Has evolution done stopped?

[SirKenin]

I'll give you the benefit of the doubt and assume that you were misunderstanding what you read rather than trying to be dishonest here. You quoted Darwin as follows:



Even a cursory examination of this quote makes it clear that the word "inevitably" is used to describe the fact that his conclusion follows his premises. In no way does the word, as it is used here, ascribe inevitability to the extinction of ancestral species.

All Darwin is saying here is that when one studies the processes involved, one "inevitably" concludes that, just as new species will appear, other species will become extinct. Only by completely mangling that sentence could you accuse Darwin of stating that extinction of ancestral species is "inevitable."

-brett

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.

 

[SirKenin]

Why does this make me think of the "if humans evolved from apes, why are apes still around?" argument.

According to Darwins theory, on at least two points, they shouldn't be

a) natural selection
b) missing link (and don't tell me they exist. Every single one has proven to be a hoax. Even the supposed "transitions" between various species of man have proven to be a hoax)

 

[Jet Black]

a) this shows a profound misunderstanding of Darwin's theory. there are still niches which are fine for apes, so why would they evolve in those niches because there is no real evolutionary pressure on them.
b) there are enough links in various threads to rubbish this claim.

 

[SirKenin]

a) this shows a profound misunderstanding of Darwin's theory. there are still niches which are fine for apes, so why would they evolve in those niches because there is no real evolutionary pressure on them.
b) there are enough links in various threads to rubbish this claim.

Where there is no evolutionary pressure on them, there is no reason for them to evolve. Come to think of it, there was never any evolutionary pressure for an amoeba to develop into a fish... A fish to develop into a lizard.. I think with the concept initiated in your post we can rubbish the entire theory of evolution

 

[notto]

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.

Still looking for the MUST. Darwin made observations that hold true but he never said that species MUST become extinct, only that the DO become extinct. There is a distinction in these two statements. Darwin doesn't use the words MUST and does not state that ALL species MUST become extinct as new ones are formed.

"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."

The Origin of Species
Charles Darwin
Chapter 4 - Natural Selection

 

[SirKenin]

Still looking for the MUST. Darwin made observations that hold true but he never said that species MUST become extinct, only that the DO become extinct. There is a distinction in these two statements. Darwin doesn't use the words MUST and does not state that ALL species MUST become extinct as new ones are formed.

"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."

The Origin of Species
Charles Darwin
Chapter 4 - Natural Selection

And that's fair, but it specifies "foreign species". That's what I noticed when I read it last night. To me, foreign species is an "introduced" species. Not a species developed from Natural Selection. Now, with my VERY limited knowledge of this stuff (and it's EXTREMELY limited), my thoughts were that this sentence can not be included in his generalizations that all species "must" become extinct as a part of the process of natural selection. (and natural selection, incidentally, literally means survival of the fittest. By very definition the weak must be extinguished.)

Do correct me if I'm wrong though (and that's quite possible)

 

[lucaspa]

The humans in your examples are still humans lucaspa. A bird has always been a bird. And we've been through this before. Darwin said the old species must inevitably die off. There are no maybes.

The classic sidestep of creationists at this point. First they ask for SPECIATION and then they give examples like "bird". You do know what "bird" is, don't you? It's the colloquial name for an entire CLASS in the taxonomic ranking system -- Aves -- composed of thousands of species. So now you are asking a completely different question: trace multiple speciation events to give a class. This has been done in the fossil record, but since these speciation events each requires years even in fast reproducing species, it has not yet been observed in real time.

However, it is unnecessary. After all, the ONLY biological REALITY is the SPECIES. Higher taxa like "birds" are simply human groupings of species. So once you have species, you are done. Evolution. To get a "higher taxa" you simply have multiple speciation events spread thru time.

I never said that the populations of H. sapiens had diverged to the point of speciation. I simply said that they had STARTED to so diverge, with indications of incipient reproductive isolation. IF the present trends continue and gene flow (breeding outside the population) does not happen, then they will be a new species in the genus Homo.

Can you quote where Darwin said this? I can't find it searching the phrase you gave me on the citable Darwin site. http://pages.britishlibrary.net/charles.darwin/

I remain unconvinced.

