Marty Pomeroy, advocate for anti-science

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A reader sent me a link to this horrid anti-evolution guest column in the MetroWest Daily News (I presume this is a suburban branch of the Boston Herald). It's appallingly bad, but so typical of the creationist strategy: fast and furious falsehood flinging, and the presumption no one will have the initiative or the ability to crosscheck the claims. It's also all stated in a pompous, self-satisfied style, as if the author knows more about biology than all those biologists out there…yet as becomes quickly obvious, the man knows nothing about genetics.

Well, I know a little about biology and genetics, and I'm willing to rip his dishonest essay apart, and there's always Mark Isaak's Index to Creationist Claims, which is a wonderful resource that makes it easy to tear into articles like this. It always surprises me, though, how unimaginative creationists are—it's always the same old bogus nonsense, repeated over and over again, with such oblivious confidence. Everything in Marty Pomeroy's essay has already been refuted.

Continue reading "Marty Pomeroy, advocate for anti-science" (on Pharyngula)

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Planned Ignorance from Abnormal Interests on May 27, 2005 10:24 PM

Yesterday PZ Myers demolished a "horrid anti-evolution guest column" on both Pharygula and The Panda's Thumb. PZ reproduces the entire article on his site. I just finished taking a look at it from my usual perspective. PZ shows that the... Read More

45 Comments

No! Not the ‘no beneficial mutations’ canard! Anything but that!

*sigh*

I do wish they’d come up with new arguments every now and then. Hearing the same old stupidity recycled endlessly is so mind-numbingly dull…

I do wish they’d come up with new arguments every now and then.

But then again, we are dealing with religious people, and religious people deal in doctrine. Doctrine is Truth; it does not change. Consider the battle between Answers In Genesis and Kent Hovind over creationist claims so obviously false that those making them (at least in AiG’s opinion) look either retarded or crooked. But Hovind refuses to discard these claims, because doctrine is the Rock Of Ages. It’s just another example of the eternal battle between certainty and correctness – you can have either one, but to get it you must accept the inverse of the other.

The real enemy of the creationist is not evolution, it is doubt.

The best response to this stuff is mild chiding and pointing towards preexisting refutations. If you want to write letters to the editor, I suggest saying something like

“Marty Pomeroy’s objections to evolution are typical of uneducated complaints against biology. Corrections can be found at http://www.talkorigins.org/indexcc/ .”

Pomeroy wrote:

Evolutionary theory proposes that there are two fundamental engines behind the advancement of species. The first engine is mutation, genetic change that can be passed on. This produces some difference in an organism that can be passed to its offspring, so the mutation must be present in reproductive cells.

The second engine is natural selection. This “selects” mutations that happen to be somehow “beneficial.” The next generation has statistically more of the “chosen” genetic material because the gene provides some reproductive advantage. So those creatures with this gene produce more offspring, whether because of more aggressive mating behavior, resistance to disease, longer life – anything that allows a species with this gene to reproduce more than those without it.

I don’t know what Pomeroy means by “evolutionary theory” and “fundamental engines behind the advancemet of species,” but genetic recombination and sexual reproduction were major causes of the existence of, and differences among, billions of organisms that have lived in earth. Every time organisms sexually reproduce, the offspring is different (in terms of genotype and phenotype) than its parents. I’m different from my parents. Every litter of puppies is different than its parents – even if they don’t have any new mutations. Genetic recombination and sexual reproduction were two of the most important kinds of events in terms of causing rodent-like mammals to evolve into gorillas. I suspect that most of the differences between chihuahuas and saint bernards were caused by genetic recombination, sexual reproduction and breading. Sexual reproduction has been a hugely important part of evolution. Different organisms sexually reproducing with each other is probably the principle cause of my being as different from Home erectus as I am.

According to Pomeroy:

In fact, there is no evidence for the existence of beneficial mutations in complex organisms.

That is not true. Here are some examples:

1. “In a stunning example of evolution at work, scientists have now found that changes in a single gene can produce major changes in the skeletal armor of fish living in the wild.”

Here is the link:

http://www.hhmi.org/news/kingsley4.html

2. “Researchers at the U.S. Department of Energy’s Lawrence Berkeley National Laboratory have discovered the mechanism by which an extremely rare protein mutation shields people from cardiovascular disease. The discovery could lead to more potent drug therapies that target both cholesterol deposition and prevent future accumulation. Results were reported in the February 12, 2002, issue of the journal Biochemistry.”

Here is a link:

http://www.science.doe.gov/Science_[…]Mutation.htm

3. “Where do new genes come from? Duplication, divergence, and exon shuffling are the expected answers, so it is especially exciting when new genes are cobbled together from DNA of no related function (or no function at all). In this issue, Chen et al. (1) describe an antifreeze glycoprotein (AFGP) gene in an Antarctic fish that has arisen (in part) from noncoding DNA.”

Here is a link:

http://www.pnas.org/cgi/content/full/94/8/3485

4. “By studying the green fluorescent protein in the great star coral, UF researchers were able to trace the evolutionary changes in individual genes that give rise to its complex diversity of colors. The results of the research, funded in part by the National Institutes of Health, will be published in the Sept. 3 issue of the journal Science.”

Here is a link:

http://www.napa.ufl.edu/2004news/co[…]volution.htm

5. Here is another interesting mutation, described by Sean Carroll in Endless Forms Most Beautiful:

“Examination of the gene-encoding MC1R of normal orange-phase jaguars and melanistic jaguars has revealed that a specific mutation exists in this gene exclusively in all black jaguars. This mutation deletes five amino acids and changes another amino acids in the MC1R protein. A cat that has one copy of the MC1R mutation and one copy of the normal MC1R gene is black; melanism is therefore said to be dominant. This means that the mutant form of the protein overrides the presence of the normal form. The change in the MC1R protein has caused it to be continuously active in stimulating eumelanin synthesis; it is blind to the presence of either hormones or inhibitors” (p. 230).

