex than what I retell here, of course) that the micro-organisms survived because they are almost everywhere.

I'm cool with all that, Turanil. It's a mass extinction. We've evidence for a number of them. You're just positing one slightly bigger, and that I can handle easily enough. That this event might kill off all but the single-celled organisms I can understand.

What I can't easily swallow are the anomalously young moon, and selectively wiping out only some of the fossils that were formed long before the event. Those two catch in my scientific craw.

 

[Angel Tarragon]

Or so archaelogists & scientists say. I don't believe it.