Has evolution done stopped?

[lucaspa]

No, I'm not misunderstanding him. I just read the Origin of a Species. Theory of Natural Selection.



And I'm saying that evolution or no evolution, speciation or no speciation, a bird has always been, and will always be, a bird.

You know, it's too bad you didn't read the WHOLE chapter on natural selection. If you had, you wouldn't have said that natural selection is the catalyst, because Darwin makes it clear in that chapter that it is the environment that is the driving "force". Natural selection is the process that gives designs.

In the first Edition, the entire quote is:

Natural selection acts solely through the preservation of variations in some way advantageous, which consequently endure. But as from the high geometrical powers of increase of all organic beings, each area is already fully stocked with inhabitants, it follows that as each selected and favoured form increases in number, so will the less favoured forms decrease and become rare. Rarity, as geology tells us, is the precursor to extinction. We can, also, see that any form represented by few individuals will, during fluctuations in the seasons or in the number of its enemies, run a good chance of utter extinction. But we may go further than this; for as new forms are continually and slowly being produced, unless we believe that the number of specific forms goes on perpetually and almost indefinitely increasing, numbers inevitably must become extinct. That the number of specific forms has not indefinitely increased, geology shows us plainly; and indeed we can see reason why they should not have thus increased, for the number of places in the polity of nature is not indefinitely great,—not that we
have any means of knowing that any one region has as yet got its maximum of species.

Now, the key here is the phrase "each area" Darwin is talking about change WITHIN an area and within an ecological niche in that area. IOW, Darwin is talking about phyletic gradualism. In this, the ENTIRE population transforms, so that when Darwin is talking about "forms" he is talking about the different variations within the population.

But this is very different than saying that the parent species must inevitably go extinct as the new species is forming.

Darwin talked most about phyletic gradualism. However, most speciation isn't by this route. Instead most speciation has been by allopatric and sympatric speciation. In those cases, the new species are separated by ecological niche or geography from the original species and never even compete with it.

Now, within a given area, different species often compete for the same resources, and one can drive another to extinction. However, this happens most often when a new species migrates into an area and is a foreign species. Such as the coati driving raccoons to extinction in N. America. The coati comes from S. America and occupies the same ecological niche. But does it better. So as the coati moves north, the raccoon becomes extinct in those areas the coati invades.

But coatis are not descendents of raccoons.

 

[Valen]

You know, it's too bad you didn't read the WHOLE chapter on natural selection. If you had, you wouldn't have said that natural selection is the catalyst, because Darwin makes it clear in that chapter that it is the environment that is the driving "force". Natural selection is the process that gives designs.

In the first Edition, the entire quote is:


Now, the key here is the phrase "each area" Darwin is talking about change WITHIN an area and within an ecological niche in that area. IOW, Darwin is talking about phyletic gradualism. In this, the ENTIRE population transforms, so that when Darwin is talking about "forms" he is talking about the different variations within the population.

But this is very different than saying that the parent species must inevitably go extinct as the new species is forming.

Darwin talked most about phyletic gradualism. However, most speciation isn't by this route. Instead most speciation has been by allopatric and sympatric speciation. In those cases, the new species are separated by ecological niche or geography from the original species and never even compete with it.

Now, within a given area, different species often compete for the same resources, and one can drive another to extinction. However, this happens most often when a new species migrates into an area and is a foreign species. Such as the coati driving raccoons to extinction in N. America. The coati comes from S. America and occupies the same ecological niche. But does it better. So as the coati moves north, the raccoon becomes extinct in those areas the coati invades.

But coatis are not descendents of raccoons.

Let's attack this Darwinian theory. I found a blind spot!

 

[Jet Black]

Let's attack this Darwinian theory. I found a blind spot!

go on, which bit don't you like?

 

[Valen]

Come all put all the Darwinian principles down we wanted to see it!

 

[lucaspa]

What Darwin is saying is that there is a catalyst that causes old species to speciate. He calls this process Natural Selection.