I’m sure being melanistic has been an advantage to some jaguars in terms of producing offspring. It might be harder for potential prey to detect you when you are hunting them in certain environments.

Finally, I think we should be careful not to attribute significant anatomical change between organisms to one single mutation. However, here is a link to an article on what some scientists think was an important mutation in terms of causing humans to be the way they are:

http://www.msnbc.msn.com/id/4593822

Finally, Pomeroy said:

Lastly, looking in the fossil record, you cannot show any two species that have come from a common ancestor.

I’m not sure what he mean by this. Nearly every known organism is very similar anatomically to at least one known organism that is older than it and relatively close in age to it. See, reptiles to early-mammals. Also, no known organism is very different anatomically than every known organism that is older than it. This traces back to bacteria that is about 3.5 billion years old.

However, the fossil data is not sufficient to determine that it is highly probable that self-replicating molecules evolved into all the organisms that have lived on earth. But that one piece of data is not sufficient to determine that an alleged event occurred does not mean that the event is no more plausible than not. For instance, scientists have a good idea about the age of the matter and space that we associate with the known universe. And their understanding of the speed of light helps them arrive at this reasonable inference. However, their understanding of the speed of light is not sufficient for them to arrive at this inference. Other data is needed, as well.

In the case of evolution, the fossil data is not the only relevant data available to us. The fossil data, along with other data, does enable us to determine that it is highly probable that self-replicating molecules evolved into all the organisms that have lived on earth.

Why did the newspaper publish the Op-Ed by Pomeroy? He’s not even a scientists. The editors should realize that he doesn’t understand the data as well as typical biologists do. This idea that we are obligated to present both sides of every issue is ridiculous. Should we publish Op-Eds on the theory of a flat-earth?

“Should we publish Op-Eds on the theory of a flat-earth?”

No. I agree with your reasoning. Sometimes, there really is one side to a story.

If one’s religion conflicts with science - change your religion.

You’re looking at this through a rather scientific viewpoint. But most people, who only vaguely understand science, see it this way–this guy has an opinion on evolution. It’s validity doesn’t matter–it’s an opinion, and just as good as the opinion of a man who has made it his lifework to study biology.

As you can doubtless guess, my respect for my species is perhaps somewhat lower than it should be…

So who the hell is Marty Pomeroy? What’s his interest in this, and what are his qualifications?

Scientists, please excuse my layperson lack of sophistication, but this is the response I wrote and submitted:

Marty Pomeroy’s opinion piece (“Rescue science from evolutionists” on 25 May 2005) is self-refuting. In the column, Mr. Pomeroy says, “The concept of natural selection has become so well established by the weight of evidence that anyone who would try to argue against it will be shown foolish. It is impossible to ignore the variation of species over geographical areas, and the recognition that these variations have become established as adaptations to their environment by natural selection.”

Mr. Pomeroy admits that natural selection is well-established and recognizes that variations are adapted to environments. Where does Mr. Pomeroy propose that this variation that is adapted to environments by natural selection comes from, if not from mutations? One possibility would be the discarded idea that acquired traits (a crushed toe, say) can get passed along to offspring. Another, I suppose, would be that each organism comes equipped with an endless “Swiss Army Knife” of genes that can be called upon, depending on environmental conditions. And still another would be that a “designer” would reach down every once in a while when some creature needed this or that and give their genetic make-up a little make-over. Pimp its ride, so to speak.

None of those possibilities seems even as remotely plausible as the observed, proven, and accepted fact that genetic variation from mutations provides the raw material natural selection then sifts to generate diversity within and among species.

Greg Peterson Minneapolis, MN

Good question Russell!

A quick Google search shows only that Marty has made at least one other appearance as a guest columnist.

To the surprise of nobody, the topic is (drum roll): GAY MARRIAGE.

Pomeroy: What does same sex marriage teach our children? By Marty Pomeroy / Guest Columnist Sunday, May 16, 2004

I’m a parent so I’m used to dealing in multi-dimensionals of gray. Is this album really that bad (some are)? Is that TV show with its innuendo and rudeness “over the line”? I try to get to “Yes” because I really care but I’m OK with saying …

As far as I can tell, you need to pay money to read the rest.

Since Marty is a creationist rube, I am going to guess that Marty also believes that same sex marriage somehow “teaches” “our” children things that Marty believes shouldn’t be taught to “our” children.

But we know, of course, that Marty is a script-reciting rube. If Marty cared at all about educating children, he would have analyzed that script for two seconds before he vomited it into the faces of Metro West readers. More likely, Marty is more concerned about what the scientific method “teaches” “our” children. Why is Marty concerned? Marty is concerned because his preacher told him to be concerned. Marty is a good follower of preachers.

Disturbingly, Marty’s slow-moving willfully ignorant brain is also allowed to come in contact with young soccer-playing children.

http://66.102.7.104/search?q=cache:[…]22&hl=en

You can imagine Marty, thinking deeply about how grass was so obviously designed for soccer coaches to stand on.

Feel free to write to Marty at [Enable javascript to see this email address.]. I’m sure he’d be happy to admit and correct the errors in his evolution article.

Right.

I was looking at his sickle cell anemia argument and wondering if his conclusions were supported in the cold, hard world of biological calculus. And while I’m not a doctor, a biologist or a scientist, but just an accountant who has only a reasonable familiarity with the issues, plus a series of B+’s and B’s in HS biology, I kind of got the impression that his argument was bogus. So I did a bit of research on the subject.

