Just when you thought it was safe to go in the water again …

| 59 Comments

… another shark appears, begging to be jumped.

One of Ray Comfort’s favorite examples of the invalidity of evolution (besides the banana) is sex. A while back Comfort objected to critical remarks about his book by PZ Myers. Comfort is quoted as saying

“Let’s go back even further (100 million years ago) to pre-pre-elephants that also contained males and females. At what point of time in evolutionary history did the female evolve alongside the male? And why did she evolve? Then explain, if you would professor, why horses, giraffes, cattle, zebras, leopards, primates, antelopes, pigs, dogs, sheep, fish, goats, mice, squirrels, whales, chickens, dinosaurs, beavers, cats, human beings and rats also evolved with a female, at some point of time in evolutionary history. Professor, I know you believe, but please, give us who are healthy skeptics some empirical evidence. Remember, stupid people like me want good hard evidence before we, like you, become believers in Darwin’s theory,” Comfort said.

In other words, if evolution is true who were Cain and Abel canoodling with? Erm, sorry about that. Wrong story line. PZ then smacked Ray around in more detail here. Comfort’s remarks are at the level of the old creationist question, “If we evolved from monkeys how come there are still monkeys?”

However, intelligent design, we are told, is not creationism and is a much more sophisticated and ‘scientific’ enterprise. Or is it? On Uncommonly Dense, William Dembski’s group blog, we find this gem in a post by “niwrad”::

It is unimaginable that reproduction and genitals arose by Darwinian evolution (that is for random mutations and natural selection). First, as a matter of principle: evolution needs reproduction; without reproduction no evolution. Therefore how can reproduction be the effect of evolution if evolution is an effect of reproduction? It’s an impossible causality inversion. Second, for a technical reason: how could the male organs arise independently from the female organs given the cCSI they share? In fact the Darwinian processes work in the single individual. They are blind and unaware of the processes running in other individuals. Random mutations that happen in a genome have nothing to do with the mutations in another one.

”.… Darwinian processes work in the single individual”? It’s hard to conceive of the level of ignorance necessary to make the argument in that post. Apparently the notion of “coevolution” is foreign to the UD poster. But then, it only yields 186,000 hits on Google Scholar.

It’s fun to see UD in bed with Ray Comfort. Somehow I think they were made for each other. And I don’t think it was coevolution: It’s a straight lineage, ancestor to descendant.

59 Comments

I was bemused a few months ago with an item claiming that a certain fish fossil showed the first sign of sex (I was under the impression that sexual reproduction existed for at least hundreds of million years before then) until I realised that what was meant was internal fertilisation. There are many ways of achieving sexual reproduction, including male and female corals just simply releasing their gametes into the ocean at the same time.

Jesus Ray, what about all those hermaphrodite animals, worms and such; where do they fit in to your absurd world. Oh yeah and the sterile mule offspring of a horse and donkey, what was god thinking there?

They’re kissing cousins, I think…

UD is definitely moving towards explicit creationism: I guess Barry Arrington doesn’t worry about making the distinction between the two any more.

(the distinction being one of appearance, rather than substance BTW)

OMg, just found out by wiki that Comfort is an NZer, damn!

I would like to apologize to all PTers for this, and I would just like to let you know that our church attendance is marvellously low, and that our schools are religiously a-religious: Cheers:)

Chicken! No, egg! Umm, no, wait.. chicken! Hang on.. hehe, almost caught me… egg of course! Who laid.. what? Oh.. chicken! No, that can’t be right. Egg! Boy, this biology stuff sure is complicated! What does the bible say?

slang said:Boy, this biology stuff sure is complicated! What does the bible say?

Striped poles.

rossum

Once again, true to form, creationists absolutely ignore any and all comparative evidence.

Reproduction is a primary charcteristic of all life forms, it evolved with the first living things. Sexual reproduction is as old as bacteria since, in one form or another, they possess many pseudo sexual processes. Sexual dimorphism and the evolution of mating types is as old as protists. Gametes and fertilization are at least as old as animals, with many different types of external and internal fertilization and anisogamy is almost as old. This “which came first the egg or the sperm” routine is getting pretty tired.

