Freethought & Rationalism Archive

lpetrich · 08-23-2003, 12:00 AM

Charles Darwin:
(on falsehood of evolution implying discrepant family trees...)
How do you know it could be anything, such as a wildly different tree?

What alternative do you think is plausible? Special creation of species with the appearance of evolution?

(unused areas of the genome...)
How do you know that an area isn't used?

Experience with molecular-level genetics: the more functionally-constrained something is, the more the sequences look alike between species. So some rapidly-evolving area implies low constraint.

But (i) dolphins and sharks; and (ii) marsupial and placental flying squirrels have some dramatic differences too.

So what? That's how one can recognize convergent evolution.

Furthermore, we really do not understand how the phenotype arises from the genotype.

Which is just plain wrong. We know how proteins are made from genes, and we are accumulating clues as to how other features are made.

Finally, you seem to be conveniently ignoring the many phylogenetic mismatches.

Like what?

If you believe that phylogentic congruence proves evolution, then what about the mismatches?

Whatever you have in mind. Please explain in more detail.

The Lone Ranger · 08-23-2003, 01:40 AM

Quote:

Originally posted by Charles Darwin:

The site is entitled "29+ Evidences for Macroevolution" but I came away thinking it is a real misnomer. Though it proposes to be an objective approach to the subject, it is actually a clever attempt to hoodwink those less knowledgable readers. It starts out by stating that "scientific theories are validated by empirical testing against physical observations." This affirming-the-consequent sleight of hand sets up the reader, as the page goes on to site all kinds of dubious "validations." I could give you 29+ validations for the flat-earth model, that doesn't mean it is true.

How, exactly, is this a �clever attempt to hoodwink those less knowledgable [sic] readers�? And where is the sleight of hand? One tests the validity of scientific hypotheses and theories by testing to see whether their predictions conform to reality, just as the site states. Do you know of some other way?

Every scientific theory makes predictions which can be, in principle, tested. If the theory fails these tests, then it must be modified or abandoned. While it�s true that if the predictions are verified, this doesn�t prove the theory to be true, it does give us more confidence in the theory. Evolutionary theory makes quite a number of predictions, and has a spectacularly good track record. So far, no one has found anything which contradicts it.

Quote:

I could give you 29+ validations for the flat-earth model, that doesn't mean it is true.

Can you? I don�t believe that you can.

Remember, for the flat-earth model to be a legitimate scientific theory, it must be based upon actual evidence, and it must make specific predictions which can be tested and falsified. If the predictions are shown to be false, they are not "validations" of the theory.

I would assume that a �validation� of the �theory� would be that the Earth appears to be flat to an observer. Upon casual observation, this may be so, but it takes only a little work to show that the prediction does not hold up. Anyone who has observed a ship sailing out to sea, for example, can clearly see that the Earth does not appear to be flat when viewed on a sufficiently large scale.

This is why the flat Earth theory is not taken seriously, because any non-trivial predictions it makes are easily falsified. So, please tell us which of the predictions of evolutionary theory have been falsified, and how. I know of no examples, myself.

Quote:

There is, in fact, no explanation for how life and her species are supposed to have evolved.

You asked for evidence that evolution is sufficiently well-established to be called a �fact.� That is precisely what the site offers. If it�s an explanation of evolutionary theory that you want, that information is readily available. You have only to ask.

Quote:

To head off that minor little problem, the page explains to the reader that "in evolutionary theory it is taken as axiomatic that an original self-replicating life form existed in the distant past, regardless of its origin." How convenient. Now all those thorny complexity problems can be swept under the rug as being outside of scope; but who are we fooling?

I�m at a loss to understand why so many people have the erroneous impression that evolutionary theory has anything whatsoever to do with the origins of life. Repeat after me: evolutionary theory is about how living things have evolved over time � since the origin(s) of life. Saying that evolutionary theory is incomplete or invalid because it doesn�t explain the origin of life is like saying that chemistry is an invalid field because it doesn�t explain the origins of atoms.

Quote:

And of course there still is no explanation for how something like our friend echolocation is supposed to have evolved; or did the first bacteria echolocate too?