This “negative” mutuation he provides, sickle cell anemia, is also a beneficial mutation to persons living in tropical areas with high rates of malaria. This gene is, despite his assertion to the contrary, far far more beneficial to the projected survival of the inheritee than harmful as far as I can see. So, let me illustrate this:

Let’s take a populaion of 100 children born to individuals with a heterozygous copy the sickle cell anemia gene. Of this populuation of children, twenty-five percent won’t have a copy of the gene from either parent. They have no protection from malaria and are at high risk for malaria death. That’s not good.

Fifty-percent of the population will get one gene from one parent and none from the other. They are not at risk for sickle cell anemia, but, they get protection from malaria. The last twenty-five percent get a gene from both parents. This last group has a three-percent risk of developing sickle cell anemia. In this population, we will probably end up with one person who suffers sickle cell anemia and this person will most likely die a rather painful death in his, or her, 30’s or 40’s, after he’s passed on his/her genes.

Now, one person in 100 dying, versus the effects of malaria is typical of the way evolution acts. For the survival of the populaion, one death versus a substantially reduced death rate from a super-deadly disease like Malaria is the way to go. After all, better to lose one individual (after he/she fulfills his reproductive duties) than, even the huge population crashes a non-protected population would have. I don’t think Pomeroy knew that, even with some modern medicine, tropical countries frequently have fatality rates over fifty-percent in malaria out-breaks while even with a homozygous gene profile, the disease doesn’t express that frequently.

In this population, the twenty-five children with no protection will be hard-pressed to survive as an in-tact group to adult hood. Obviously some will live long enough to reproduce, but the 75 people with one or two copies of the gene will survive at a much higher rate, thus producing proportionally more offspring. At the cost of just one individual dying after substantially fulfulling his/her reproductive potential.

That Mr. Pomeroy is unaware of these issues, and picks sickle cell anemia of all things, to make a point that’s factually wrong illustrates the problem with Intelligent Design. Simply put, the promoters are ignorant of science, genetics and, frequently, even the high-school level biology I relied upon to illustrate just one of the many errors in his column.

He has also published a few letters to the MetroWest Daily News, as you can find here. All are behind the pay-per-view archive, unfortunately, but you can see enough to get an idea of his obsessions: god, gays, and evolution.

It would be nice if newspaper editors would at least do the work of fact-checking that being a responsible editor entails. My question is, if it was so easy for PT folk to find numerous refutations of the claims made by Pomeroy, why didn’t the editorial staff do a little bit of checking themselves? Perhaps, like our local paper here in Flagstaff AZ, the letter policy of the MetroWest News is completely open. All you have to do is submit a letter and it is published, barring certain obvious exceptions.

There is of course the possibility that the editors of MetroWest fear having a boycott of their publication by people of “faith”.

“As far as I can tell, you need to pay money to read the rest.”

you’re kidding! They couldn’t pay me enough money to bother.

Pomeroy wrote:

In fact, there is no evidence for the existence of beneficial mutations in complex organisms.

That’s a ridiculous statement. It is clear that mutations contributed to bacteria evolving into elephants. First, there is very good reason to believe that bacteria did evolve into elephants. Second, a significant percentage of cell-divisions have been followed by the daughter-cell having a genome that is different than the genome of its parent-cell. Humans average 1.6 new mutations per sexual generation among coding DNA. Bacteriophage M13 averages .0046 mutations per division. RNA-based lytic viruses average 1 new mutation per division. Third, genotype affects phenotype (observable traits). Finally, humans have maybe 25,000 coding genes. Mice probably have less, but not a lot less. And changes to a gene often affect the organism’s observable traits. Therefore, we have a huge correlation, namely common descent, frequently occurring mutations and a fairly small number of coding genes. We are justified in inferring that mutations played a significant role in baceria evolving into elephants. Especially because organisms with a mutation are sometimes fairly different than organisms with a nearly identical genome except they don’t have the mutation.

Now, there should be more work done on the causes of daughter-cells being different than their parent-cells.

It is interesting that meiosis always results in the daughter-cell being significantly different than the parent-cell. But scientists tend not to refer to meiosis as a “mutation.”

I do think some scientists tend to overemphasize the causal importance of mutation and underemphasize the causal importance of sexual reproduction. Most new mutations that we have observed didn’t cause the offspring to be significantly different than its parent(s). In contrast, sexual reproduction tends to result in much more significant differences from one organism to the next than mutations do. I probably don’t have new mutations that have significantly affected my phenotype. And I’m significantly different than my parents. I’m not an armadillo. But I’m significant different than my parents.

In fact, I tend to think mutations played a complementary role in rodent-like mammals evolving into gorillas – rather than the main causal role. I think genetic recombination, sexual reproduction and what Darwin called “natural selection” were the kinds of events that played the biggest role in mice evolving into gorillas. Remember, the body plan of mice and gorillas is very similar. Just look at their skeletons. One of the main difference is size. And chihuahuas are a lot smaller than saint bernards, and most of their differences were probably caused by sexual reproduction and breading. Remember, also, that recessive genes are really important in terms of bringing about traits.

George Mureson is a lot bigger than Mugsy Bogues. Mutations didn’t play a big role in that. But one or more mutations did affect their differences in skin color.

One interesting note is the existence of the first human with blue eyes was proximately caused by sexual reproduction and a new mutation.

Moreover, the combination of sexual reproduction plus a new mutation is the combination that we have observed producing the biggest difference between a parent and its offspring. This combination produces anomalies like the people who were exploited by being in circuses. It is this combination (sexual reproduction and mutation) that has caused achondroplasia (dwarfism). It has also produced fruit flies with four wings instead of two.

However, even in the case of sexual reproduction plus mutations, the difference between parent and offspring is never massive. Armadillos do not give birth to kangaroos. The elephant man is perhaps a kind of exception. Poor man.