And of course, let’s not forget that the main advantage of sex is to increase the genetic variation on which natural selection can act. I wonder how creationists explain the very existence of sexual reproduction at all? Oh well, if you are going to ignore all of zoology and comparative biology, you might as well ignore all of genetics and evolutionary biology as well.

Richard B. Hoppe said: Apparently the notion of “coevolution” is foreign to the UD poster.

Oh, good - you saw my comment (#1), which starts “In the world of actual science, the topic of “coupled complex specified information” is covered under the heading of “coevolution.”” In all fairness, other commenters also thought niwrad’s posting was a joke or otherwise incompetent.

Many posters (and commenters) at Uncommon Dissent are more or less scientifically illiterate, and more of us should spend time in their playground, yanking them around. Dembski encourages cross-cultural fertilization - so should we.

niwrad wrote:

“In fact the Darwinian processes work in the single individual. They are blind and unaware of the processes running in other individuals. Random mutations that happen in a genome have nothing to do with the mutations in another one.”

Um, the topic was sexual reproduction remember. Are you saying that no individual can pass on genes to any other individuals? Are you saying that genes cannot be passed from male to female or female to male? Are you saying that mutations that occur in two different individuals cannot be combined into a single individual?

Are you saying that individuals evolve and not populations? Are you saying that if they were “aware” of the “processes running in other individuals” that they could choose to evolve in a certain way?

Man, these guys find whole new fields of biology to ignore every day, it must be exhausting. It’s unimaginable that anyone could be so ignorant.

DS: I think that is exactly what they are doing. Remember, to them “evolution” is not the slow accumulation of very small changes passed from one generation to the next over long periods of time. If they even bother to acknowledge the possibility (as opposed to the notion of a species being “fixed for all time”), that’s what they would describe as “micro-evolution”. To them, “evolution” (in the sense of a speciation “event”) is massive (dare I say “miraculous”) changes occurring within a single individual within their lifetime, so that a dog gives birth to a cat. It is “obvious” to them that the first cat-from-dog had to be one of the two cat-from-dog sexes (and God made “man” first, so it’s “obviously” the male cat-from-dog). Then, “obviously” the first cat-from-dog would need another cat-from-dog of the opposite sex in order to continue the new species. No second miracle, and the poor lonely cat-from-dog dies without continuing his species. Remember, this is exactly what the Bible says happened in the Garden: miracle : man : lonely : second miracle : woman : new-species. I think this is where they have that mental block between micro-evolution and macro-evolution. In their minds, the two are just completely different classes of events.

More to the point, we see in today’s media examples of isolated cat-from-dog all the time. Well, sort of. :-) There are pictures of two headed snakes and six legged frogs all the time. There was one of those medical miracle TV shows earlier this year about a two-headed girl, and how she was succeeding in life and baseball, despite the odds against her. Here was a concrete example of massive morphological change in a single generation. I.E., “macro-evolution”. Obviously for there to be a viable species of two-headed humans, this young girl would have to find a contemporaneous two-headed boy with whom to mate. No, mate? Then, no two-headed-human species. And if even that “minor” morphological change is way too implausible, then cat-from-dog is obviously impossible. Therefore, God.

At least, this certainly seems to be the creationist’s misunderstanding of what “macro-evolution” is.

Paul Burnett said:

Richard B. Hoppe said: Apparently the notion of “coevolution” is foreign to the UD poster.

Oh, good - you saw my comment (#1), which starts “In the world of actual science, the topic of “coupled complex specified information” is covered under the heading of “coevolution.”” In all fairness, other commenters also thought niwrad’s posting was a joke or otherwise incompetent.

I actually didn’t read any of the comments there before I wrote this, but it’s excellent that you made the same point there.

Scott,

You are probably right. However, no sane person would believe that evolution could work that way. Why on earth would someone misrepresent the real science so badly? And if they really are that ignorant of modern evolutionary theory, why do they think that they know better than the experts? Why can’t they at least try to educate themselves before displaying their ignorance?