The point of the site � as per your request � is to provide evidence for the fact of evolution, not to explain every little adaptation. Do you consult the owner�s manual of your automobile for an explanation of how the Bernoulli effect applies to the function of a carburetor? Do you throw the manual down in disgust and conclude that it's worthless because it doesn't provide that explanation?

Besides, as several posters have pointed out, echolocation isn�t difficult. Any animal with ears and the ability to produce sound can echolocate, at least crudely. Why is it so difficult to conceptualize how the process could have been refined by natural selection? Indeed, we have living examples of animals that can echolocate very crudely (humans, for example), to those that can echolocate rather more effectively (oilbirds, for instance), to those that can echolocate quite well (bats and cetaceans).

Quote:

The Introduction then ends up with this patronizing (mis) quote:
"Finally, there is this possibility: after I tell you something, you just can't believe it. You can't accept it. You don't like it. A little screen comes down and you don't listen anymore. I'm going to describe to you how Nature is - and if you don't like it, that's going to get in the way of your understanding it." �Feynman

Whether it�s a nice thought or not, Feynman has a legitimate point. If you�re determined not to believe a thing, you�re not going to be convinced by evidence, nor are you likely to gain a very thorough understanding of the subject. With respect, you give every indication of being someone who very much wants for evolution not to be true. If this is the case, it�s going to be difficult to convince you of the legitimacy of evolutionary theory on the basis of something as inconsequential as evidence.

Quote:

Well if evolution is a fact, then skeptics like me must just be nuts right? Place your opponents in the "irrational" category and everything will be alright. Why is it that evolutionists cannot seem to recognize that their theory is, in fact, not a scientific fact?

Well, to put it bluntly, there are many thousands of evolutionary biologists over the world who have studied the matter quite thoroughly. They�re quite convinced that the evidence in favor of evolution is so voluminous � and the evidence against it is conspicuously nonexistent � that they�re quite comfortable calling it an established fact. Oddly, the only ones who deny that evolution is a fact consistently show themselves to be a.) ignorant of the subject, and/or b.) strongly prejudiced against acceptance of evolution for religious/political/whatever reasons.

I note, in passing, that you still seem to be incapable of distinguishing between the fact of evolution (that all organisms show clear and unmistakable evidence of being related through common descent) and the theory of evolution (which explains that fact). Why is that so difficult a concept? If one didn�t know better, one would suspect that you conflate the ideas because you don�t want to understand the differences.

In a later post, you ask:

Quote:

Do you know how big the design space is which evolution had to randomly search through and hit upon, and test, this design? How many years were available, and what mutational rates would be required? I don't think we have a good handle on this, so this is really just speculation.

If you think that natural selection is a random process, then yours is a very poor understanding of evolutionary theory indeed. By the way, no one is suggesting that evolution produces "ideal" or "perfect" adaptations � indeed, examples of just how inefficient a process it can be abound.

Quote:

"Probably the most well known case of atavism is found in the whales. According to the standard phylogenetic tree, whales are known to be the descendants of terrestrial mammals that had hindlimbs. Thus, we expect the possibility that rare mutant whales might occasionally develop atavistic hindlimbs."

Aside from the fact that nothing is "known" from phylogenetic trees, the idea that hindlimbs are a prediction of evolution is a joke. You don't really believe that evolution would be rejected if such mutants were never discovered do you? What if tails were never discovered in humans? This has got to be one of the most absurd claims I've ever heard. Of course, the text falls back on the standard cretionist punching bag opponent as if to present a serious rebuttal.

Perhaps you should re-read that paragraph. Certainly, within the context of phylogenetic trees, it is known that whales are descended from terrestrial mammals with hindlimbs. That�s what the trees predict, and that�s precisely what the author is saying � that it�s a known fact that the phylogenetic trees predict this.