Maybe Pomeroy’s point is that “beneficial new mutations” in complex organisms have never been observed by humans. But that’s not true. I gave some examples in my earlier post. Although beneficial new mutations to complex organisms are a small percentage of all of the mutations that humans have observed, that doesn’t mean evolution didn’t happen. Humans have been around a short time, a small percentage of all mutations have been “beneficial,” and the organisms that are alive today are very well-adapted – in most cases over millions of years.

Longhorn

I do think some scientists tend to overemphasize the causal importance of mutation and underemphasize the causal importance of sexual reproduction.

What percentage of the earth’s species reproduces sexually?

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Steve U. Wrote:

What percentage of the earth’s species reproduces sexually?

Too imprecise. Do you include all those who have any sort of sexual option? If so, then nearly all species reproduce sexually. Obligate asexuals seem to have a tendency to go extinct faster - except for the ones which don’t! If you mean only the obligate sexual reproductionists such as mammals, then by species (hard as that is to define at times) the mostly-cloners probably have the edge.

I was dismayed but not surprised to read the guest column by Marty Pomeroy (“Rescue science from evolutionists” on 25 May 2005). An uninformed and unimaginitive parroting of some of the great canards of creationism. He makes beating a dead horse seem positively fresh and exciting by comparison. Pomeroy’s ignorance of things scientific was breathtaking! Matched only by the arrogance of his tone. I await his devastating analysis of quantum mechanics and atomic theory.

Moses Wrote:

This “negative” mutuation he provides, sickle cell anemia, is also a beneficial mutation to persons living in tropical areas with high rates of malaria. This gene is, despite his assertion to the contrary, far far more beneficial to the projected survival of the inheritee than harmful as far as I can see.

Actually, there is an even more fundamental point here: there are some mutations (fatal, or reproduction-eliminating) that are innately detrimental to the organism. Virtually all other mutations are neither innately detrimental nor innately beneficial. The effect of the mutation on the chances for the organism to successfully reproduce are determined not only by the effect of the mutation, but by how well the new phenotype interacts with the environment.

Sickle cell is a perfect example of this - it is clearly beneficial in areas that have a high incidence of malaria and a low level of medical care. It is clearly detrimental in areas that have little to no risk of malaria. Albino mammals are another good example. A white-furred mouse rules in areas that are snow-covered for much of the year. But it’s screwed in areas that lack snow most of the time. Change the environment, change the effect of the mutation.

Flightlessness in insects is another example - a flightless insect may be at a disadvantage in an area where food is scarce, or where its species covers a wide geographic range. But on a small, windy island, the flightless bugs may have a better chance of reproducing because they don’t get blown out to sea. Change the environment, change the effect.

Steve U. posted:

What percentage of the earth’s species reproduces sexually?

Good point. I should have said among sexually reproducing organisms.

I posted:

I think genetic recombination, sexual reproduction and what Darwin called “natural selection” were the kinds of events that played the biggest role in mice evolving into gorillas.

That is not an ideal claim. It would have been better to say that genetic recombination, sexual reproduction and what Darwin called “natural selection” were the kinds of events that played the biggest role in rodent-like mammals evolving into gorillas. The youngest common ancestor that gorillas and mice share is probably best characterized as a rodent-like mammal rather than a mouse.

a little late, but i just wanted to note that the list of evolutionary biology articles Longhorm referenced was an interesting one. several studies i had not seen before.

thanks

it makes me wonder… where does one go to actually discuss the contents of articles like these, rather than the sociopolitical ramifications, or the obfuscations of the results presented by god-bothering tub thumpers?

No longer being directly involved in academia, one of the things i really miss are the meetings (usually just informal lunches) where we discussed the actual papers themselves; the methods used, the implications of the results from a scientific standpoint, etc.

cheers

Pomeroy has responded to PZ. See the comments section at Pharyngula.

Sir_Toejam Wrote:

where does one go … one of the things i really miss are the meetings

You could try sneaking back into academia! Otherwise you probably have to set up your own, heavily moderated, site and mention it in a few likely places. The BBC’s science board could only manage the occasional sane discussion of actual papers between troll attacks. However, even with a safe board, you can hardly force those still in academia to turn up when they have much easier venues (ones with food and drink too). Speaking of sites though, there was that call for Dmanisi suggestions …

Pomeroy has responded to PZ.

Has Pomeroy produced a scientific theory of ID and told us how to test it using the scientific method?

Why not?

No. He just posted to move the goalposts. I think it was a tacit acknowledgment that he was full of crap.

Pomeroy’s first argument at the Pharyngula site is that the “assumption” that God had no role is unnecessary.

This indicates once again that we need to repeat as often as necessary that science makes no such assumption. It is unfair, inaccurate, and stupid for anyone of faith to claim that anything that fails to mention God is somehow opposed to faith.

Mr. Pomeroy’s computer, automobile, television, and household plumbing all make this same “assumption,” if that is indeed what he claims it to be. Unless he’s fair and insists that he stop using his toilet until plumbing carries the same warning sticker, that the plumbing may actually be fairies who take the waste water away (or some other supernatural cause), he’s a bigot for picking on biology alone.

I wonder how the electricity in his house got there? There’s no mention of God and the chance that Zeus runs the utility, in the utility bill … maybe he should stop paying the utility bill in protest. That’s the ticket! Let’s encourage all creationists to stop paying their utility bills until the power company starts openly acknowledging that electricity might be from a supernatural source! Such a course of action on the part of creationist activists could produce huge benefits to education policy making.

Next: Boycott fossil fuels for Jesus.