The catalyst is not natural selection. From the beginning of Chapter 4 of Origin of the Species:

We shall best understand the probable course of natural selection by taking the case of a country undergoing some physical change, for instance, of climate. The proportional numbers of its inhabitants would almost immediately undergo a change, and some species might become extinct.

Notice that it is the CLIMATE that is the catalyst that causes old species to change. Now, in this chapter Darwin is not talking about speciation as we are: cladogenosis or the formation of a new species while the old exists. Instead, he is talking about phyletic gradualism or the transformation of the whole population to a new species.

Yes, it is the process of natural selection that provides the new adaptations.

As a result of this process, the old species must die off.

That isn't what Darwin said. What he said was

From these several considerations I think it inevitably follows, that as new species in the course of time are formed through natural selection, others will become rarer and rarer, and finally extinct.

Not THE old species, as in the ancestor, but "OTHERS" as in other species but NOT necessarily the ancestors. This is very different from what you claim. Darwin does document cases where new species migrate in and displace ones already there and drive them to extinction. But those driven to extinction weren't the ancestors.

There are only two reasons for an organism to speciate

1) Not fit for it's environment
2) Divine or human intervention.

1) can happen if the climate changes and you have phyletic gradualism. However, this is not cladogenesis -- making another species -- but rather tansforming an existing species. Thus, it's not "speciation" as we are using the term here.

2) has happened as humans dictate the environment.

However, these are not the ONLY reasons for a population to speciate. Notice I said POPULATION and not organism. Organisms don't speciate, populations of organisms do.

Other reasons are"
3) isolation in a new geological area.
4) empty ecological niches. This is the cause of the radiations observed in Darwin finches and mammals after the KT extinction. It is also operative in sympatric speciation.

Now, speaking of what Darwin says, did you read further in Chapter 4 on "divergence of characters"? Specifically I'm thinking of the diagram

http://pages.britishlibrary.net/charles.darwin2/diagram.jpg

and this quote:

I see no reason to limit the process of modification, as now explained, to the formation of genera alone. ... We shall also have two very distinct genera descended from (I) and as these latter two genera, both from continued divergence of character and from inheritance from a different parent, will differ widely from the three genera descended from (A), the two little groups of genera will form two distinct families, or even orders, according to the amount of divergent modification supposed to be represented in the diagram. And the two new families, or orders, will have descended from two species of the original genus; and these two species are supposed to have descended from one species of a still more ancient and unknown genus.

In other words, birds will not always be "birds" because the process of modification will inevitably make the descendent species a new family, order, or class.

So, Drfeelgood, please show us the brick walls in Darwin's diagram that would stop the process of modification.

 

[lucaspa]

Let's attack this Darwinian theory. I found a blind spot!

Phyletic gradualism has already been attacked extensively in the scientific literature.

Eldredge and Gould led the charge with Punctuated Equilibrium, noting that the fossil record supported cladogenesis with allopatric speciation and not phyletic gradualism as the MAJOR mode of speciation.

Examples of phyletic gradualism are known, but they are rare.

 

[lucaspa]

Come all put all the Darwinian principles down we wanted to see it!

Read Orgin of the Species. The book is much too long to put it all here.

Or you could read Ernst Mayr's What Evolution Is to get a good overview of evolution. Futuyma's Evolutionar Biology will give you the details.

Is there something in particular you want to discuss?

 

[euphoric]

That's true, when viewed of it's own accord (which is my bad for only quoting the one paragraph). If I had quoted the preceding group of paragraphs as well, where he outlined the basis for his conclusion in detail, it would make a lot more sense.