So, one way to test the validity of the phylogenetic trees � and of the evolutionary theory that they�re based upon � is to see if the predictions they make hold up in the real world. The trees predict that whales are descended from ancestors with hindlimbs. A corollary of that prediction is that whales should still possess genes for hindlimbs, and therefore we would expect to occasionally find a whale with hindlimbs. This is a straightforward prediction, and not in the least absurd. We can guage the validity of the theory by looking to see if whales are occasionally born with hindlimbs. If we didn�t see the occasional whale born with hindlimbs, this would indeed be evidence that evolutionary theory was in need of revision. Furthermore, if whales were never observed to have atavistic hindlimbs, and a careful analysis of whales� DNA showed conclusively that they did not have genes that were homologous to those which cause the growth of hindlimbs in terrestrial mammals, that would indeed be a serious blow to evolutionary theory.

That�s the point. The observations could have provided evidence that evolution is not a fact. If so, we�d have no choice but to accept that. They didn�t though; they did just the opposite.

That�s how science is done. We put our hypotheses and theories on the chopping block by testing their claims against reality. If they fail the tests, out they go. So far, evolutionary theory has not failed any of the tests we�ve been able to devise for it.

******

Let�s simplify things a bit.
[list=1][*]According to all the available evidence � from geology, astronomy, cosmology, etc. � the Earth is very old, over four billion years old, in fact.[*]Molecular biology and genetics provide overwhelming evidence that all living organisms are related and share common ancestry. [*]The fossil record provides unambiguous evidence that organisms have been evolving for quite some time.[*]Populations of organisms are observed to evolve in the wild. [*]Studies of natural populations show not only that they evolve, but that they often evolve at rates that are orders of magnitude faster than is necessary to explain the observed rates of change in the fossil record.*[/list=1]
A question arises. Since all the evidence we have indicates that the Earth is billions of years old, and since molecular and genetic data clearly indicate that all extant organisms are related through common descent, and since field studies consistently show that populations can and do evolve at rates which are more than adequate to explain the rates of change implied by the fossil record, what evidence do you have that evolution is not true and that 99.99% of the world�s biologists, geologists, paleontologists, astronomers, cosmologists, etc. are completely deluded?

* See this study, for example.

Perhaps you think that there exists some sort of �genetic� barrier which would somehow prevent one species from evolving into another, I would like to point out that no studies have ever provided evidence that such barriers exist. Consider ring species, for example.

A ring species occurs when a single species becomes distributed in a circular pattern over a large geographical area. Neighboring populations of the species vary slightly and can interbreed, but those populations at the extremes of the distribution � the opposite ends that link to form the circle � are sufficiently different that they do not interbreed and function as separate species. In fact, they would be considered to be separate species except that the intermediates which link them form a continuum. Ring species are a particularly nice example of evolution in action, because we can see all of the intermediates that link two related �species.�

Perhaps the best-known example of a ring species is the salamander Ensatina eschscholtzi. Here's a picture showing the species' distribution and variation.

The subspecies at the endpoints of the ring (Ensatina eschscholtzi eschscholtzi and Ensatina eschscholtzi klauberi) come into contact with each other, and thus close the ring. Yet they're so different in appearance that the would certainly be classified as separate species were it not for the existence of all the intermediates which connect them.

Here's E. e. eschscholtzi:

Here's E. e. klauberi:

In most areas where they co-occur, E. e. eschscholtzi and E. e. klauberi seldom if ever interbreed, as has been confirmed by both behavioral and genetic studies. See this article, for example. Indeed, the genetic differences between E. e. eschscholtzi and E. e. klauberi are equal to or greater than the genetic differences between different species.

The point is that this looks exactly like an example of speciation in action. It certainly qualifies as very strong evidence of evolution in action. Moreover, it clearly demonstrates that there is no magical genetic barrier which would prevent one species from evolving into another.

***

Let's simplify even more.

You asked for evidence that evolution is a fact. That evidence is readily available. The genetic unity of life, the fact that species can be organized into a nested hierarchy of apparent relatedness, the fact that independent methods produce similar or identical phylogenies, the existence of intermediate forms, the presence of atavistic structures, the presence of vestigial structures, ontological features, biogeography, and so forth -- all of these provide overwhelming evidence that evolution is a fact.

You can, of course, invent all sorts of ad hoc "explanations" for these lines of evidence. Perhaps a Creator -- for some strange reason -- wished to create life in such a way as to make it look like it evolved over time, but that's not a testable or falsifiable hypothesis, and so is of no use.