Longhorm:

While I agree that genetic recombination in association with segregation and independent assortment produces substantial variation in gametes and offspring, sexual reproduction alone will not result in genetic change in a population absent any intervening evolutionary forces. All it will do is redistribute existing genetic variation in the population in proportions that are a function of the existing allele frequencies (i.e. H-W equilibrium). So while your point about the value of sexual reproduction to the diversity of offspring is well taken, it only contributes to evolutionary change when in concert with evolutionary forces such as selection, genetic drift, and mutation.

Let’s USE this evolution thing.

Start a movement among creationists to reject modern (read: satanic) medicine in favor of good old-fashioned faith-healing, laying on of hands, intercessory prayer, Bible-reading, demon-exorcising, etc.

The expected result: each generation, fewer creationists.

Possible complicating factor: abandoning modern birth control techniques and leaving family planning up to the “will of God” would likely result in extraordinarily high birth rates. In a world in which all modern medicine and public health measures were absent, creationists would be lucky to maintain their population level against infant mortality and diseases. But alas, godless science has made the world much safer even for those who reject all its satanic workings and refuse to vaccinate their kids. There just ain’t nowhere you can catch a good case of smallpox anymore.

Similar things do occasionally happen, Bob. Didn’t South Africa fall for Intelligent Design Medicine (Phil Johnson’s belief that HIV doesn’t cause AIDS) and ban incoming antiretroviral drugs for a while?

Pomeroy’s first argument at the Pharyngula site is that the “assumption” that God had no role is unnecessary.

This, remember, from the side that claims at every available opportunity (and will soon be testifying in court, under oath) that ID is SCIENCE and has NOTHIING to do with advancing religion. Nothing AT ALL.

This case will be SUCH a slam dunk . … . .

This indicates once again that we need to repeat as often as necessary that science makes no such assumption. It is unfair, inaccurate, and stupid for anyone of faith to claim that anything that fails to mention God is somehow opposed to faith.

Mr. Pomeroy’s computer, automobile, television, and household plumbing all make this same “assumption,” if that is indeed what he claims it to be. Unless he’s fair and insists that he stop using his toilet until plumbing carries the same warning sticker, that the plumbing may actually be fairies who take the waste water away (or some other supernatural cause), he’s a bigot for picking on biology alone.

Hence my oft-repeated-but-never-answered question to Sal about why “evolution” is any more “materialistic/naturalistic/atheistic” than is weather forecasting or accident investigation or medical practice.

Heddle also fled in terror from the very same question.

And I suspect FL will stammer and fall over it just like he did with Adam’s bacteria.

Apparently, for IDers, “atheism” is acceptable in some areas, but not in others.

Odd, isn’t it . … . .

Shaggy Maniac posted:

While I agree that genetic recombination in association with segregation and independent assortment produces substantial variation in gametes and offspring, sexual reproduction alone will not result in genetic change in a population absent any intervening evolutionary forces.  All it will do is redistribute existing genetic variation in the population in proportions that are a function of the existing allele frequencies (i.e. H-W equilibrium).  So while your point about the value of sexual reproduction to the diversity of offspring is well taken, it only contributes to evolutionary change when in concert with evolutionary forces such as selection, genetic drift, and mutation.

Shagggy, thanks for the post.

My point is that significant changes have occurred among some organisms without mutation being a major factor. So, I’m including “genetic drift” under my labels when I use the labels recombination, reproduction and natural selection. Part of the problem is the words. They mean different things to different people. We use words to label events. But my point is that some really significant changes were caused without mutation playing a significant role, or only a complementary role. My basis for saying this is the massive differences I see between some sexually reproducing organisms that were caused by (1) sexual reproduction and (2) some organisms producing the number of offspring they did. I’m think here about chihuahuas and saint bernards and extrapolating out 65 million years. Rodent-like mammals evolved into gorillas partly because some organisms produced the number of offspring that they did. There is no doubt about that. But I’m saying this combination of three kinds of events played a huge role in terms of causing rodent-like mammals to evolve into gorillas: 1. Recombination. 2. Sexual reproduction 3. What Darwin called “Natural Selection.”

What do you mean by “genetic drift?” In essence, you just mean sexual reproduction, right? I don’t use the expression “genetic drift,” because it has a vague meaning for a lot of people, especially for non-experts. And what do you mean by “genetic change in a population?” Sexual reproduction has resulted in “genetic change” between me and my parents. That is to say, I have a different genome than they do.

The key is that some organisms have sexually reproduced. And that process results in the existence of a significantly different genotype and phenotype. I’m an example of that. And I’m very different than my siblings, even though we all have the same parents.

The second key is that some organisms have, through sexual reproduction, produced more offspring than others. Just focus on those two kinds of events, and think of massive numbers of reproductive events, massive numbers of recessive genes and 65 million years. I’m sure that played a huge role in rodent-like mammals evolving into gorillas.

If you are saying that (1) sexual reproduction and (2) some organisms having produced the number of offspring they produced did not contribute massively to the differences between some organisms, why do you say that? We have a huge correlation. First, organisms have been reproducing on earth for maybe 700 million years – maybe 1 billion years. Second, it is clear the differences between chihuahuas and saint bernards were caused by sexual reproduction and breading, which is just another form of natural selection. Third, I’m quite different than my parents, and mutations don’t have anything to do with that. Fourth, beneficial mutations are a small percentage of all mutations. By “beneficial mutation” I mean a mutation that stays in a population for a long time and helps members of the population keep on reproducing.

Now some people say that mutations are what we observe adding knew genes. And that’s true. Gene duplication is a mutation, given how most people use those expressions. Perhaps recombination and reproduction (without any new mutations) varies the number of nucleotides sometimes. But not to the extent that gene duplications do. And it does look like differences in the number of coding genes does make a difference in terms of what organisms are like. Interestingly, the differences in numbers of genes are less than we thought. Humans and mice apparently have pretty similar numbers of genes – of coding genes.