Baloney. In fact you only quoted a single sentence. Here is the section on extinction in its entirety:

This subject will be more fully discussed in our chapter on Geology; but it must be here alluded to from being intimately connected with natural selection. Natural selection acts solely through the preservation of variations in some way advantageous, which consequently endure. But as from the high geometrical powers of increase of all organic beings, each area is already fully stocked with inhabitants, it follows that as each selected and favoured form increases in number, so will the less favoured forms decrease and become rare. Rarity, as geology tells us, is the precursor to extinction. We can, also, see that any form represented by few individuals will, during fluctuations in the seasons or in the number of its enemies, run a good chance of utter extinction. But we may go further than this; for as new forms are continually and slowly being produced, unless we believe that the number of specific forms goes on perpetually and almost indefinitely increasing, numbers inevitably must become extinct. That the number of specific forms has not indefinitely increased, geology shows us plainly; and indeed we can see reason why they should not have thus increased, for the number of places in the polity of nature is not indefinitely great, not that we have any means of knowing that any one region has as yet got its maximum of species. probably no region is as yet fully stocked, for at the Cape of Good Hope, where more species of plants are crowded together than in any other quarter of the world, some foreign plants have become naturalised, without causing, as far as we know, the extinction of any natives.

Furthermore, the species which are most numerous in individuals will have the best chance of producing within any given period favourable variations. We have evidence of this, in the facts given in the second chapter, showing that it is the common species which afford the greatest number of recorded varieties, or incipient species. Hence, rare species will be less quickly modified or improved within any given period, and they will consequently be beaten in the race for life by the modified descendants of the commoner species.

From these several considerations I think it inevitably follows, that as new species in the course of time are formed through natural selection, others will become rarer and rarer, and finally extinct. The forms which stand in closest competition with those undergoing modification and improvement, will naturally suffer most. And we have seen in the chapter on the Struggle for Existence that it is the most closely-allied forms, varieties of the same species, and species of the same genus or of related genera, which, from having nearly the same structure, constitution, and habits, generally come into the severest competition with each other. Consequently, each new variety or species, during the progress of its formation, will generally press hardest on its nearest kindred, and tend to exterminate them. We see the same process of extermination amongst our domesticated productions, through the selection of improved forms by man. Many curious instances could be given showing how quickly new breeds of cattle, sheep, and other animals, and varieties of flowers, take the place of older and inferior kinds. In Yorkshire, it is historically known that the ancient black cattle were displaced by the long-horns, and that these 'were swept away by the short-horns' (I quote the words of an agricultural writer) 'as if by some murderous pestilence.'

No where in this does Darwin suggest that, because part of a population evolves, the original poulation must become extinct. Again, he is simply pointing out that because the number of species is not growing steadily toward infinity due to competition for resources, and new species are evolving, some species do suffer extinction.

You completely misrepresented Darwin's position on this, but let's assume for the sake of argument that your characterization was correct. What conceivable damage would such a thing do to the validity of evolutionary theory?

-brett

 

[bagfullofsnakes]

And that is what happens with evolution. We ACCEPT the validity of evolution because of the material evidence.

I always use the term "accept" for evolution rather than "believe" to avoid the confusion you have by using definitions 1 and 3.

"I accept evolution", is always my standard reply. It's very difficult to communicate the difference between "accept vs. believe" to people. Analogies can be helpful.

Also, in regards to this thread, I usually retort to the question of "Do you believe in evolution?", with a reply somewhat like this:

BFOS
Well...I accept evolution as a valid theory. It is one of the most, if not the most, successful theories in ANY field of science. It explains all known facts/phenomena in biology.

Now, let me ask you a question: What on earth, except for an act of god, could prevent evolution?

THEM
Huh?

BFOS
Right, what could possibly prevent it from happening? Consider this: Do organisms change? That is, when organisms reproduce, do they make perfect copies of themselves?

THEM
Well...no...

BFOS
OK. Now, what about environments? Do environments change, or do they stay the same?

THEM
Um, I'd have to say that environments change.

BFOS
OK then...If (1) organisms do NOT make perfect copies of themselves when they reproduce, and (2) environments do NOT remain consistent, and unchanging, then what...other than an act of god...could prevent evolution from occuring?