The argument “I’m too lazy to learn anything” isn’t going to convince anyone who isn’t equally lazy. This is comparable with arguing that the tooth fairy must exist since the Bible clearly states an eye for an eye and a tooth for a tooth, so a quarter for a tooth seems reasonable as well!

DS said:

Scott,

You are probably right. However, no sane person would believe that evolution could work that way.

Don’t underestimate the power of people who are determined to remain stupider than rocks for the sake of piety.

Why on earth would someone misrepresent the real science so badly?

Because someone told them that God told them to do so

And if they really are that ignorant of modern evolutionary theory, why do they think that they know better than the experts?

Again, don’t underestimate people who think that ignorance is a blessed virtue. People like Ray Comfort or Ken Ham or Kirk Cameron think that, because they think the (King James’ translation of) the Bible is literally, word for word true and accurate, they therefore know better than those evil, Pagan, devil-worshiping, materialistic scientists.

Why can’t they at least try to educate themselves before displaying their ignorance?

Because, to them, actually attempting to learn about the world without their Bible-blinders is a mortal sin: they risk entangling their immortal soul with the world if they dare to study it.

The argument “I’m too lazy to learn anything” isn’t going to convince anyone who isn’t equally lazy. This is comparable with arguing that the tooth fairy must exist since the Bible clearly states an eye for an eye and a tooth for a tooth, so a quarter for a tooth seems reasonable as well!

Well, if so many people think that the Bible is such a trustworthy source, then how come none of the Christian politicians have attempted to pass laws outlawing the pork or polyester industries, or make unruly children a crime punishable by death?

Does it strike anyone that “niwra[D]” is probably a Poe?

Wheels,

Let’s hope so. Otherwise his mama will have to have a talk with him about the birds anfd the bees and phylogenetics.

DS said: Why on earth would someone misrepresent the real science so badly? And if they really are that ignorant of modern evolutionary theory, why do they think that they know better than the experts?

I think maybe because the “evidence” that one can “see” with one’s own eyes is that “mutations” are always bad; dramatic morphological changes can occur in a single generation, and they’re “always” detrimental. Not only does it say so in the Bible, it’s the “obvious” evidence of everyday life. This is the everyday experience that people have with “change over time”. The actual evidence of evolution and billions of years is just not visible or even comprehensible to the average Joe Six Pack. How can scientists be right when what they say is contradicted by what Joe can see with his own eyes? How can Joe trust scientists when their story keeps changing, when they don’t agree, when they use wishy washy language, and admit themselves that they don’t know for sure? Remember, 30% of people in Los Angeles fail out of high school. Scary.

So, on the one hand Joe has scientists he doesn’t trust using the language of uncertainty to describe things that are visibly “wrong”, and on the other Joe has evangelists he wants to believe using the language of absolute certainty to describe a world that Joe can “see”. It’s depressingly not hard to understand why Joe thinks he knows better than the experts.

I don’t know how accurately these are quoted, but pithy sayings sometimes ring true. http://aceonlineschools.com/35-thou[…]tion-quotes/

Wheels said:

Does it strike anyone that “niwra[D]” is probably a Poe?

Looking at the link provided in the UD OP, which appears to be by the same guy, I don’t think it’s a Poe. I think it’s real, or as much as that level of abject ignorance can be real.

I just noticed this part of the comment:

Random mutations that happen in a genome have nothing to do with the mutations in another one.

In the context of niwrad’s discussion of the evolution of male and female genitalia one has to wonder if niwrad knows that males and females are the same species and share a genome.

aferensis,

It’s even worse that that. One of the most important advantages of sexual reproduction is exactly what this guy is denying, the ability to combine mutations occuring in two different individuals into one genome. So his argument basically boils down to, if sex doesn’t do what it actually does, how could it evolve? Brilliant!

Chicken! No, egg! Umm, no, wait.. chicken! Hang on.. hehe, almost caught me… egg of course! Who laid.. what? Oh.. chicken! No, that can’t be right. Egg! Boy, this biology stuff sure is complicated! What does the bible say?

There’s a yolk in there someplace?

what about all those hermaphrodite animals, worms and such; where do they fit in to your absurd world.