The overwhelming verdict of the scientific community is that the evidence in favor of evolution is so complete that it's pointless to call it anything other than a fact. Your choices are simple: 1.) accept this and move on, or 2. show us why we're wrong.

Hint: Whining that no one has explained every little detail is not the same thing as providing evidence that the conclusion is false. If you see and videotape Person "A" shooting Person "B", if you see Person "B" bleeding afterward, if you see the surgeons removing the bullet from Person "B"'s body, if you hear Person "A" confess to the crime -- do you claim that it's not a fact that Person "A" shot Person "B" because you don't know where the bullet was manufactured?

Cheers,

Michael

RufusAtticus · 08-23-2003, 02:00 AM

Quote:

Originally posted by Charles Darwin
I could give you 29+ validations for the flat-earth model, that doesn't mean it is true.

Okay. I'll bite. Give me 29+ evidences of the flat-earth, complete with references for each one from the primary scientific literature.

Quote:

There is, in fact, no explanation for how life and her species are supposed to have evolved.

Completely false. Life evolves via mutation, selection, drift, migration, and the mating system.

Quote:

To head off that minor little problem, the page explains to the reader that "in evolutionary theory it is taken as axiomatic that an original self-replicating life form existed in the distant past, regardless of its origin." How convenient. Now all those thorny complexity problems can be swept under the rug as being outside of scope; but who are we fooling?

They're not trying to fool anyone, just telling it how it is. Evolution does not concern itself with the origin of life. That is because, for evolution to occur, it requires an imperfect replicator. Therefore, anything that leads up to that first imperfect replicator is logically not evolution.

Quote:

Aside from the fact that nothing is "known" from phylogenetic trees, the idea that hindlimbs are a prediction of evolution is a joke.

Read the section again. Not to use of the term "possibility."

Quote:

Ahh, but who are we fooling? Allele frequencies change all the time. So what? You're not creating anything new.

It's creating new allele frequencies. Most people realize that when talking about changing allele frequencies 0.0->0.001 is a change in allele frequency. Clearly mutation falls under that description, and clearly new, novel genes are formed all the time.

Quote:

I hate to have to be the one to tell you this, but there's a whole bunch we don't know about micro biology. So, no, I'm afraid I can't explain the presence of the telomeres in the middle of chromosome 2 in humans and apes.

Anyone with a good high-school biology background should be able to know how it occured. It is hardly a mystery. Teleomeres are found in the middle of human chromosome 2 because it is the result of an ancient fussion between two chromosomes. In the other apes, these chromosomes are still separate.

Quote:

You think evolution created these chromosomes, even though you don't know how it could have done said task. Nor do you have the slightest idea of what function said design might serve.

CD, perhaps you shouldn't go around telling people what they can or can't do without first testing them on it. Such rhetoric is no different than lying about someone else, which is not a good way to opperate in an intellectual discussion.

Chromosomes are simply a DNA polymere, packaged with proteins. No mystery there.
Chromosomes function to keep the hereditary information togering in a well controled location(s) so that when cell division occurs there is low chance that one of the daughter cells is missing something. Chromosomes are also important in regulating gene expression.

caravelair · 08-23-2003, 08:57 AM

Quote:

Originally posted by Charles Darwin
I see. You and the other folks -- I see a pattern. Of course we cannot believe they were created, so ..., evolution must be true. We were talking about a scientific fact, but this is a switch. What you are really saying is this is a metaphysical fact. Given your metaphysical position, evolution is a fact. Ok, I'll buy that.

i believe you have completely avoided the question that was asked by changing the subject entirely. i would like to know your answer to the question, so i'll post it again:

Quote:

Originally posted by lpetrich
And if you do, do you believe that it represents ancestor-descendant chains or something like

55 myr: *POOF!* Hyracotherium was created
50 myr: *POOF!* Orohippus was created
40 myr: *POOF!* Mesohippus was created
35 myr: *POOF!* Miohippus was created
17 myr: *POOF!* Merychippus was created
12 myr: *POOF!* Dinohippus was created
4 myr: *POOF!* Equus was created
2 myr: *POOF!* Various present-day equine species created