 

[Nathan David]

BagfullofSnakes, that's a great way of looking at it.

 

[SirKenin]

I never said natural selection was the catalyst. I think you guys may have misunderstood me. I said that a catalyst causes speciation. I said that there is only two types of catalysts. The old species then dies off (of course if God or man had their hands in the process (ie they are the catalyst) of speciation, the old species doesn't have to necessarily die off. Then it would no longer be natural selection, either)

This "natural" process of speciation/evolving invoked by catalyst is called Natural Selection according to the Darwinian Theory of Evolution.

And around and around we go.

 

[lucaspa]

I never said natural selection was the catalyst. I think you guys may have misunderstood me. I said that a catalyst causes speciation. I said that there is only two types of catalysts. The old species then dies off (of course if God or man had their hands in the process (ie they are the catalyst) of speciation, the old species doesn't have to necessarily die off. Then it would no longer be natural selection, either)

Well, there are more than two causes for speciation. And we have shown that the statement "the old species dies off" is not true. Species do go extinct, but that is not linked to speciation.

This "natural" process of speciation/evolving invoked by catalyst is called Natural Selection according to the Darwinian Theory of Evolution.

I'm afraid not. Natural selection is the process that yields adaptations. Here is how Darwin summarized it at the end of Chapter 4. Again, drfeelgood, it doesn't appear as though you have even read all the chapter, much less anything else about evolution that hasn't come from creationist sources.

"If, during the long course of ages and under varying conditions of life, organic beings vary at all in the several parts of their organization, and I think this cannot be disputed; if there be, owing to the high geometric powers of increase of each species, at some age, season, or year, a severe struggle for life, and this certainly cannot be disputed; then, considering the infinite complexity of the relations of all organic beings to each other and to their conditions of existence, causing an infinite diversity in structure, constitution, and habits, to be advantageous to them, I think it would be a most extraordinary fact if no variation ever had occurred useful to each beings welfare, in the same way as so many variations have occured useful to man. But if variations useful to any organic being do occur, assuredly individuals thus characterized will have the best chance of being preserved in the struggle for life; and from the strong principle of inheritance they will will tend to produce offspring similarly characterized. This principle of preservation, I have called, for the sake of brevity, Natural Selection." [Origin, p 127 6th ed.]

Natural selection is the process responsible for the designs in biological organisms.

Speciation for sexually reproducing organisms also involves reproductive isolation. Now, it does turn out that natural selection does play a part in reproductive isolation by selecting for characteristics that contribute to reproductive isolation in many known cases. However, sexual selection is also responsible in many cases for causing reproductive isolation.

Why don't you read the rest of Origin and then Ernst Mayr's What Evolution Is before you try telling us what evolution is?

 

[lucaspa]

=bagfullofsnakes
BFOS
Right, what could possibly prevent it from happening? Consider this: Do organisms change? That is, when organisms reproduce, do they make perfect copies of themselves?

THEM
Well...no...

BFOS
OK. Now, what about environments? Do environments change, or do they stay the same?

THEM
Um, I'd have to say that environments change.

BFOS
OK then...If (1) organisms do NOT make perfect copies of themselves when they reproduce, and (2) environments do NOT remain consistent, and unchanging, then what...other than an act of god...could prevent evolution from occuring?

What you are doing is repeating Darwin's original deductive argument not for evolution, but for natural selection. You may want to start quoting that summary I posted in the previous post to this one.

Remember, descent with modification is not the same as natural selection. Lamack's method of getting modification in descent would still produce descent with modification (if it were true). So what you are arguing for is not changes in populations, but the validity of natural selection.

As to the quote about prayers and hospitals, the answer is: because both of them work.

 

[bagfullofsnakes]

Why don't you read the rest of Origin and then Ernst Mayr's What Evolution Is before you try telling us what evolution is?

Also, another good book for the layman is "Evolution and the Myth of Creationism: A Basic Guide to the Facts in the Evolution Debate" , by Tim Berra.