Now mutation is what we often observe adding new matter to an organism. In other words, we have observed new mutation putting a new clump of matter somewhere on the organism. But recombination and reproduction can do that, too. At least if there are some recessive genes in there that get re-triggered. Or some genes that go from being non-coding to coding.

I think mutations played a large role in jelly-fish-like organisms evolving into humans. And I think mutations played a role in rodent-like mammals evolving into gorillas. Maybe a big role. But much of the difference between rodent-like mammals and gorillas was caused by genetic recombination, sexual reproduction, diet, the interaction between the organism and the environment (in the way Richard Lewontin talks about in Triple Helix), and what Darwin called “natural selection.” I can’t get over how different I an from my siblings, and mutation had nothing to do with that.

I posted:

Second, it is clear the differences between chihuahuas and saint bernards were caused by sexual reproduction and breading, which is just another form of natural selection.

I should say that much of the difference between chihuahuas and saint bernards was caused by genetic recombination, sexual reproduction and breading. I suspect that some of the difference between chihuahuas and saint bernards was caused by mutation. For instance, coat color.

I posted:

Fourth, beneficial mutations are a small percentage of all mutations.  By “beneficial mutation” I mean a mutation that stays in a population for a long time and helps members of the population keep on reproducing.

Let me change what I mean by “beneficial mutation.” I will mean any mutation that helps an organism reproduce. I still suspect that “beneficial mutations” have been a small percentage of all mutations. However, that might not be that important in terms whether we are justified in believing that significant changes between some organisms were not caused by mutations. For, think of what “small percentage” means. If only .2% of all mutations helped organisms reproduce, that would still be an enormous number of beneficial mutations. Organisms have been reproducing for about 3.8 billion years, and mutations are common events.

However, I think some significant changes occurred without mutations playing a significant role.

Start a movement among creationists to reject modern (read: satanic) medicine in favor of good old-fashioned faith-healing, laying on of hands, intercessory prayer, Bible-reading, demon-exorcising, etc.

The expected result: each generation, fewer creationists.

Let us most certainly not get them to reject modern medicine like vacinations. This would lead to widespread sickness, also among people who uses mdoern medicine, since herd immunity would be at risk. Also, I know from reading many science blogs, that there are quite a few with backgrounds in the Creationist camp, that have understod the errors of what they were taught in their youth. Future people like that, would be put at risk by their parents’ stupidity.

I wrote:

Now some people say that mutations are what we observe adding knew genes.  And that’s true.  Gene duplication is a mutation, given how most people use those expressions.

Gene duplications, chromosome duplications and duplications of the entire genome are kinds of mutations, given how must scientists use those words. These events result in increases in the number of nucleotides from one organism to the next. Differences in the number of nucleotides tends to affect phenotypes. And mutations clearly have contributed to the existence of new genes.

However, genetic recombination, sexual reproduction and natural selection may also have caused the existence of new genes. By “gene” I mean a sequence of nucleotides that plays a significant role in bringing about a given observable trait. I don’t know whether these kinds of events (without mutations) have ever brought about new genes. But I wouldn’t be surprised. We are talking massive lengths of time. Selection has contributed massively to the existence of, and differences among, most organisms. And the differences in genotype from one sexually reproducing organism to the next have often been fairly significant, for instance, I’m quite different than my parents.

According to Ernst Mayr, “Two processes during meiosis achieve a drastic recombination of the parental genotypes: (1) crossing-over during the first division and (2) the random movement of homologous chromosomes to different daughter-cells (gametes) during the reduction division. The result is the production of completely new combinations of the parental genes, all of them uniquely different genotypes. These, in turn, produce unique phenotypes, providing unlimited new material for the process of natural selection” (What Evolution Is, p. 104).

However, it is important to note that Mayr only describes the first part of sexual reproduction, namely the production of sex cells. There is whole additional part, the fertilization of the egg-cell with the sperm-cell. This results in the two sets of chromosomes sitting next to each other. They don’t blend. I think that none of the chromosomes even touch each other. In humans, the 23 chromosomes that the mother contributes sit next to the 23 that the father contributes. The cell then divides.

According to Mayr: “The process of sexual reproduction makes far more new phenotypes available for natural selection than does mutation of any other process. It is the major source of variation found in populations of sexual species.” I submit that sexual reproduction and natural selection brought about much of the difference between rodent-like mammals and gorillas.  

Longhorm:

You quoted Mayr: The result is the production of completely new combinations of the parental genes, all of them uniquely different genotypes. These, in turn, produce unique phenotypes, providing unlimited new material for the process of natural selection” (What Evolution Is, p. 104).

Here again, I agree that sexual reproduction is a powerful engine to produce genetic variation among offspring. The key part of the quote that is to my point is the last sentence. Natural selection still has to act on that genetic variation if there is going to be evolutionary change, i.e. changes in the allele frequencies in a given population over generational time. Evolution is a population level phenomenon. By generating variation among offspring, sexual reproduction may well affect the potential rate of evolutionary change in a population, but it does not cause the evolutionary change. Simply generating differences among offspring is not, in and of itself, evolutionary change.

Longhorm:

You quoted Mayr: The result is the production of completely new combinations of the parental genes, all of them uniquely different genotypes. These, in turn, produce unique phenotypes, providing unlimited new material for the process of natural selection” (What Evolution Is, p. 104).

Here again, I agree that sexual reproduction is a powerful engine to produce genetic variation among offspring. The key part of the quote that is to my point is the last sentence. Natural selection still has to act on that genetic variation if there is going to be evolutionary change, i.e. changes in the allele frequencies in a given population over generational time. Evolution is a population level phenomenon. By generating variation among offspring, sexual reproduction may well affect the potential rate of evolutionary change in a population, but it does not cause the evolutionary change. Simply generating differences among offspring is not, in and of itself, evolutionary change.