I never thought otherwise. You have already indicated that there is no evidence that could possibly convince you. However, that is your problem, not the data's.

As for the DNA. I don't know which genetic code or sequence it is, but I can find out. I can tell you that it is what allows hair to become certain colors, but it doesn't allow hair to become a bird.

But it can allow hair to become something else that is not hair. You mentioned birds. Recent discoveries have shown the genetic changes that occurred to convert a scale to a feather, so that you can go from reptile/dino to bird.

2. RO Prum and AH Brush, Which came first, the feather or the bird? Scientific American, 84-93, March 2003.
3. Sawyer RH, Salvatore BA, Potylicki TT, French JO, Glenn TC, Knapp LWJ, Origin of feathers: Feather beta (beta) keratins are expressed in discrete epidermal cell populations of embryonic scutate scales. Exp Zool 2003 Feb 15;295B(1):12-24
4. Zou H, Niswander L , Requirement for BMP signaling in interdigital apoptosis and scale formation. Science 1996 May 3;272(5262):738-41

These papers make use of a new discipline called, for short "evo-devo", that uses developmental biology to study evolution. From the last paper: "Expression of dnBMPR in chicken embryonic hind limbs greatly reduced interdigital apoptosis and resulted in webbed feet. In addition, scales were transformed into feathers."

So, we don't always need a new protein, but simply different developmental expression of some proteins, in this case bone morphogenetic protein, to convert a scale to a feather.

 

[Jet Black]

Where there is no evolutionary pressure on them, there is no reason for them to evolve. Come to think of it, there was never any evolutionary pressure for an amoeba to develop into a fish... A fish to develop into a lizard.. I think with the concept initiated in your post we can rubbish the entire theory of evolution

no, because your point assumes you know all the conditions of the whole planet all the time. you blatantly don't, and neither do I. the fact of the matter is that there are fish, and there are reptiles, so if you accept evolution there must at some point have been something that preferentially selected for ´particular characteristics of an organism, that spread and eventually arrived at the fish.

 

[SirKenin]

The classic sidestep of creationists at this point. First they ask for SPECIATION and then they give examples like "bird". You do know what "bird" is, don't you? It's the colloquial name for an entire CLASS in the taxonomic ranking system -- Aves -- composed of thousands of species. So now you are asking a completely different question: trace multiple speciation events to give a class. This has been done in the fossil record, but since these speciation events each requires years even in fast reproducing species, it has not yet been observed in real time.

However, it is unnecessary. After all, the ONLY biological REALITY is the SPECIES. Higher taxa like "birds" are simply human groupings of species. So once you have species, you are done. Evolution. To get a "higher taxa" you simply have multiple speciation events spread thru time.

I never said that the populations of H. sapiens had diverged to the point of speciation. I simply said that they had STARTED to so diverge, with indications of incipient reproductive isolation. IF the present trends continue and gene flow (breeding outside the population) does not happen, then they will be a new species in the genus Homo.

Can you quote where Darwin said this? I can't find it searching the phrase you gave me on the citable Darwin site. http://pages.britishlibrary.net/charles.darwin/



I never thought otherwise. You have already indicated that there is no evidence that could possibly convince you. However, that is your problem, not the data's.



But it can allow hair to become something else that is not hair. You mentioned birds. Recent discoveries have shown the genetic changes that occurred to convert a scale to a feather, so that you can go from reptile/dino to bird.

2. RO Prum and AH Brush, Which came first, the feather or the bird? Scientific American, 84-93, March 2003.
3. Sawyer RH, Salvatore BA, Potylicki TT, French JO, Glenn TC, Knapp LWJ, Origin of feathers: Feather beta (beta) keratins are expressed in discrete epidermal cell populations of embryonic scutate scales. Exp Zool 2003 Feb 15;295B(1):12-24
4. Zou H, Niswander L , Requirement for BMP signaling in interdigital apoptosis and scale formation. Science 1996 May 3;272(5262):738-41

These papers make use of a new discipline called, for short "evo-devo", that uses developmental biology to study evolution. From the last paper: "Expression of dnBMPR in chicken embryonic hind limbs greatly reduced interdigital apoptosis and resulted in webbed feet. In addition, scales were transformed into feathers."

