Freethought & Rationalism Archive

deadman_932 · 06-23-2007, 08:26 PM

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What do you do with Kondrashov? His question ... Why have we not died 100X over?

The correct question to ask in regard to this is: "Given Dave's mangling of Kondrashev, Crow and others --if Dave is correct in his interpretation...why are there so many species left alive ?"

You've previously stated that ...what, 300 generations would be sufficient to cause genomic collapse, Dave? So why are there any species left alive that have easily attained that number and beyond, EVEN IF YOUR NOAH TIME FRAME IS ACCEPTED?

This point, all by itself shows the silliness of your claims, Dave. It also exposes a great hole in your "interpretation"

deadman_932 · 06-23-2007, 08:32 PM

Ever looked at insects in amber, Dave? How many generations do you think extant species underwent since their ancestors were captured in ...well, let's use Dominican amber. That would be a LOT more than the number of generations you say would cause extinction.

You can't claim "bees would be long-lived in the post-diluvian world, so there would be fewer generations"...

wait, I retract that... I bet you CAN actually say that, given your track record and utter ignorance of science.

ericmurphy · 06-23-2007, 09:09 PM

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Originally Posted by afdave

Ok ... So we disagree on Crow. What do you do with Kondrashov? His question ... Why have we not died 100X over?

300 generations, Dave. That's the number you supplied. 300 generations for complex genomes to be driven to extinction.

How many times do we have to go through this? For the vast majority of eukaryotes, 300 generations is comfortably less than 500 years. How long ago was your flood, Dave? 4,500 years ago, right? In rough terms?

So the question for you, Dave, is why are there any eukaryotes left? Why do we not see a progressive diminution of biodiversity over the past 4,000 years? Why do we not see any significant change in biodiversity until the very recent past?

What's your explanation for that, Dave? Do you have one? No? I didn't think so. So why did you bring it up? As usual, you have the impossible-to-answer questions.

Amaleq13 · 06-23-2007, 09:53 PM

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Originally Posted by afdave

Amaleq ... May I ask something? Are you a geneticist? If not ... What is your area of specialty?

I've been a school psychologist for about 18 years but I would like to think I would correctly comprehend Crow's article without having endured graduate school.

I think my advantage over Sanford is that I am reading Crow simply for what he says as opposed to trying to extract something from it that comports with my beliefs.

You have been mislead, Dave. An accurate reading of Crow doesn't deny your beliefs about our ancestors' DNA, it just doesn't provide anything to support them.

Doug

Amaleq13 · 06-23-2007, 10:05 PM

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Originally Posted by afdave

...he cannot see what this implies. It implies that we have a larger load of deleterious mutations.

I asked you before to clarify what you meant by "larger load of deleterious mutations" but you didn't do so. I have never denied that Crow's article suggests modern DNA has more accumulated deleterious mutations than that of humans at least several centuries older. What I have denied is that this statement implies that our ancestors had fewer deleterious mutations naturally occurring in their DNA (ie that their genes were somehow superior).

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Yes, the load is even larger because of medical technology, but it is larger even without the technology. Why do I say that? Because Crow says that if the medical technology goes away, then our increased load puts us in worse shape.

Yes and he tells us exactly why he thinks this and it clearly is not for the reason you suggest:

"If war or famine force our descendants to return to a stone-age life they will have to contend with all the problems that their stone-age ancestors had plus mutations that have accumulated in the meantime." (emphasis mine)

Our stone-age ancestors had deleterious mutations occurring just like we do (ie "all the problems") plus we would have the bonus of the accumulated deleterious mutations that our technology preserved from natural selection. That is why Crow thinks we would have more genetic problems than our ancestors did. Our ancestors did not have that technology so natural selection prevented them from accumulating as many as we have. They only had the naturally occurring deleterious mutations.

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Maybe we should start a John Sanford book thread at some point and go through all the papers he writes about, many of which imply the same thing.