And in human ancestry:

5 myr: *POOF!* Ardipithecus ramidus was created
4 myr: *POOF!* Australopithecus afarensis was created
3 myr: *POOF!* Australopithecus africanus was created
2.7 myr: *POOF!* Paranthropus aethiopicus was created
2.3 myr: *POOF!* Paranthropus boisei was created
2 myr: *POOF!* Paranthropus robustus was created
2.5 myr: *POOF!* Homo habilis was created
2 myr: *POOF!* Homo erectus was created
0.7 myr: *POOF!* Homo heidelbergensis was created
0.3 myr: *POOF!* Homo neanderthalensis was created
0.1 myr: *POOF!* Homo sapiens was created

With each species having a suspicious resemblance to existing species.

so... do you believe that each of theseb species was created, died out, and then replaced with the creation of another very similar species?

Jet Black · 08-23-2003, 09:22 AM

Quote:

Originally posted by Charles Darwin
Yes, I do understand the retroviral insertion argument. They are supposed to be irreversible markers; which is why, for example, the [Ape + chimp but not human] ERV is interesting since at the homologous human site the DNA sequence clearly shows a clean pre insertion site. I also understand know that ERVs can have site selectivity. And I also understand that, if evolution is true, there must have been a sort of "punctuated equilibrium" in the HERV world; and that HERVs must have played a role in evolution since they, in fact, have a regulatory function.

the ape and chimp ERV is easily explainable by saying that it was introduced into the ape-chimp line after the human line split off.

what is the regulatory finction of the HERV?

lpetrich · 08-23-2003, 09:33 AM

Charles Darwin:
(endosymbiosis:)
You mean the story that a big cell ate up a little cell and forever after the little one was there, working away to produce all those ATPs via that convenient electron transport chain that just happened to be there, with its series of re-dox steps that just happened to be there, and the ATPase which just happened to be there? Well, you're right, I don't buy it.

Except that various bacteria also have electron-transport chains and membrane-based ATP synthesis. And it is not difficult to imagine a process of natural selection that results in the selection of an aerobic organic-eating bacterium as the endosymbiont rather than a bacterium with a different metabolism. Imagine a protoeukaryote eating lots of different kinds of bacteria and some of them staying inside, with the most useful of them helping their hosts reproduce more than the others.

Aside from all this complexity, there is thorny little problem of organelles common to prokaryotes and eukaryotes. Doesn't quite fit the theory of endosymbiosis.

So what? Genome-less organelles like ribosomes and flagella are directly produced by their host cells.

Oh, also, why is the possession of genetic material mysterious for an organelle?

What's the point of an organelle having its own genome, especially a very reduced genome? Especially when cells can create several kinds of genome-less organelles from their cytoplasm.

[Just fixing an inadvertant smiley. -GunnerJ]

lpetrich · 08-23-2003, 09:44 AM

Charles Darwin:
... Perhaps by some magical process species transform themselves into other species. ...

As opposed to some magical process that poofs species into existence?

How new species form is a subject of active research; and so far, there is no need to consider it a magical process.

That's one reason why the genome of the fruit fly Drosophila pseudoobscura is being sequenced; it is close to lab fly Drosophila melanogaster, and comparison of the two flies' genomes should help indicate what distinguishes a species from some very similar species. This is also why there are some proposals to sequence two other close species: D. simulans and D. yakuba.

lpetrich · 08-23-2003, 09:55 AM

Charles Darwin:
(evolution of echolocation...)
I don't say one big jump, nor do I say it cannot have evolved. I say it isn't likely.

But when you mention the details of the fancier forms of echolocation, you seem like you believe in the one-big-jump theory. So what do you think happened?

Also, the analogy with human technology suffers from the fact that human designers were involved.

Except that human designers do not create fully-developed technologies in one swell foop -- and are not capable of doing so. Even the greatest geniuses work in collaboration with others. As a result, development of technology proceeds incrementally, in a fashion that resembles biological evolution.

