Jesse

Walrus, I don't think anyone here is "avidly embracing" the speculations about life on Venus. It's an interesting possibility to discuss, but I assume everyone realizes it is quite speculative--have you seen anything on this thread to indicate otherwise? The difference between this and creationist theories, though, is that life on Venus does not contradict huge amounts of established evidence in the same way.

Incidentally, the possible evidence for life on Mars from the Mars meteorite has not "flopped" or been discredited as you suggest--it is still very much open to debate, just as it was when the finding was first announced. Here's are some articles that discuss the current state of the controversy:

<a href="http://www.space.com/scienceastronomy/solarsystem/mars_meteorite_020320.html" target="_blank">http://www.space.com/scienceastronomy/solarsystem/mars_meteorite_020320.html</a>

<a href="http://www.planetary.org/html/news/articlearchive/headlines/2001/Meteorite_controversy.htm" target="_blank">http://www.planetary.org/html/news/articlearchive/headlines/2001/Meteorite_controversy.htm</a>

<a href="http://www.kingston.ac.uk/geolsci/cosmochemistry/lifeonmars.htm" target="_blank">http://www.kingston.ac.uk/geolsci/cosmochemistry/lifeonmars.htm</a>

<a href="http://www.lpi.usra.edu/lpi/meteorites/alhnpap.html" target="_blank">http://www.lpi.usra.edu/lpi/meteorites/alhnpap.html</a>

<a href="http://www.angelfire.com/on2/daviddarling/Marsfossils.htm" target="_blank">http://www.angelfire.com/on2/daviddarling/Marsfossils.htm</a>

[ September 28, 2002: Message edited by: Jesse ]</p>

Jesse

Answerer:
Thanks for the link, Jesse. Anyway, are there only two possible kinds of lifeform, silicon and carbon based or is there more?

I think those are the only two types of atoms that can form sufficiently complex molecules, which presumably would be necessary for any kind of "life" composed of atoms (as opposed to exotic non-atomic forms of life like the kind imagined in Robert Forward's book). But as mentioned above there are some other factors that suggest silicon-based life may not be possible, leaving only carbon-based life.

Jeremy Pallant

And this is wrong, why, exactly? Theists make the assertion, it is therefore their responsibility to provide the evidence. Don't blame us because you can't.

Well, at least there's actual evidence behind this theory. That doesn't automatically make this theory true. Certain chemicals have been observed in Venus' atmosphere whose presence is, based on current knowledge, best explained by the presence of life.

This is the theory proposed by Schulze-Makuch and his colleague Louis Irwin.

So, you've got two scientists proposing a theory (hardly all atheists avidly embracing a theory), and...

...there is opposition to this theory. André Brack from the Centre for Molecular Biophysics in Orléans, France is quoted as saying "For life, you need a volume of water, not just tiny droplets."

(scientists opposing the theory)

Actually the jury is still out on the Mars rock. You're erecting a straw man argument. Why not wait until more information is available, and let science do its job? Let's face it, science is far more reliable than religion when it comes to the advancement of technology.


No. Creationists have no evidence to support their wild speculations; after all they do no research of their own.

Indeed not. However there is evidence to suggest that there might be life on Venus, and while the Mars rock remains a controversial subject, it might provide evidence that there was life on Mars. You demand proof, but until we go to Venus, or Mars, or Europa or any other planetary body, the existence of extra-terrestrial life will remain unconfirmed.

The problem is that people like you, as far as I can tell, don't want life to be found elsewhere in the universe.

Why?

Edited for speling.

[ September 28, 2002: Message edited by: Jeremy Pallant ]</p>

WalrusGumBoot

Jeremy:

I am middle of the road on creation/evolution. I guess you can say an "agnostic", which I hate to coin that term for myself being that it reminds me of being a political moderate, i.e. wishy-washy. In politics at least, I am strongly opinionated. Origins of life is much more complex.

It's not that I don't want life to be proven somewhere else. The fact would not prove that a god does not exist, nor will it prove evolution true. If god cannot be proven because he/she/it cannot be seen or heard, then evolutionary theory cannot be proven for the same reasons. Macroeveolution has never been observed, our greatest evidence is the fossil record, but that doesn't "prove" anything.

Since the ability for species to take such large evolutionary leaps is the core of the atheists' belief structure for his origins, and coupled with the fact that nobody has actually seen it happen, it takes faith to believe it. Sounds like religion to me, by definition. I also think science is flawed in that it is too subjective these days. The scientist's bias is often too obvious, whether it be that he wants to disprove god or that some socio-political motives are involved (e.g. global warming).

So, I play the middle of the road for now. I hope before I pass I can make a committment either way, so I won't have "wishy-washy" engraved on my headstone.

Liquidrage

Don't look for macroevolution. It doesn't exist. Well, unless you fall in line with Gould et all that believed in something along those lines.