So, we don't always need a new protein, but simply different developmental expression of some proteins, in this case bone morphogenetic protein, to convert a scale to a feather.

Oh, I see how this works lucaspa... I can't play a game of soccer with you, because you keep moving the goal posts and swapping the balls.

"a new discipline called, for short "evo-devo"..."

I'm not talking about new disciplines... When you've made up your mind what game you want to play, perhaps we can discuss this again.

 

[Jet Black]

(and natural selection, incidentally, literally means survival of the fittest. By very definition the weak must be extinguished.)

Do correct me if I'm wrong though (and that's quite possible)

remember that "weak" in this context merely means poor adaptation to the environment (and that environment includes competing organisms)

 

[notto]

And that's fair, but it specifies "foreign species". That's what I noticed when I read it last night. To me, foreign species is an "introduced" species. Not a species developed from Natural Selection. Now, with my VERY limited knowledge of this stuff (and it's EXTREMELY limited), my thoughts were that this sentence can not be included in his generalizations that all species "must" become extinct as a part of the process of natural selection. (and natural selection, incidentally, literally means survival of the fittest. By very definition the weak must be extinguished.)

Do correct me if I'm wrong though (and that's quite possible)

All Humans Do pick their noses.
All Humans MUST pick their noses.

Notice the difference in these two statements?

If parent species do not become extinct even after a new species arises from their population due to migration and isolation, this does not falsify evolution.

This point can be demonstrated by observing ring species.


Ring Species
More on Ring Species

 

[lucaspa]

Where there is no evolutionary pressure on them, there is no reason for them to evolve. Come to think of it, there was never any evolutionary pressure for an amoeba to develop into a fish... A fish to develop into a lizard..

That's not true. The pressure, always, comes from the environment. If the environment stays constant for the population, then purifying selection will keep the population constant.

BUT, any part of the population that becomes isolated either geographically OR thru a new ecological niche will face a different environment. Then the subpopulation will face directional selection (what you call "evolutionary pressure") and will adapt to the new environment, becoming morphologically and genetically distinct from the old population -- a new species.

Now, the original population will stay happy in the old niche. When you talk amoeba to fish and fish to lizard what you are talking about are hundreds of speciation events spread thru time. Also, you are talking about only ONE population of amoeba that diverged originally and only ONE population of ONE species of fish that went on to become amphibians and then ONE population of ONE species of amphibian to become reptiles.

The other hundreds of species of amoeba, fish, and amphibians did not face those new environments and directional selection.

The problem I see is that you don't use the term "species" properly. You are using the colloquial names for entire GROUPS of species as though they were one species.

 

[SirKenin]

no, because your point assumes you know all the conditions of the whole planet all the time. you blatantly don't, and neither do I. the fact of the matter is that there are fish, and there are reptiles, so if you accept evolution there must at some point have been something that preferentially selected for ´particular characteristics of an organism, that spread and eventually arrived at the fish.

Ok. I must admit that if you can buy all that, you have more faith than most Christians.

Now it's my turn. Show me the evidence. Show me the catalysts. Why would a fish suddenly decide the water isn't good enough for them, yet remain in there none the less?

And let's not start off with a game of soccer, only to end up playing a game of chess.

 

[lucaspa]

There have probably been examples where a new species arises from a parent population through isolation and itself becomes extinct while the parent population continues to survive.

Here is an example for you:

1. Williamson, PG, Paleontological documentation of speciation in cenozoic molluscs from Turkana basin. Nature 293:437-443, 1981.

What once was one large lake became several small lakes during a 20,000 year long dry period. Each lake evolved a new species of mollusc in it adapted to the special conditions of that particular lake. The original species persisted in ONE of the lakes. When the dry period was over and the lakes merged again into one large lake, the original species drove all the derived species extinct.

 

[SirKenin]

remember that "weak" in this context merely means poor adaptation to the environment (and that environment includes competing organisms)

I get the feeling I'm getting caught in circular logic...

What Darwin is saying is that there is a catalyst that causes old species to speciate. He calls this process Natural Selection. As a result of this process, the old species must die off. There was a reason why they had to speciate to begin with. If there wasn't, there would be no need, and they wouldn't have. Organisms don't just speciate for no reason. You've even said that in your posts.