(Reciprocal altruism...)
Do you know how big the design space is which evolution had to randomly search through and hit upon, and test, this design? How many years were available, and what mutational rates would be required? I don't think we have a good handle on this, so this is really just speculation.

That would require understanding how genes translate into behavior, which has been much more difficult than understanding how genes translate into proteins.

But one can get around that by studying vampire bats' behavioral repertoire to work how blood-sharing could have evolved.

lpetrich · 08-23-2003, 10:12 AM

Charles Darwin:
(what topology of horse relationships...)
I really don't know, but I do know that the mythical horse sequence convinced many a lay person for the better part of a century before it was finally admitted to be, well, ... mythical.

My guess is that CD's main "knowledge" of horse evolution comes from creationist quote miners. The only thing that's been discredited is a simple straight-line model of horse evolution -- it is a very bushy sort of tree, with only some recent branchings surviving.

What we have is a bunch of different species which, if evolution is true, must have punctuated into each other.

So what? And I take it that you endorse the *POOF!* theory of origins.

I also know that evolution, beyond handwaving, doesn't explain how any of those species got there in the first place anyway. Why is it you think this makes evolution a scientific fact?

What would you consider acceptable evidence, O CD? Going back in time in a time machine and watching all of those ancestral species?

I see. You and the other folks -- I see a pattern. Of course we cannot believe they were created, so ..., evolution must be true. ...

No, you extrapolate.

All you have to do to start echolocating is making sounds and listening for echoes. It's that simple.

Sorry, it is a little more complicated than that.

How is even the simplest form of echolocation more complicated that that?

Charles Darwin · 08-23-2003, 11:00 AM

Quote:

Originally posted by lpetrich
Charles Darwin:
(on falsehood of evolution implying discrepant family trees...)
How do you know it could be anything, such as a wildly different tree?

What alternative do you think is plausible? Special creation of species with the appearance of evolution?

(unused areas of the genome...)
How do you know that an area isn't used?

Experience with molecular-level genetics: the more functionally-constrained something is, the more the sequences look alike between species. So some rapidly-evolving area implies low constraint.

But (i) dolphins and sharks; and (ii) marsupial and placental flying squirrels have some dramatic differences too.

So what? That's how one can recognize convergent evolution.

Furthermore, we really do not understand how the phenotype arises from the genotype.

Which is just plain wrong. We know how proteins are made from genes, and we are accumulating clues as to how other features are made.

Finally, you seem to be conveniently ignoring the many phylogenetic mismatches.

Like what?

If you believe that phylogentic congruence proves evolution, then what about the mismatches?

Whatever you have in mind. Please explain in more detail.

When you say life looks like it evolved you're begging the question. That is the question at hand. I would argue that life, the most complex thing known, does not look like it evolved; not by a long shot.

You also beg the question when you say that rapidly evolving areas have no function (ie, low constraint). You cannot claim unused segments as evidence for evolution, and then support your claim by saying you know they are unused because they are rapidly evolving. You are presupposing evolution in order to present evidence for evolution.

And no, I'm not just "plain wrong" that we still lack many details of how the phenotype is created from the genotype. Knowing how protein synthesis works is only one step in the process.

Regarding phylogenetic mismatches, I'm amazed that I'm even being asked for examples. Look in any research journal or review article dealing with phylogeny. Examples are abundant.

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08-23-2003, 12:00 AM	#91
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	Charles Darwin: (on falsehood of evolution implying discrepant family trees...) How do you know it could be anything, such as a wildly different tree? What alternative do you think is plausible? Special creation of species with the appearance of evolution? (unused areas of the genome...) How do you know that an area isn't used? Experience with molecular-level genetics: the more functionally-constrained something is, the more the sequences look alike between species. So some rapidly-evolving area implies low constraint. But (i) dolphins and sharks; and (ii) marsupial and placental flying squirrels have some dramatic differences too. So what? That's how one can recognize convergent evolution. Furthermore, we really do not understand how the phenotype arises from the genotype. Which is just plain wrong. We know how proteins are made from genes, and we are accumulating clues as to how other features are made. Finally, you seem to be conveniently ignoring the many phylogenetic mismatches. Like what? If you believe that phylogentic congruence proves evolution, then what about the mismatches? Whatever you have in mind. Please explain in more detail.