You've already given me enough information about Sanford for me to have no trust in his judgment.

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In the mean time, I will contact Crow and see what he says.

That's great but I really think you can figure this out on your own if you make an effort to carefully reread both my posts and Dean's on Crow.

Sanford has misguided you, Dave.

Doug

mfaber · 06-23-2007, 11:29 PM

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Originally Posted by ericmurphy

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Originally Posted by afdave

Yes. I understand this. I'm not sure what made you think I do not. Crow and Kondrashov's work shows that non-lethal, slightly deleterious mutations are accumulating in populations. And selection is not adequate to remove them prior to extinction of the species. Sanford shows this quite definitively in his book.

Of the human species, Dave. Not all species. That's what they're talking about. But guess what? Almost all species eventually go extinct. This is an observation. Why do you think this presents a problem for evolutionary theory?

And Dave, here's a clue: extinction is a consequence of natural selection. You know that some things (including entire species) are selected against, don't you?

Good evening, all (gladiatrix here from RD.net, my handle here on II is mfaber)! Thought I'd add my 2 centavos.....

A word about extinction... As Eric has observed, 99% of all the species on Earth have become extinct. Is this NECESSARILY a "big bad"? No, as Dr. David Raup explains this in his book Extinction: Bad Genes or Bad Luck?. Here's what he says on this issue (Note: To verify my quotes, go to the Amazon link above...this book has a searchable index):

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From pg. 19
Evolution without extinction suggests several problems. Most important, biodiversity would increase exponentially. The more species lineages that came into being, the more lineages there would be to produce more species. Rather soon, they system would saturate: speciation would have to stop because ther would be no room for new species.

Adaptation by natural selection would continue to hone and refine the existing species, and the ultimate quality of the adaptation might even be greater than what we see today because the species would have more time. The first-formed organisms might have evolved far better structures than the ones visible today.

Evolution eliminates promising lineages-often early in the adaptive process—but this creates space for evolutionary innovations. Therefore, in our world at least, extinction continually provides new opportunites for different organisms that can explore new habitats and modes of life. The process “keeps the pot boiling’ and may be necessary to achieve the variety of life forms, past and present (color, bold added)

Dr. Raup lays out three processes in his book. The three processes, all of which are documented, may have interacted to help produce the resultant life on Earth.

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From pg. 188
Is selectivity important in the fulfillment of extinction'f role in evolution? We have seen, in various contexts in this book 3 extinction modes:

1. Field of Bullets-random extinction without regard to differences in fitness

2. Fair Game: selective extinction in a Darwinian sense, leading to the survival of the most fit or best-adapted species.

3. Wanton extinction: selective extinction, where some kinds of organisms survive preferentially but not because they are better adapted to their normal environment.

Species go extinct because they are playing a form of survivalist roulette, otherwise known as Gambler's Ruin (Chapter 3, page 45).

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From pp. 45-49

Figure 3-1 shows several possible outcomes of the casino scenario.

Though simulated with a random-number generator on a home computer, they could just as easily have been created manually by flipping a coin or drawing randomly from a deco of playing cards, using red and black. In each case, our gambler ultimately went broke, but in one of them (Game #3) he/she did pretty well for a while.

Statisticians have used the Gambler’s Ruin problem, just described in its simplest form, for years as a model of kinds of probability. Inevitably, a specialized language has grown up around Gambler’s Ruin. For example, the paths followed by the gambler’s fortunes in Figure 3-1 are called random walks. Once started, the random walk has no tendency to return to a level previously occupied. If the gambler starts with ten dollars, no force induce the path to stay near ten or return to ten. The system has no memory. Every good gambler knows this, of course: a long string of failures does not change the odds for the future.

The horizontal base of each graph in Figure 3-1 denotes a zero stake--the level at which the gambler has lost the original stake and is broke. This is called an absorbing boundary because if the path reaches this level, there is no return; the game is over. We could change this condition by stipulating that when you go broke, the casino gives you a single dollar to keep going. In that case, the bottom of the graph becomes a reflecting boundary--you bounce back with at least one upward step. I know of no casino that does this except by offering credit.