There are only two reasons for an organism to speciate

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

Now, what you and the rest of you can do is figure out where all your logic fits into what Darwin is saying, and stop dragging me around in circles. lol

 

[Jet Black]

Ok. I must admit that if you can buy all that, you have more faith than most Christians.

Now it's my turn. Show me the evidence. Show me the catalysts. Why would a fish suddenly decide the water isn't good enough for them, yet remain in there none the less?

It's not faith, it is just accepting it, because that is what the evidence looks like.

they don't suddenly decide "oh let's go over there" there could be a multitude of reasons; lack of food forces creatures to spread further away from what was before a good food source, some sort of geological event, some getting lost, some organisms getting carried by others and so on. natural pressures in otherwords, stuff in the environment that forces them out of their current situation into another where they may not be quite so well adapted.

 

[notto]

Ok. I must admit that if you can buy all that, you have more faith than most Christians.

Now it's my turn. Show me the evidence. Show me the catalysts. Why would a fish suddenly decide the water isn't good enough for them, yet remain in there none the less?

And let's not start off with a game of soccer, only to end up playing a game of chess.

1) New food sources to out compete existing fish (flying or near shore insects
2) Better survivability of eggs from predators
3) Ability to migrate from one pool of water to another when the food runs out or during a dry spell (this activity exists in current species)


The fish doesn't decide anything. They simply survive as best they can. If one has a feature that gives it a slight advantage (such as being able to crawl a bit further up on land or survive a bit longer out of water during a dry spell), it will produce more offspring with these inheritable traits.

 

[lucaspa]

Now it's my turn. Show me the evidence. Show me the catalysts. Why would a fish suddenly decide the water isn't good enough for them, yet remain in there none the less?

First, there is no "decision" by the fish. Let's get that teleological idea out right now.

Instead, let's look at mudskippers today. They live in streams in Africa that go dry in the dry season. So, they live in the water when the streams have water. BUT, when the streams dry up, they are forced to travel across land to a new stream to find food. Thus their front fins are adapted to serve as partial legs to let them move on land and they have primitive lungs to allow them to breathe air.

Now, we can construct an evolutionary history of mudskippers. They originally were completely "fish" but when the climate changed and streams began to dry up, those fish lucky enough to be able to flop to a new stream survived and those that couldn't died. The lucky fish had stonger fins to move on land and an ability to survive out of water longer than the unlucky ones in the population. The lucky ones passed on the alleles to their offspring. Soon all the fish in the population had those alleles.

Now, when a new allele appeared by mutation that allowed stronger fins or more ability to breathe air, those lucky individuals outcompeted the ones with the old alleles: they could get to streams further away. Again, soon ALL the members of the population had those new alleles.

And the accumulation of ability continued generation to generation. The eventual result is the mudskipper -- a new species from that original species back in time.

Always remember the ACCUMULATION of traits of natural selection.

 

[Jet Black]

What Darwin is saying is that there is a catalyst that causes old species to speciate. He calls this process Natural Selection. As a result of this process, the old species must die off. There was a reason why they had to speciate to begin with. If there wasn't, there would be no need, and they wouldn't have. Organisms don't just speciate for no reason. You've even said that in your posts.

see lucaspa's post immediately above yours.

 

[lucaspa]

Without evidence, this is merely conjecture. It is only becoming older as the theory of evolution is running out of time and options.

Actually, there is more than enough time. Recent experiments show that natural selection can work MUCH faster -- up to 10,000 TIMES faster -- than seen in the fossil record.

2. Reznick, DN, Shaw, FH, Rodd, FH, and Shaw, RG. Evaluationof the rate of evolution in natural populations of guppies (Poeciliareticulata). Science 275:1934-1937, 1997. The lay article isPredatory-free guppies take an evolutionary leap forward, pg 1880.

So, the earth COULD be as young as 46 million years and there would be enough time for natural selection to produce the diversity of life on the planet.

I'm afraid your circular logic also doesn't hold on the evidence. The people who figured out the age of the earth did so independently of evolution and without consideration of the time required for evolution.