Snails are perverts, so they don’t count.

At what point of time in evolutionary history did the female evolve alongside the male? And why did she evolve?

This guy thinks males are more important than females? That gives the impression that he doesn’t know which gender lays the eggs. (Some species do that without male involvement.)

First, as a matter of principle: evolution needs reproduction; without reproduction no evolution. Therefore how can reproduction be the effect of evolution if evolution is an effect of reproduction?

Well, I’m no biologist, but my guess is that asexual reproduction came first (fission or cloning, perhaps), and sexual reproduction evolved as a secondary reproductive mechanism within a primarily asexual species. (Aren’t there species today that possess more than one mechanism of reproduction?)

Henry

Henry wrote:

“Aren’t there species today that possess more than one mechanism of reproduction?”

Of course. Cyclic parthenogenesis is just one example. Many parasites and plants have both asexual and sexual types of reproduction as well. As I mentioned, you have to ignore almost every living thing to make such a nonsensical argument. But then again, what can you expect form someone who thinks that there are only one thousand species that are only 6000 years old?

From now on the answer to that eternal question should be “The Chickegg”. It kills two birds with one stone, sort of…

I was glad to see this pop up again. I thought Ray the Banana Man got an epic spanking by PZ with his ‘where did girls come from then.. huh!?!? huh!?!?’ stupidity. PZ’s answer was so good (I learned a ton from it and I suspect most without a formal science background could agree with me there) that whatever shred of intellectual compassion I had for Comfort evaporated. If he (Ray) actually read that answer and did not apologize profusely for even asking the question, that makes him either an idiot or just another liar for Jesus. Not a lot of middle ground.

Everybody know males and females are separate species! – ask any woman –

I found a female dragonfly waiting on a male, hoping to see the mating. A male came, but I couldn’t follow their flight.

Explain how this came to evolve:

http://www.e-picworld.com/2009/06/d[…]-mating.html

veritas36 said:

Everybody know males and females are separate species! – ask any woman –

Therefore, since kind should mate with like-kind, men should mate with men! I knew it all along.

veritas36 said:

Explain how this came to evolve:

http://www.e-picworld.com/2009/06/d[…]-mating.html

Barry White. Oh yeah, baby.

veritas36 wrote:

“Explain how this came to evolve:”

Actually that one is fairly easy. Dragonflies generally mate in flight, probably to avoid predation. The male genitalia are modified into claspers in order to grip the female securely behind the head in order to remain coupled in flight. This is a fairly straight forward modification with obvious adaptive significance. The male genitalia are thus not used to transfer sperm to the female, instead the male transfers the sperm to a special sperm storage structure in the thorax. The female then transfers the sperm from the sperm storage structure using her genitalia. There is most likely an adaptive significance to this type of mating, however this organ is unique in the insect world.

I’m sure thee are lots of studies on exactly how such a system could evolve, if you are interested in that pathetic level of detail. Suffice it to say that it is just one of the many unique and facinating variations on a theme that makes the world of insects so remarkable and so enjoyable to study.

Oops, the sperm storage device is actually located on the underside of the second and third abdominal segments. My bad.

Randy said:

I was glad to see this pop up again. I thought Ray the Banana Man got an epic spanking by PZ with his ‘where did girls come from then.. huh!?!? huh!?!?’ stupidity. PZ’s answer was so good (I learned a ton from it and I suspect most without a formal science background could agree with me there) that whatever shred of intellectual compassion I had for Comfort evaporated. If he (Ray) actually read that answer and did not apologize profusely for even asking the question, that makes him either an idiot or just another liar for Jesus. Not a lot of middle ground.

I never got to hear Comfort’s sexual mis(heh)conceptions, nor subsequently PZ’s tearing down of them. What did it for me was the banana thing. He forgets that God’s banana is much less perfectly designed for eating than the artificially-selected Cavendish cultivar.