In Game #3 of Figure 3-1, the gambler's stake dropped from 10 to 1 early in the play, then rose to 14, and ultimately dropped to 0 (the absorbing boundary). Suppose the gambler had started with nine instead of ten dollars and the play was otherwise identical. Zero would have been hit in that initial drop, and the gambler would never have enjoyed the later success--and the opportunity to leave with a small profit. This emphasizes the importance of the size of the initial stake: the higher it is, the farther it is from the absorbing boundary and the more likely that the gambler will remain in the game for a long time.
. . . .
In the extinction context, we may think of the gambler's stake as the number of species in an evolutionary group. Our example's initial stake of 10 might be a genus with 10 species living at some instant in the geologic past. We will use a time scale of millions of years instead of the gambler's time scale. For every interval of one million years, each species has a fifty-fifty chance of surviving to the start of the next million-year interval; if it survives, it has a fifty-fifty chance of speciating to produce an additional species. What predictions can we make about the fate of the genus?

Several interesting predictions are possible. For example, the number of species (diversity) will fluctuate up and down as in a random walk. Extinction of species lowers diversity; speciation increases diversity. As long as the chance of extinction is identical to that of speciation (fifty-fifty), a random walk will result.

Furthermore, eventual extinction of the genus is inevitable. This is somewhat counterintuitive, but it follows from the presence of the single absorbing boundary at zero species. As we have seen, a random walk is free to wander up and down indefinitely. If there is no upper absorbing boundary [NOTE: the "house" losses, the equivalent of breaking the bank], the random walk is bound to hit the lower boundary eventually.

We could, of course, specify an upper absorbing boundary, analogous to the casino's total assets. In the context of global biology, the upper absorbing boundary would be all the spaces for organisms in the world. An evolutionary group, such as a genus, could, "break the bank" by speciating so many times that no other genus could exist. All species in the world would belong to the same genus. This is as unlikely as an ordinary gambler's winning the whole casino. Thus for all practical purposes, the ultimate extinction of the genus is assured. (bold added)

Just for fun, play Gambler's Ruin here and read more about Gambler's Ruin at Wiki.

Humans are playing their own unique form of "the game" (bad genes?). We can do what no other species can (as far as we know), i.e., alter the survival rate of individual members, using modern technology.

Again, Crow points out that this allow us to maintain the survival of individuals that would have died before reproductive age or at least had fewer offspring before dying earlier than their compadres.
- In the past these people would NOT have been able to pass on their deleterious mutations. Such mutations would have died with them, so populations in the past, because NATURAL SELECTION weeded out those with certain genetic disorders (none to few offspring), would have had few such genes.
- Now that modern technology has INTERFERED with NATURAL SELECTION, modern populations can be expected to exhibit more deleterious mutations because we can now use moderm medicine to nuture those who would have died before reproductive age.
- The consequence of any recent increase in the genetic load of disadvantageous mutations would be experienced IF we suddenly were bereft of the succor of modern technology (the "bomb with the long fuse" finally "explodes", so to speak).

What does this have to do with your religious (not scientific) notion of the "Fall" and resulting "Curse" ( great Guy, the OT God, of yours, dave, AKA the Cosmic Don or the ORIGINAL GODfather™ ). Are you going to claim that modern technology is the God's Agent of "the Curse" or what? But then the very introduction of the supernatural (a God who's into the ULTIMATE Whammy Business, e.g. "the Curse") makes your argument moot in a SCIENTIFIC discussion anyway (your evidence for the existence of your version of the Xtian God, Adam/Eve, teh "Curse" would be?). Crow's paper doesn't help you, or should I say Sanford's selective interpretation of this particular quote-mine you seem to have regurgitated without ~~gasp~~, dare I use it The "T" word, Thinking.