Sorry for the double-post.

Here again, I agree that sexual reproduction is a powerful engine to produce genetic variation among offspring.  The key part of the quote that is to my point is the last sentence.  Natural selection still has to act on that genetic variation if there is going to be evolutionary change, i.e. changes in the allele frequencies in a given population over generational time.  Evolution is a population level phenomenon.  By generating variation among offspring, sexual reproduction may well affect the potential rate of evolutionary change in a population, but it does not cause the evolutionary change.  Simply generating differences among offspring is not, in and of itself, evolutionary change.

Shaggy, how are you using the term “evolutionary change?” And what evidence is there that “sexual reproduction [along with genetic recombination and natural selection] does not cause evolutionary change?” Are you saying that genetic recombination and sexual reproduction did not contribute significantly to the the differences between rodent-like mammals and gorillas? If so, I disagree. Also, you have not offered any evidence.

It may be that (1) genetic recombination, (2) sexual reproduction and (3) natural selection did not by themselves cause some organisms to be significantly different than their descendants. Even that I wonder about. But there is very good reason to believe that these three factors together brought about some of the significant difference between some organisms. I realize causation is complicated.

I think you are saying that mutation and natural selection caused all of the difference – or at least all of the “important difference” – between all organisms. And I don’t agree with that. But if you make your case, I’ll listen to you.

Given how I think you are using the phrase “changes in the allele frequencies in a given population over generational time,” I think (1) Genetic recombination, (2) sexual reproduction and (3) some organisms producing the number of offspring that they produced has “changed the allele frequencies in a given population over generational time.” How are you using the phrase “changes in the allele frequencies in a given population over generational time?”

Let me make my point really cut and dry: (1) Genetic recombination, (2) sexual reproduction and (3) some organisms producing the number of offspring that they produced contributed significantly to the existence of, and differences among, some organisms. I offered data in my previous posts that I think supports this claim.

These three factors helped rodent-like mammals evolve into gorillas. I’m sure you agree with that. What you might be saying is that genetic recombination and sexual reproduction did not cause much of the difference between rodent-like mammals and gorillas. In other words, you may be saying that, although these three factors helped evolution happen, they didn’t by themselves cause any of he difference between any organisms. But I strongly disagree. First, I’m different than my parents. Quite different. And mutation has nothing (or very little) to do with that. Second, extrapolate out 700 million years the differences between me an my parents. Add in dietary factors. And natural selection.

Also, what evidence do you have? It is hard to prove a negative. I have huge a correlation on my side, namley (1) organisms having been reproducing at very high rates on earth for between 1.5 billion and 700 million years, (2) much of the difference between me and my parents was caused genetic recombination and sexual reproduction and (3) much of the difference between chihuahuas and saint bernards was caused by genetic recombination, sexual reproduction and breading.

Mutations also helped rodent-like mammals evolve into gorillas. But I submit that the three factors I mentioned mattered a lot in rodent-like mammals being as different from gorillas as they are.

Longhorm,

You seem to be intent on conflating natural selection with sexual reproduction. You wrote:

“Let me make my point really cut and dry: (1) Genetic recombination, (2) sexual reproduction and (3) some organisms producing the number of offspring that they produced contributed significantly to the existence of, and differences among, some organisms.”

Parts 1 and 2 of your point are part of sexual reproduction. Recombination is a meiotic event so that we can consider it part of sexual reproduction. By “sexual reproduction” in part 2, I assume you are referring to the randomness involved in combining gametes. Note, we’ve also got independent assortment as part of gamete formation. Yes, again, these processes generate a great deal of genetic variation among offspring in sexually reproducing populations. But, given a set of allele frequencies in a hypothetical population, none of those processes will result in changes to those allele frequencies over time under the standard assumptions of Hardy-Weinberg equilibrium, i.e. large population size, random mating, no mutations, no migration, NO selection.

Your point part 3 is selection, i.e. differences among the offspring in survival and reproductive success. But this has nothing to do with sexual reproduction itself. If among the variety of offspring produced by sexual reproduction in a given generation there is no difference in survival and reproductive success, then there is no cause for the allele frequencies of the population to be any different in the subsequent generation(s). Sexual reproduction can keep reshuffling the genomes of the individuals of the population as a function of the starting allele frequencies, but the gene pool (the relevant object of evolution) will not change due to the mixing processes of sexual reproduction.

Note, I am acknowledging that sexual reproduction effectively gives natural selection more to potentially work with in any given generation than would be present in an asexual population, but sexual reproduction in and of itself is not an agent of evolutionary change. This is really a just a basic concept in population genetics.

Parts 1 and 2 of your point are part of sexual reproduction.

I understand that.

Recombination is a meiotic event so that we can consider it part of sexual reproduction.

Some people are using the phrase “recombination” to refer to the creation of sex cell and only to the creation of sex cells. Others are using it to refer to both the creation of sex cells and the actual fertilization event. Also, the creation of sex cells does, by itself, result in genetic diversity. That is why I broke it down and mentioned both. But I don’t want to get bogged down on that.

Maybe I’m not making my point clear enough. My point is that the combination of sexual reproduction and some organisms having produced the number of offspring that they did contributed significantly to the existence of, and differences among, some organisms. For instance, it helped cause humans and rodents to be as different as they are.

But, given a set of allele frequencies in a hypothetical population, none of those processes will result in changes to those allele frequencies over time under the standard assumptions of Hardy-Weinberg equilibrium, i.e. large population size, random mating, no mutations, no migration, NO selection.

I don’t see your point.

Your point part 3 is selection, i.e. differences among the offspring in survival and reproductive success.  But this has nothing to do with sexual reproduction itself.