Bob O H Wrote:

UD is definitely moving towards explicit creationism:

That’s if you look at only one end of the big tent, as ~99% of us critics do. After Dover they have little to lose by more explicit pandering to YECs and OECs. Yet at the other end they keep conceding more of the details to evolution, as evidenced by Behe’s further retreat in “Edge of Evolution”, the gradual abandonment of “scientific” arguments against evolution in favor of the “Darwinism leads to Nazism” angle, Dembski’s admission that the “design” could have been front-loaded into the universe (not even Earth’s first cell, as Behe suggested), etc.

Of course IDers will not admit to either.

Henry J said:

Chicken! No, egg! Umm, no, wait.. chicken! Hang on.. hehe, almost caught me… egg of course! Who laid.. what? Oh.. chicken! No, that can’t be right. Egg! Boy, this biology stuff sure is complicated! What does the bible say?

There’s a yolk in there someplace?

what about all those hermaphrodite animals, worms and such; where do they fit in to your absurd world.

Snails are perverts, so they don’t count.

Don’t even get me started on the Moties.

http://en.wikipedia.org/wiki/The_Mote_in_God’s_Eye#Moties

The link in the above post terminated at the apostrophe. You’ll need to copy and paste it you you don’t know what a Motie is.

haha,you guys are very cute

sounds interesting

Henry J said:

Well, I’m no biologist, but my guess is that asexual reproduction came first (fission or cloning, perhaps), and sexual reproduction evolved as a secondary reproductive mechanism within a primarily asexual species.

i mean, i know they don’t want to play along here, and didn’t pay ANY attention in high school biology, but… they really haven’t heard of asexual reproduction?

(Aren’t there species today that possess more than one mechanism of reproduction?)

yes! sea stars, for one.

It’s an impossible causality inversion.

“Impossible causality inversion.” Gotta love that! It’s the next big information theoretic conceptualization from the Dembski crew: ICI. Evolution cannot be an explanation where ICI is present, thus it is necessary to explain it with design.

Sex defined as genetic exchange is very old, predating the eukaryotes. Prokaryotes have a variety of methods of genetic exchange, plasmid mediated conjugation with “males” and “females”, transformation by naked DNA, and phage mediated transduction. One can do all three with E. coli.

The reason for sex is thought to be to facilitate evolution by reassorting alleles. The other reason is to escape Mueller’s ratchet. By exchanging genes, they can keep deleterious mutations from accumulating.

Few organisms are exclusively parthenogenic and they are thought to be dead ends. The Bdelloid rotifers were thought to be asexual. Recently by sequencing it has been shown that they do exchange genes by a weird way.

The big innovations of the eukaryotes were the diploid genome and meiosis.

Even if one believes that random chance created males & females, doesn’t thinking about the teleological meaning of sexual organs (reproduction) undermine the religion of evolutionism? Evolutionism teaches that teleology doesn’t exist so that the mouth, anus or any hole in the wall is a proper sex organ. I wonder if PZ Myers or any other evolutionist could tell me a species that reproduced itself using the kind of sexuality found in prisons, San Francisco bathhouses, or other evolutionist meeting places.

Toidel Mahoney, are you for real?

Toidel Mahoney, the way you confuse pleasure with reproduction–well, I’d hate to see you try to eat a bar of chocolate.

And if evolution is a religion then scientists all need to stop paying taxes.

Eja: I know what you mean. Trolls are considered to be fictional beings.

In a desperate attempt to get some science benefit out of this thread :) is it valid to say that the male/female distinction is in a sense a within-species partition between an r-strategy (males produce very large numbers of gametes investing minimally in the development of each one) and a K-strategy (females produce relatively fewer, larger, egg cells, each of which gets much more resources than an individual sperm cell does)? Or is this not a helpful way of looking at it?

Creationists can go look up r/K strategy for themselves, while the adults are talking.

AL said:

It’s an impossible causality inversion.

“Impossible causality inversion.” Gotta love that! It’s the next big information theoretic conceptualization from the Dembski crew: ICI. Evolution cannot be an explanation where ICI is present, thus it is necessary to explain it with design.

Another opportunity to avoid taking Dembski’s bait and instead ask him where and when “ICI” was inserted in biological systems, and whether any required independent origin-of-life events. And force him to show more evasion.