An additional point here is that Raup and many other evolutionists don't think that death/extinction are EVIL, but are simply necessary for both shaping and maintaining life as we know on this planet. Death actually is the engine that drives life on this planet. Without death, all of the nutrients/elements that make up living things would be never be recycled to generate new life. The fact is that life on this planet is the result of continual recycling of the basic elements which would be impossible without death which releases these elements back into the environment. Religions have taken advantage of the fact that what happens at death is unknown (for now) and humans have a tendency to fear the unknown. Christianity has exploited this fear by making death into some disease (part of "the Curse") for whom it promises a "cure" (hey believe and you'll live forever, "your-life-is-as-a-filthy-rag" schmuck!). No evidence is offered for such a thing as a life after this one and as Smith says "fortunately for Christianity, the dead cannot return for a refund".

Humans are almost certainly going to run afoul of that "absorbing boundary" one day (let's strive to make it later rather than sooner), no malicious, murderous, micromanaging egomaniac of a tribal-war god(s?) dreamed up by some oft-conquered (hence insecure), Bronze Age, Middle-Eastern goat-herding nomads need apply.

Pappy Jack · 06-24-2007, 01:16 AM

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Originally Posted by afdave

Amaleq ... May I ask something? Are you a geneticist? If not ... What is your area of specialty?

You're not a geneticist, Amaleq? Shame on you then for daring to question Dave's interpretation of genetic studies.

Oh, just a minute...... Are you a geneticist, Dave? Or an Egyptologist? Or a palaeontologist? Or an historian? Or an archaeologist? Or a specialist in any of the other areas that you post so knowledgably on?

Just what point were you trying to make with this question?

Pappy Jack · 06-24-2007, 01:17 AM

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Originally Posted by mfaber

.....Good evening, all (gladiatrix here from RD.net, my handle here on II is mfaber)! Thought I'd add my 2 centavos.....

Ave, gladiatrix! Awesome post, as expected.

Sven · 06-24-2007, 02:13 AM

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Originally Posted by Constant Mews

Whether at this point Dave is driven more by lack of intellectual capacity or sheer pig-headed stubbornness is an open question.

Don't you ask yourself this about almost every creationist?

Sven · 06-24-2007, 02:21 AM

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Originally Posted by afdave

Let me just add that I am not drawing this conclusion from Crow on my own. Dr. Sanford is a highly successful Cornell geneticist who renounced his evolutionary views because of information like this from Crow. If anyone likes I can quote him at length from his preface to prove this. Regarding this paper of Crow's he says ...

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Dr. Crow acknowledges the fundamental evolutionary problems created by the discovery of high mutation rates -- but tries to dismiss them using a very unrealistic theoretical model involving an artificial selection system based on "mutation count". (Whether of not this artificial selection scheme employs truncation or just quasi-truncation is just a matter of splitting hairs). He goes on to acknowledge that humanity must now be genetically inferior to our stone-age ancestors - an amazing confession about the reality of genomic deterioration. (Sanford, J.C., Genetic Entropy and the Mystery of the Genome, 2005, p. 171)

Interestingly, Sanford has (or pretends to have?) just the same misunderstanding as you. And this guy supposedly is a geneticist? It's hard to believe that he honestly misunderstands Crow!

I see that you claimed you'll contact Crow and ask. Please also ask him for permission to post his words here, I really fear that you paraphrasing him would let slip in the same errors again.

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06-23-2007, 08:32 PM	#332
deadman_932 Veteran Member Join Date: Jun 2007 Location: Altadena, California Posts: 3,271	Ever looked at insects in amber, Dave? How many generations do you think extant species underwent since their ancestors were captured in ...well, let's use Dominican amber. That would be a LOT more than the number of generations you say would cause extinction. You can't claim "bees would be long-lived in the post-diluvian world, so there would be fewer generations"... wait, I retract that... I bet you CAN actually say that, given your track record and utter ignorance of science.

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