luvluv

The point is, how do you GET six billion well-adapted organisms (FROM ONE STARTING ORGANISM) in the first place?

The one percent number could maybe do impressive work with a large population, but starting from ONE organism, as evolution presumes? It's hard for me to believe. I think it's much more likley that such an organism gets itself killed off, and that very early, from sheer bad luck than that it lives on to produce EVERY THING we see today.

RBH:

I would think the fact that I'm here, and that I'm willing to learn and even open to accepting evolution should my objections be overcome, would be enough to suggest that I am worth the time.

I simply refuse to believe that evolution is true because somebody tells me it's true. I refuse to silence my own doubts on the basis of someone else's authority without asking a few questions first. I thought that kind of attitude was supposedly prized among atheists.

Does freethinking only allow one to be skeptical about God, and nothing else? Tell me, what do I have your permission to be skeptical about?

Doubting Didymus

The whole point about organisms is that they replicate. If you do get ONE replicator, you soon have loads of them. Plus, they wouldn't have anything to compete with, or need to 'hunt' anything. Whats so hard to believe about a string of replicating RNA appearing and sticking around for long enough to obtain a mutation or two?

luvluv

They'd have to compete with each other, plus the generally unhealthy stuff that just happens. Lightning, falling rocks, fires, meteors, some unhealthy chemicals.

I've always been of the opinion, since I was a lad in science class, that it is just as likely that the first organism would have died as a result of a totally accidental occurance than it is that it would have reproduced. I mean, in my imagination I don't see warm little pools with the perfect chemicals in them (I'm told that this was not the case, at any rate). I see a world as chaotic as the one we live in, probably worse. I see earthquakes, tornadoes, volcanoes, hurricanes, rockslides, mudslides. Heck, I would think even a violent rainstorm could sufficiently do in a nascent life form. I've always doubted that the first organism would get off the ground, given those odds. I guess people who believe in the theory tend to see everything in the best possible light, but that's just not how my brain works. If an opinion or a worldview cannot survive given the worst possible conditions, then I have no faith that it can work at all. (Which is probably why I hang out here.) I can't believe in any scientific system which necesitates that I always assume the optimum conditions obtained. Optimum conditions NEVER obtain, so any practical scientific theory has to be able to work given the WORST POSSIBLE conditions in order to compel my belief. And in my opinion, evolution requires me to supress my unbelief over and over again at different junctures along the way (and no where more than in the origin of life, though I know that this is a different subject. I've never been able to separate the two in my mind).

Doubting Didymus

What about deep sea hydrothermal vents?

Besides, what makes you think that the replicator couldn't replicate a few times BEFORE something wipes it out. All the things you mention aren't the most ubiquitous of occurances. It's entirely possible that replicating things started and quickly died many times, but you only need it to succeed ONCE, and then its damn near impossible to get rid of. All the replicator really needs is a few years worth of favourable conditions before it's widespread enough to survive localised disasters, and then it can take off.

RufusAtticus

You are correct to believe this, since complex traits are the product of many mutations incrementaly adding up together.

Typical eukayrote mutation rates are on the order of 10e-10 changes per nucleotide per replication. Now for humans which have 3.2 gbp per haploid genome, this translates into one point mutation per haploid genome every three cell divisions. Given the many cell divisions that it takes for a germline to go through a generation, each human can inherit hundreds of point mutations from their parents. Now even with a very low beneficial mutation rate of say 1 in 10000, a group of 1000 kids will have multiple beneficial mutations. So when taken over the entire population beneficial mutations are not that rare after all.

Do the math. If Phenotype A outreproduces Phenotype B by 1%, what is the probability that Phenotype A surpasses B? (Try playing with this simulation and this one.)

If the one that can detect light is better able to acquire energy and thus divide faster, then it will out compete.

RufusAtticus

Well when a mommy and a daddy are in love. . . .

MrDarwin

luvluv, thanks for coming back. You asked about ID in general and about Johnson's book "Darwin on Trial" in particular, so we've given you our opinions.

And Johnson doesn't really discuss ID much--his goal is to discredit evolution, and personally I think he's done a pretty poor job of it.

So... you are asking us to educate you about a subject you find boring: that's a rather difficult request, you know.