The book was written in 1990, so some of the information is a little dated - specifically the section on Human fossils, but with the continual discovery of new fossils in that area, it's not surprising. Other than that, however, the book is fantastic!

It even mentions the protenoid microshperes, which I saw you bring up in a separate thread.

 

[lucaspa]

DrFeelGood: I don't want you to overlook a request I made of you. After looking at the diagram in Chapter 4 of Origin and reading what Darwin had to say about the process of natural selection producing new species being the same process that would eventually produce new families, orders, and classes, please respond to this:

So, Drfeelgood, please show us the brick walls in Darwin's diagram that would stop the process of modification.

After all, you have said that no matter how much modification, birds will still be birds. How would modification stop that so that birds would always be birds. In the process, can you fill us in how penguins are still the traditional birds?

 

[bagfullofsnakes]

What you are doing is repeating Darwin's original deductive argument not for evolution, but for natural selection. You may want to start quoting that summary I posted in the previous post to this one.

Remember, descent with modification is not the same as natural selection. Lamack's method of getting modification in descent would still produce descent with modification (if it were true). So what you are arguing for is not changes in populations, but the validity of natural selection.

As to the quote about prayers and hospitals, the answer is: because both of them work.

(1) I'm not sure I understand. How am I equivocating with natural selection, but missing the point of evolution? Doesn't the point that "organisms do NOT replicate perfectly" imply descent with modification? This directly refers to inheritance, mutation, etc.

(2) I'm not sure I understand your comment about prayers working. What do you mean?

 

[lucaspa]

Also, another good book for the layman is "Evolution and the Myth of Creationism: A Basic Guide to the Facts in the Evolution Debate" , by Tim Berra.

The book was written in 1990, so some of the information is a little dated - specifically the section on Human fossils, but with the continual discovery of new fossils in that area, it's not surprising. Other than that, however, the book is fantastic!

It even mentions the protenoid microshperes, which I saw you bring up in a separate thread.

Berra's book is pretty good, but Mayr's more recent book is better just from the science point. Also, I think Kitcher's book Abusing Science: The Case Against Creationism is better than Berra's. More information and, particularly, more about the history and about philosophy of science.

 

[lucaspa]

(1) I'm not sure I understand. How am I equivocating with natural selection, but missing the point of evolution? Doesn't the point that "organisms do NOT replicate perfectly" imply descent with modification? This directly refers to inheritance, mutation, etc.[/QUOTE}

Not equivocating, but equating descent with modification with natural selection. Those are two separate theories, not one. Natural selection is the means of getting the descent with modification. However, even if natural selection were not the means, you would still have descent with modification. That was the point about Lamarck: Lamarck had a different mechanism to get the modifications.

What I am saying is that you are repeating Darwin's original deductive argument which, of course, wasn't answerable then and isn't now. As long as the premises are accurate, the conclusion is assured.

Go back to Darwin's summary of natural selection. Let's list the premises, the "ifs"

1. "If, during the long course of ages and under varying conditions of life, organic beings vary at all in the several parts of their organization"
2. "if there be, owing to the high geometric powers of increase of each species, at some age, season, or year, a severe struggle for life,"

Now, to the conclusions:

1. "if variations useful to any organic being do occur, assuredly individuals thus characterized will have the best chance of being preserved in the struggle for life"
2. "from the strong principle of inheritance they will will tend to produce offspring similarly characterized. "

Now, what is Natural Selection? "This principle of preservation, I have called, for the sake of brevity, Natural Selection."

You've repeated the deductive argument for natural selection. All well and good. I just don't want you equating natural selection to descent with modification.

(2) I'm not sure I understand your comment about prayers working. What do you mean?