Microevolution is all there is.
However, is you except microevolution and you except 3+ billion years as the amount of time that life has existed on Earth, then you must present some mechanism that prevents itterations of micoevolutionary changes from becomming distinct kinds and changes that would be described as macroevolution.

So, if you aren't sure about this evolution thing, what do you suppose is that mechanism that stops microevolution over a duration of billions of years? Keeps it close to what it started out as, etc.

WalrusGumBoot

Liquid, of course I must accept microevolution because it can be observed. However, I'm not so sure about 3 billion years as the age of the earth. The burden of proof is not on me that a series of micro changes cannot produce a macro change. It's like asking someone to prove that the Oort cloud doesn't exist out in space.

Edited for spelling.

[ September 29, 2002: Message edited by: WalrusGumBoot ]</p>

Liquidrage

It is nothing like proving the Oort cloud doesn't exist.

Simple microevolution will of course lead to what you are calling marcoevolution if given sufficient time.
Many people can't grasp this. They seem to think that for macroevolution a mutation must occur that gives rise to say an eye from nothing.

Where then does microevolution stops? What in your mind prevents a series of micorevolutionary mutations from further mutating? For that is exactly what you are claiming. That microevolution must stop somewhere.

Else it is not hard at all to show that a large series of micorevolutionary mutations can lead what you are calling macroevolution.

If you can't picture it, add more steps (micro mutations). Still can't picture it? Add more steps. Keep adding more steps until you can fathom macroevolution occuring from the series of small changes.

Now if you debate the age of the Earth with all the information around you, then I can't help you. I can only guess that you have only heard of the techniques used and never bothered to better understand how they work.

ps418

You are invoking exceedingly naive definitions of religion and faith. It is certainly not necessary to "see it happen" to know "that it happened." And conclusions which are based on indirect evidence are nonetheless based on evidence, and thus are hardly matters of faith.

Consider an uncontroversial example. I need not witness a murder to conclude beyond a reasonable doubt that person X is the murderer, that the murder occured at location Y and time Z, with weapon Q. I can show with various lines of indirect evidence that X is the murderer -- he had a motive, he was in the area, he possesses a gun consistent with the murder weapon, a drop of his blood was found at the scene, and so on. My convinction of person X would hardly be a matter of faith, despite the fact that neither I nor anyone else can claim to have witnessed the murder.

You may object that murder is not evolution. But this is irrelevant to the point, which is that hypotheses about unwitnessed past events, at least under some circumstances, can be tested/substantiated/falsified by indirect evidence. In the case of evolution, the fossil record and the genome stand in the place of the murder weapon, and motive, and so on. You may of course disagree with the conclusions drawn from this evidence, but the conclusions hardly constitute "religion" simply because they are based on indirect evidence.

Patrick

[ September 29, 2002: Message edited by: ps418 ]</p>

Jeremy Pallant

Looking at your post, Walrus, it appears to me as if you've been spending more time looking at creationist's criticisms of evolution, rather than studying evolution itself.

If you haven't already been there, an extended visit to <a href="http://www.talkorigins.org" target="_blank">Talk Origins</a> might be of interest.

WalrusGumBoot

Jeremy:

I get my information about evolution mainly from forums these days, from folks who are kind enough to answer my questions instead of making me feel like a dumbsh*t. I wish I could do more reading, but I have a software business to run, help my wife run her business, and taking MBA classes. I am looking for info from people like YOU to inform me. When somebody I know asks me a computer question, I don't tell them they need to go out and read computer books to find the answers for crying out loud, I answer them no matter what level of understanding they have of them.

LiquidRage:

I understand what you are saying, and in theory it makes sense. In real life though, somehow I can't see it happening. For example, I live on a horse ranch and have for a long time. We've bred horses, along with other animals. There have been instances where the newborns were born with a congenital defect (mutation?) where they DIED soon after. The surviving offspring is still a horse, still a dog, still a cow, etc. For practical purposes, exactly like their mama.

Horses have been tamed by man for a long time and have been depicted in stories and pictures. A horse today is just like a horse 2000 years ago. While 2000 years is a drop in a bucket compared to 3 billion years, if an evolutionary leap is nothing more than the accumulative effect of micro changes, shouldn't we see SOME change even over this short period of time? I mean, when would a new "feature" begin to make itself obvious?

A micro change is only permanent anyway if it gives them a breeding advantage to allow them to dominate and take over the gene pool. And wouldn't such a small micro change that doesn't give this advantage be readily diluted by the prevailing population to the point where there is no longer anything to build upon?

You bring up the eye, which is a good example (why TWO of them anyway?) Why on the front or side of the head for nearly all species from mammals to reptiles to birds to insects? Why hadn't some animal which is heavily preyed upon mutated an eye over time on the BACK of the head to see predators better?

I am certainly hoping that these questions are not viewed as juvenile or even imbecilic. I understand they are basic, but even the "high school level science book" do not cover such things. What's your thoughts on this?

Kind Regards,

Walrus

[ September 29, 2002: Message edited by: WalrusGumBoot ]</p>