I've tried to point out before, evolution isn't a theory that makes claims, it is a theory that ties together and makes sense of our observations about the natural world and of the many hypotheses that have been formulated (and tested) to explain them. If you think evolution is wrong, you need to examine the underlying hypotheses, which to a certain extent you do:

And it doesn't. As I've pointed out numerous times, extinction, especially mass extinctions, also play a significant role.

Not from a mutation, but from accumulations of many, many mutations over many, many generations. I know you understand that distinction, but it bears repeating.

And yet overall we're finding that animals are quite similar genetically. The human and mouse genomes are not as different as we once expected from such different organisms that diverged sometime more than 50 million years ago. We share many of the exact same genes, although these genes have sometimes diverged in their precise sequences. Small differences have large effects.

Another pattern we observe is that when groups first diverge in the fossil record, they are very similar to each other, and to their immediate ancestors. This is true of the first tetrapods and their fish ancestors, this is true of the first reptiles and their tetrapod ("amphibian") ancestors, this is true of the first mammals and their reptile ancestors, this is true of the first birds and their dinosaur ancestors, this is true of the first humans and their ape ancestors. So we can say the difference between crocodile and a lungfish is a big one, but the differences between their ancestors become smaller and smaller the further back we look into the fossil record, and presumably are due to smaller and smaller genetic differences. Evolution explains this pattern, which is a very real one that is repeated over and over in the fossil record (denials by YECs notwithstanding).

But mutations happen all the time. Mutations are extremely common (although the vast majority have no effect whatsoever).

Actually, I think "Murphy's Law" is quite relevant to evolution, if it means things like asteroid impacts, massive epidemics, and other unpredictable events that may wipe out populations and even entire species. And such events play a crucial role in evolution. Small advantages (and even neutral differences) may make a big difference when you're one of only a few individuals left in a species.

luvluv, the only advice I can really give you is to continue to educate yourself, continue to ask questions and keep an open mind, but above all, be skeptical of what you're told (but especially by the creationists and IDers).

Non-praying Mantis

Luvluv,

I think that when it comes to evolution and abiogenesis, you seem to have the reverse of tunnel vision. All you can see is the big picture and how large/impressive/diverse it appears.

However, you are failing to see one step at a time. Evolution is an incremental process where one step, after being taken is added on top of those steps that have come before.

Richard Dawkins discusses this in his book Climbing Mount Improbable. It seems that you can only see the huge cliff face in front of you and you either fail to see or do not want to see the gradual path up the other side of the cliff face. Evolutionary processes use the gradual path, with each step being small, but cumulatively, they allow the cliff to be scaled and the top reached. (note - I have paraphrased Richard Dawkins idea here, but I don't have Climbing Mount Improbable with me to give an exact reference)

You do have a very good point here, but if conditions are present all over the planet that allow for living things to arise, then that is exactly what will happen given enough time. Perhaps life got a tenuous start, then got wiped out, then started again, then wiped out, etc. But what is required is that once life sucessfully maintains its hold on this planet, it would be harder and harder for localized disasters to eliminate all of it. We don't know how many times life got started then wiped out. But this is not very important to the overall picture, if it could get a foothold once. That is all it needs. Remember that the above scenario is representative of abiogenesis, not evolution.

Perhaps God did start life off. Do you think that God would allow for life to get wiped out if life is the desire of God?
[disclaimer - of course I don't believe that God actually did this, but I have no way of knowing otherwise. More importantly, I don't see the need for it, and I don't see any evidence for it.]

With life in place, evolution can then proceed by using millions of simple steps to conquer the cliff of today's diversity. Has God taken a hand in evolution? I don't know. Of course, again, I do not believe that God has, but I could be wrong. Again, I see no evidence of this happening, nor do I think that it is necessary. The ID movement, however, states that God (or some unknown designer) is necessary to the process. Evidence for this, I do not see, nor do the vast majority of other scientists who have looked at the evidence.