14. Byrd, RC, Positive theraputic effects of intercessory prayer in a coronary care population. Southern Med Jour 1988 81(7):826-29. http://www.godandscience.org/apologetics/smj1.html
15. WS Harris, M Gowda, JW Kolb, CP Strychacz, JL Vacek, PG Jones, A Forker, JH O'Keefe, BD McCallister, A randomized, controlled trial of the effects of remote, intercessory prayer on outcomes in patients admitted to the coronary care unit. Arch Intern Med. 1999;159:2273-2278 http://archinte.ama-assn.org/issues/v159n19/rfull/ioi90043.html
15. http://news.bbc.co.uk/hi/english/health/newsid_1627000/1627662.stm A study at North Carolina
17. http://health.medscape.com/viewarticle/405270 IP for infertile women
18: Dusek JA, Sherwood JB, Friedman R, Myers P, Bethea CF, Levitsky S, Hill PC,Jain MK, Kopecky SL, Mueller PS, Lam P, Benson H, Hibberd PL. Study of the Therapeutic Effects of Intercessory Prayer (STEP): study designand research methods.Am Heart J. 2002 Apr;143(4):577-84.
19: Leibovici L. Effects of remote, retroactive intercessory prayer on outcomes in patients withbloodstream infection: randomised controlled trial.BMJ. 2001 Dec 22-29;323(7327):1450-1.

 

[bagfullofsnakes]

You've repeated the deductive argument for natural selection. All well and good. I just don't want you equating natural selection to descent with modification.

I still don't understand.

I've followed along with you so far, and I appreciate the references to "Origin of Species", but I'm not there yet.

If I've neglected descent with modification, I'm not sure how I've done it. I believe I *understand* it fairly well for a layman, so I am honestly asking, "What have I left out?"

Let me see if I understand you:

(1) Organisms do not create perfect copies of themselves.

You say (Darwin says, apparently) that this is a premise. OK, I'm with you.

(2) Environments are NOT static. That is, they DO change.

Premise #2...I'm still with you...

MY Conclusion: Evolution is the unavoidable consequence.

By evolution, I mean "descent with modification". It IS the point of what I am saying. Given the premises (which are observably true), evolution, i.e, descent with modification, is simply unavoidable.

What am I missing here?

Also, in regards to Byrd's study:


http://www.findarticles.com/cf_0/m2843/2_24/60302608/p1/article.jhtml

http://www.infidels.org/library/modern/gary_posner/godccu.html
The most striking flaw in this study's methodology is one forthrightly acknowledged by Byrd. "It was assumed that some of the patients in both groups would be prayed for by people not associated with the study; this was not controlled for. . . . Therefore, 'pure' groups were not attained in this study." In other words, the focus of the study - prayer - was "not controlled for," except that three to seven intercessors were assigned to pray daily for each patient in the IP group, and none was assigned to the controls. Thus, although unlikely, it is nevertheless theoretically possible that the control group received as many prayers as did the IP group, if not more.

 

[SirKenin]

Well, there are more than two causes for speciation. And we have shown that the statement "the old species dies off" is not true. Species do go extinct, but that is not linked to speciation.

No, you have merely shown that you can dance around in circles and hit a base hit while taking my Knight.

But if variations useful to any organic being do occur, assuredly individuals thus characterized will have the best chance of being preserved in the struggle for life; and from the strong principle of inheritance they will will tend to produce offspring similarly characterized. This principle of preservation, I have called, for the sake of brevity, Natural Selection." [Origin, p 127 6th ed.]

Natural selection is the process responsible for the designs in biological organisms.

I don't want to have to reitirate my previous post to you, but the statements in it hold true. You just worded it in a little more detail, serving only to confuse the issue, so I isolated the important part.

Natural Selection is the process or principle (the latter being Darwins own words) of "self preservation" (according to the wording in your latest post) when a catalyst is present. [edit: The catalyst must be present, else] (Otherwise), there is no need to for an organism to feel the need to preserve itself.

Or, in my previous words

This "natural" process of speciation/evolving invoked by catalyst is called Natural Selection according to the Darwinian Theory of Evolution.

You bounced the puck off the post while you added one frag.