Toidel, would you mind taking a break from your incredulity arguments to tell us your ideas regarding the whats and whens of design insertion? For starters, do you agree with Behe that life has a ~4 billion year history and that humans share common ancestors with other species?

Toidel Mahoney said:

Even if one believes that random chance created males & females, …

And no one does believe this.

Evolution is not random, it favors more highly adapted organisms.

Where do you get your misinformation?

Frank J said:

AL said:

It’s an impossible causality inversion.

“Impossible causality inversion.” Gotta love that! It’s the next big information theoretic conceptualization from the Dembski crew: ICI. Evolution cannot be an explanation where ICI is present, thus it is necessary to explain it with design.

Another opportunity to avoid taking Dembski’s bait and instead ask him where and when “ICI” was inserted in biological systems, and whether any required independent origin-of-life events. And force him to show more evasion.

Toidel, would you mind taking a break from your incredulity arguments to tell us your ideas regarding the whats and whens of design insertion? For starters, do you agree with Behe that life has a ~4 billion year history and that humans share common ancestors with other species?

Behe, as a member of the Den of Sodomites the Bible calls the whore of Babylon, is just as much of an evolutionist as Richard Dawkins or the clown in the white robes from whom he takes his marching order, perhaps in exchange for “quality time” with some altar boys. So, no, I don’t agree with Behe and his horde of evolutionists, the Holy Word of God is Toidel’s final authority!

arachnophilia said:

(Aren’t there species today that possess more than one mechanism of reproduction?)

yes! sea stars, for one.

Brine shrimp are capable of normal, sexual reproduction, and, if there are no males around, the female can produce clones of herself, via parthenogenesis.

Toidel Mahoney said:

So, no, I don’t agree with Behe and his horde of evolutionists, the Holy Word of God is Toidel’s final authority!

1 John 2:11 But the one who hates his brother is in the darkness and walks in the darkness, and does not know where he is going because the darkness has blinded his eyes.

1 John 3:15 Everyone who hates his brother is a murderer; and you know that no murderer has eternal life abiding in him.

1 John 4:20 If someone says, “I love God,” and hates his brother, he is a liar; for the one who does not love his brother whom he has seen, cannot love God whom he has not seen.

So, then, now that the Bible, too, demonstrates the blatantly obvious fact that you’re a liar who loves pretending that bigotry is supposed to be piety, why don’t you just shove off?

Toidel Mahoney Wrote:

So, no, I don’t agree with Behe and his horde of evolutionists, the Holy Word of God is Toidel’s final authority!

Behe is anything but an “evolutionist” but thanks for answering at least one question. Now, before anyone assumes that you’re another Ray Martinez (in a class by himself among anti-evolutionists) please tell us whether you agree with Ray’s old-earth-young biosphere chronology, and his assertion that even “microevolution” does not occur.

As you know, YECs, OECs, Flat-Earthers, Geocentrists, etc. interpret the “Holy Word of God” im mutually contradictory ways, so it can only help you to be as specific as possible about “what happened when.”

Raven,

Got a reference for that rotifer study? I would be very interested.

Stephen,

R and K selection have very specific meanings in ecology and refer to reproduction not production of gametes. Gamete production strategies are analogous but not identical to R and K selection. I prefer to think of it as a quanitiative and a qualitative strategies which are advantageous once anisomgamy has evolved.

Toidel,

Go somewhere else to display your homophobia. No one here cares.

Toidel Mahoney said:

the Holy Word of God is Toidel’s final authority!

Well, since you have a final authority, and it’s not Panda’s Thumb, there’s no point in your posting here, or anywhere else for that matter.

Toidel Mahoney said:

Even if one believes that random chance created males & females, doesn’t thinking about the teleological meaning of sexual organs (reproduction) undermine the religion of evolutionism? Evolutionism teaches that teleology doesn’t exist so that the mouth, anus or any hole in the wall is a proper sex organ. I wonder if PZ Myers or any other evolutionist could tell me a species that reproduced itself using the kind of sexuality found in prisons, San Francisco bathhouses, or other evolutionist meeting places.