NPM

Peez

Perhaps if you told us what these "sweeping claims" are that you think evolution makes we could focus a little better.With all due respect, you appear to know little about it.Please understand that it is difficult to read someone state that they don't know much about biology, and they are not even interested in learning more, but that they somehow think they know enough to make the kinds of statements about evolution that you have. I am not telling you to stop questioning, but you should understand when people wonder about your possible bias.The number of mutation that have been required is unknown, but mutations are extremely common (you almost certainly have several that you did not inherit from your parents). Also, the notion that any particular proportion of mutations being beneficial is nonsensical. By the way, just for fun, I estimate that in one particular population of one species of mouse living in one particular part of Canada, in the time since the Europeans arrived here (about 0.0005 million years), there have been about 100 billion brand new mutations (for reference, the mouse probably has fewer than 30,000 genes).Please explain. If a trait does not confer sufficient benefit you to give the organism an advantage in reproduction, then it is not favoured by natural selection. If a trait does confer sufficient benefit that it reproduces at a greater rate than others in the population, it is favoured by natural selection. This is simply the definition of natural selection. It is actually easy (relatively) you to calculate how quickly evolution can proceed with even a "slight" advantage you to the trait.I will be honest here: it is hard to believe that you can say that unless you are being blinded by a strong bias. I am not claiming that every photoreceptive cell that occurrs will necessarily be favoured by natural selection. Let us review. You posted:Well, we explained how it could be formed in incremental steps. Then you posted:andWell, we explained how an organism could go from having no photocell to having a photocell, and how the origin of life is outside of evolution (and if you wish to assume that one or more gods were involved at that stage, it changes nothing about evolution). Then you posted:We explained that there were no "gigantic leaps" there, that something that reacts to sugar can easily react to light, that no "big assumption" was made, and what the precurser to a photoreceptor might have been (there is no point in trying to cover all the senses at once, since you have yet to understand even sight). You then posted:This does not seem to have been specifically addressed, although I believe the issues have been covered. Just to be clear:
a) rhodopsin
b) photons (electromagnetic waves) are absorbed by the molecule
c) part of the molecule is non-polar, causing it to embed itself in the membrane
d) I don't know exactly what Wizardry meant, but I would guess he was simply referring to this molecule occurring in a nerve cell that may send impulses to the brain. You posted:etc., apparently misreading my post. I have explained where you were in error.

Now that we have explained how the first photocell could have evolved, and how complex eyes could have evolved from them, you just seem to be ignoring the fact that you objection is without foundation. Instead, you have just asserted that you don't beleive that natural selection works, even though it is not clear that you understand it. In fact, the basic flow of this thread seems to be you stating that you don't believe that something could happen, then asking how it works to that you can tell us why it couldn't have happened. Doesn't it strike you that it is natural for us to surmise that you have a bias here?An amoeba is unicellular, it is made up of only one cell.How can you seriously argue something that you know so little about? An amoeba no more has a "central nervous system" than does a bacterium.It is hard to take you seriously here. If a mutation confers an advantage to the organism, then the organism has a better chance to survive and reproduce than its buddies. Does this mean it definitely will? Of course not. Does that matter? Of course not. Nobody is claiming that sensitivety to light spread in the population the first time that it appeared. On the other hand, you seem to be trying to argue that it could not have appeared, and that it could not spread in the population. We have explained how it could appear and it could spread, and you rebut by arguing that it might not appear and it might not spread. This looks a lot like willful denial.You appear fairly dogmatic, in your own way. This is based on your trying to argue that something couldn't happen before even understanding it.Nobody here is claiming that it is accidental, and this has been explained.You are free to believe what you want, of course, though it is not science at all. Not that only science is worth consideration, but don't confuse your position with a scientific one.

Peez

Peez

Here's a hint: put one cyanobacterium in a pond and watch. Even if it only divides once per day, it would take just over one month to exceed 6 billion.Evolution does not make this assumption. You should learn about something before making claims about what it assumes.Really? Exactly what is going to kill off the cyanobacterium in the pond?There are many reasons that you might be here, but certainly I am willing to give you the benefit of the doubt.Same here.Doubts? Shouldn't you ask questions before deciding if you have doubts?Atheists? What has this got to do with the existance of gods? Are you sure that you are not letting your religion bias you here?Of course not.If you are letting those comments get you this sarcastic, then you should be able to understand why some of your comments tend to make us get a little, um, playful.


Peez