My point is that the combination of sexual reproduction and some organisms having produced the number of offspring that they did contributed significantly to the existence of, and differences among, some organisms. 

Sexual reproduction can keep reshuffling the genomes of the individuals of the population as a function of the starting allele frequencies, but the gene pool (the relevant object of evolution) will not change due to the mixing processes of sexual reproduction.

What do you mean by “the gene pool?” And what evidence do you have for that?

Also, sexual reproduction isn’t just a “reshuffling,” given how I think you are using that term. The creation of sex cells can reasonably be called a “reshuffling,” though there is also a reduction in the number of chromosomes. However, sexual reproduction puts the two chromosome sets next to each other. That is more than reshuffling, as in reshuffling the same deck of cards.

Note, I am acknowledging that sexual reproduction effectively gives natural selection more to potentially work with in any given generation than would be present in an asexual population, but sexual reproduction in and of itself is not an agent of evolutionary change.

What do you mean by “evolutionary change?” Of course, my parents reproducing did not cause the existence of an organisms that is massively different than them. I’m not an armadillo. But the combination of sexual reproduction and some organisms producing the number of offspring they did played huge roles in bringing about the differences between rodent-like mammals and humans. Of course sexual reproduction and natural selection enabled jeffly-fish like organisms to evolve into humans. Had sexual reproduction not evolved, something as complex as humans probably would not have evolved. Except on Star Trek.

Longhorm:

To some extent, I think we are speaking past one another. Let me reiterate that I recognize the important role sexual reproduction plays in both generating diverse gametes and in bringing together new combinations of genes among offspring. Compared to a strictly asexual system of reproduction, sexual reproduction certainly plays a significant role in making new combinations of genes available for selection to act upon. If there are fitness (survival and reproductive success) differences among the offspring that result, you could be in a limited sense correct in asserting that sexual reproduction played a role in evolution by producing the more fit new combination of genes. Indeed, this may be an important part of why sexual reproduction is so widespread across diverse groups of organisms. I get the fact that sexual reproduction produces new genetic combinations.

The point I have been laboring to make is that you can make the above statement about the role of sexual reproduction in evolution only if there are fitness differences among the offspring. If all of the offspring, though diverse, are equally likely to survive and reproduce, they will simply contribute genes to the next generation in proportions that already exist. Keep in mind I am focusing on the contribution of alleles to the next generation averaged over the entire population. Here is the key - the standard population genetic definition of evolution is an observed change in allele frequencies over generational time. In the absense of fitness differences among the offspring (i.e. the absense of selection), sexual reproduction by itself only functions to redistribute alleles among offspring (individuals) without any resulting change in population allele frequencies.

The fact that you are different from your parents and siblings is relevant to evolution only if you or one of your siblings is effectively more fit in a given environment than other individuals in the population.

Shaggy, I appreciate your taking the time to respond. It might be good to continue this conversation. Maybe it would make sense to talk on the phone.

Here is my point:

Lage populations of organisms sexually reproducing over tens of thousands – or millions – of years is one of the main causes of some organisms being as different from other organisms as they are. For instance, rodents and gorillas. I’ve presented data in this thread. Maybe I can get into more detail later.

Maybe your point is that large populations of organisms sexually reproducing over tens of thousands – or millions – of years did not cause the difference by itself. Well, maybe not. I’m not sure. But it definitely played a role.

The point I have been laboring to make is that you can make the above statement about the role of sexual reproduction in evolution only if there are fitness differences among the offspring.

I’m not sure how your point is related to my hypothesis. But sexual reproduction does cause “fitness differences among offspring.” Some siblings are more fit than others – without mutations mattering.

More importantly, some organisms sexually produced more offspring than others. Over long periods of time, this made a difference in terms of offspring being the way they are. Also, keep in mind that we are talking massive lengths of time. Look at how different chihuahuas are from Saint Bernards. Most of that was caused by different dogs sexually reproducing with each other. Saint Bernards are more “fit” than chihuahuas in certain contexts.

Maybe your point is that large populations of organisms sexually reproducing over long periods of time did not cause any of the significant different among organisms. Why do you say that? You haven’t offered any data. I realize it is difficult. You may be trying to prove a negative.

Maybe this is the data you would use to support your conclusion:

No person has observed sexual reproduction causing one organism to be “very different” than another. Well, maybe you right. Maybe chihuahuas and saint bernards aren’t very different. Or maybe all those important differences were caused by mutations. But it is not necessary to have a person observe an event to be justified in believing that it occurred. No person saw planet earth exist 65 million years ago, and I’m sure it existed then.

Doesn’t recombination just rearrange alleles that are already there? There’s bound to be some limit on how much variation can be produced by rearrangement of already existing alleles, though I’ve no idea what that limit is.

If the breeding eliminates some alleles from the resulting population, might that put a limit on breeding in some particular direction (i.e., with certain features as the goal)? What I’m thinking is that once all the alleles that push things in the wanted direction have been “found”, that might be that. (Might that be why breeding for larger size can only get so far and no farther?)

Henry

Henry:

What you are rightly referring to is the limit on additive genetic variance that might exist in a given population. Without new mutations, eventually all the existing variation for a given trait could play out in a population under directional selection. Longhorms examples of dog breeds illustrates that there is a great deal of variance on which selection (selective breeding, in this case) can act, but it does have limits and contravening constraints. In terms of my discussion with Longhorm in this thread, the existence of genetic variance in the population is only relevant to evolution when there is some selective agent acting on it. Otherwise, as you indicate, sexual reproduction will just keep redistributing the alleles at current levels of variance/in existing proportions and there will be no evolutionary change.

Shaggy

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This page contains a single entry by PZ Myers published on May 26, 2005 1:31 PM.

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