The Intelligent Designer presumably didn’t teleologically intend for eyes to smell either, so why do I detect so much pungent bullshit from reading your comments?

Dan Wrote:

Well, since you have a final authority, and it’s not Panda’s Thumb, there’s no point in your posting here, or anywhere else for that matter.

While some post on these boards just to get attention, others just seem to lack the confidence in their claims, and seek validation, if only by being taken seriously enough to get replies to questions that have been answered 1000s of times before.

Note how, during the last few decades, they have been steadily retreating from making assertive statements about what the designer did and when.

softpedia.com:

Organisms Gave up Sexual Reproduction for DNA Theft Bdelloids able to incorporate foreign DNA By Gabriel Gache, Science News Editor

30th of May 2008, 13:30 GMT In animals the genetic material is inherited from the parents after conception. No other later action, except for rare parasitic infections that can modify your genetic material by inserting some of their DNA strands, can alter your DNA. But in bdelloid rotifers, a microscopic freshwater animal, such events happen all the time. Its DNA appears to contain a series of genes transferred from bacteria, fungi and even plants.

The discovery was made by Irina Arkhipova and Matthew Meselson from the MBL’s Josephine Bay Paul Center from Harvard University, assisted by graduate student at Harvard, Eugene Gladyshev.

“It is quite amazing that bdelloids are able to recruit foreign genes, which were acquired from remarkably diverse sources, to function in the new host. Bdelloids may have the capacity for tapping into the entire environmental gene pool, which may be of (evolutionarily) adaptive significance during expansion into new ecological niches, and may even contribute to bdelloid speciation”, says Arkhipova.

Over a period of 40 million years bdelloids evolved into more than 360 species by incorporating foreign DNA picked up from the environment and from other bdelloids. How on Earth they managed to do that is anybody’s guess. Usually, in animals the germ line is protected from the intrusions of foreign DNA by non heritable body cells, albeit bdelloids have no environmental exchange protection at all.

One reason would be the fact that bdelloids are able to survive total desiccation, which can kill most of the organisms on Earth. If water can no longer be found in the environment, then the bdelloids enter in an indefinite suspended dehydrated state, but come back to life as soon as water returns. During the desiccation stage the bdelloids suffer membrane and DNA damage in the rotifer. This enables foreign DNA to enter the germ line, becoming incorporated in the original DNA of the bdelloids once they are rehydrated.

The research team also showed that bdelloids are extremely good at recovering from the effects of ionizing radiation which breaks up the DNA code. The rotifer repairs the DNA after exposure to ionizing radiation, due to their unique ability to undergo desiccation. “The effects of radiation and desiccation may be quite similar and involve damage to chromosomal DNA as well as membranes”, Arkhipova says.

Foreign genes inside that of the bdelloid genomes appear to be clustered near the tips of the chromosomes and could have been picked up during desiccation. “It may be occasionally added to deprotected telomeres, as we previously demonstrated for mobile elements. Or it may simply not be selected against as efficiently as the more deleterious DNA insertions into the central, gene-rich regions of the chromosome”, Arkhipova says.

IANArotiferologist, but this subject might make a good PT post. The Bdelloids have always been a mystery.

The theory for Bdelloid rotifers is that they readily incorporate any DNA floating around in their environment.

This is because they can survive total dessication which fragments their genome. When they rehydrate, they have to stitch their genome back together and fast or die. So apparently any foreign DNA gets incorporated and some of this foreign DNA could be from other rotifers.

Doesn’t look like an efficient process. But with billions of rotifers and millions of years, seems to be enough. The Bdelloids have been evolutionarily diversifying without conventional sex.

FWIW, eukaryotic sex is expensive. Half the population doesn’t have children just runs around trying to (ahem) initiate reproductive contacts with the other half that does. The advantages seem to ouweigh a 50% hit in reproductive potential.

Thanks Raven.

I think Toidel Mahoney is going to turn out to be somethng like pòg mo thòn/póg mo thón (Gaelic for kiss my ass). And hence, a Poe.

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This page contains a single entry by Richard B. Hoppe published on August 30, 2009 12:32 AM.

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