08-23-2003, 09:33 AM	#96
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	Charles Darwin: (endosymbiosis:) You mean the story that a big cell ate up a little cell and forever after the little one was there, working away to produce all those ATPs via that convenient electron transport chain that just happened to be there, with its series of re-dox steps that just happened to be there, and the ATPase which just happened to be there? Well, you're right, I don't buy it. Except that various bacteria also have electron-transport chains and membrane-based ATP synthesis. And it is not difficult to imagine a process of natural selection that results in the selection of an aerobic organic-eating bacterium as the endosymbiont rather than a bacterium with a different metabolism. Imagine a protoeukaryote eating lots of different kinds of bacteria and some of them staying inside, with the most useful of them helping their hosts reproduce more than the others. Aside from all this complexity, there is thorny little problem of organelles common to prokaryotes and eukaryotes. Doesn't quite fit the theory of endosymbiosis. So what? Genome-less organelles like ribosomes and flagella are directly produced by their host cells. Oh, also, why is the possession of genetic material mysterious for an organelle? What's the point of an organelle having its own genome, especially a very reduced genome? Especially when cells can create several kinds of genome-less organelles from their cytoplasm. [Just fixing an inadvertant smiley. -GunnerJ]

08-23-2003, 09:44 AM	#97
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	Charles Darwin: ... Perhaps by some magical process species transform themselves into other species. ... As opposed to some magical process that poofs species into existence? How new species form is a subject of active research; and so far, there is no need to consider it a magical process. That's one reason why the genome of the fruit fly Drosophila pseudoobscura is being sequenced; it is close to lab fly Drosophila melanogaster, and comparison of the two flies' genomes should help indicate what distinguishes a species from some very similar species. This is also why there are some proposals to sequence two other close species: D. simulans and D. yakuba.

08-23-2003, 09:55 AM	#98
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	Charles Darwin: (evolution of echolocation...) I don't say one big jump, nor do I say it cannot have evolved. I say it isn't likely. But when you mention the details of the fancier forms of echolocation, you seem like you believe in the one-big-jump theory. So what do you think happened? Also, the analogy with human technology suffers from the fact that human designers were involved. Except that human designers do not create fully-developed technologies in one swell foop -- and are not capable of doing so. Even the greatest geniuses work in collaboration with others. As a result, development of technology proceeds incrementally, in a fashion that resembles biological evolution. (Reciprocal altruism...) Do you know how big the design space is which evolution had to randomly search through and hit upon, and test, this design? How many years were available, and what mutational rates would be required? I don't think we have a good handle on this, so this is really just speculation. That would require understanding how genes translate into behavior, which has been much more difficult than understanding how genes translate into proteins. But one can get around that by studying vampire bats' behavioral repertoire to work how blood-sharing could have evolved.

08-23-2003, 10:12 AM	#99
lpetrich Contributor Join Date: Jul 2000 Location: Lebanon, OR, USA Posts: 16,829	Charles Darwin: (what topology of horse relationships...) I really don't know, but I do know that the mythical horse sequence convinced many a lay person for the better part of a century before it was finally admitted to be, well, ... mythical. My guess is that CD's main "knowledge" of horse evolution comes from creationist quote miners. The only thing that's been discredited is a simple straight-line model of horse evolution -- it is a very bushy sort of tree, with only some recent branchings surviving. What we have is a bunch of different species which, if evolution is true, must have punctuated into each other. So what? And I take it that you endorse the POOF! theory of origins. I also know that evolution, beyond handwaving, doesn't explain how any of those species got there in the first place anyway. Why is it you think this makes evolution a scientific fact? What would you consider acceptable evidence, O CD? Going back in time in a time machine and watching all of those ancestral species? I see. You and the other folks -- I see a pattern. Of course we cannot believe they were created, so ..., evolution must be true. ... No, you extrapolate. All you have to do to start echolocating is making sounds and listening for echoes. It's that simple. Sorry, it is a little more complicated than that. How is even the simplest form of echolocation more complicated that that?

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