Is Darwin's Theory Of Evolution True? Part Two

[buffalo]

Everything can be explained by evolution. It has to be because evolution had to occur. We just know it, and that is that. No doubts are allowed. That is blind faith.

 

[LeafByNiggle]

LeafByNiggle:

Ender:

Darwinism old and new rejects the possibility of the inheritance of acquired characteristics.

…as it should, since there is no evidence that it happens.

Of course there is evidence (evidence does not constitute proof).

if we accept that environmentally induced phenotypes can be inherited, as recent observations show and which I will discuss in a later section, then we have broken the Weismann barrier, because the germline is no longer isolated from the environment and the organism’s response to it. We have also automatically broken the other neo-Darwinian assumption of random variation because phenotype changes can then guide inheritable variation, at least to some degree, as we have seen in item 2, above. The honest response to this situation is to say that the central tenets of neo-Darwinism are simply no longer valid. (Denis Noble, Emeritus Prof Dept of Physiology, Anatomy, Genetics at Oxford, Fellow of the Royal Society)

This is not evidence. This is somebody saying there is evidence.

(appeal to authority?) That theory has been affirmed by even more serious scientists. (If you can do it so can I)

Here you conflate evidence with proof. The theory has not been “affirmed”.

When I said “affirm” I did not mean “proof.” So no conflating there. I merely countered your claim that evolution is being challenged by many serious scientists with the fact that it is accepted by many more serious scientists. Is that better than “affirmed?”

There is nothing surprising or anti-Darwinian about that. Most mutations are harmful, so it makes sense that the genetic mechanisms would evolve to minimize errors. However some errors do escape repair, and these to lead - very occasionally - to beneficial changes.

This is precisely the “stuff happens” form of Darwinism that accepts everything but explains nothing.

It explains all that it is supposed to explain.

The whole field of microbiology is a problem for neo-Darwinism, since there is no separate germ line, and there is rampant exchange of DNA between species. Evolution is as much dependent on horizontal transfer of DNA as on vertical inheritance. Even the concept of species is a problem. (Noble)

Horizontal gene transfer is not an argument against Darwinism.

 

[edwest211]

The problem can also be stated as the ‘stay on message’ approach where contrary information is dismissed or ignored or downplayed.

 

[buffalo]

Horizontal gene transfer is not an argument against Darwinism.

UH, it sure is. Darwinism is all about the vertical transfer of genes from a common ancestor to its descendants. Darwin was the only known theory. HGT challenges this only known theory.

HGT dies not depend on the ancestor. Organisms contact each other irrespective of ancestry for HGT. Add epigenetics and convergent evolution on top of this and better explanations are now forthcoming.

 

[rossum]

Does this imply that mutations do not occur randomly? If they are not random does that not mean they are caused?

Mutations can be caused by radiation, by certain chemicals and maybe other things. The effect of the mutation is random, but the cause may be known. That is why X-ray technicians in hospitals and in dentists take shelter at a distance so as not to get too high a dose of radiation.

If you look hard enough there are probably some genetic studies on the children of the survivors of Hiroshima, Nagasaki and the Chernobyl accident.

rossum

 

[rossum]

UH, it sure is. Darwinism is all about the vertical transfer of genes from a common ancestor to its descendants. Darwin was the only known theory. HGT challenges this only known theory.

HGT dies not depend on the ancestor. Organisms contact each other irrespective of ancestry for HGT. Add epigenetics and convergent evolution on top of this and better explanations are now forthcoming.

HGT is a problem for Darwinism, narrowly defined, because Darwin himself did not mention it.
HGT is not a problem for the current theory of evolution; it is just one more mechanism that changes gene frequencies in a population. If bacterium A passes a copy of a gene to bacterium B, then the frequency of that gene has increased by one in the bacterium A population. That is well within the ambit of the modern theory of evolution.

Do not confuse Darwin’s writings with the modern theory. Science has advanced a long way since 1859.

rossum

 

[buffalo]

Evos are giving up common descent?

 

[rossum]

Evos are giving up common descent?

Creos do not understand that HGT only applies between Eubacteria and/or Archea. It does not apply between Metazoans. Common descent among Metazoans is well established.

rossum

 

[buffalo]

How a quarter of the cow genome came from snakes

“This type of “horizontal gene transfer” (HGT) is an everyday event for bacteria, which can quickly pick up important abilities from each other by swapping DNA. Such trades are supposedly much rarer among more complex living things, but every passing year brings new examples of HGT among animals. For example, in 2008, Cedric Feschotte (now at the University of Utah) discovered a group of sequences that have jumped between several mammals, an anole lizard, and a frog. He called them Space Invaders.”

How a quarter of the cow genome came from snakes

Genomes are often described as recipe books for living things. If that’s the case, many of them badly need an editor. For example, around half of the human genome is made up of bits of DNA that have copied themselves and jumped around, creating vast tracts of repetitive sequences. The same is...

www.nationalgeographic.com

 

[rossum]

Did you read the article?

They’re also relatively rare—they make up just 2 to 3 percent of our genome.

No big deal, just another variation introduced into the genome of the population.

rossum

 

[Ender]

Do not confuse Darwin’s writings with the modern theory. Science has advanced a long way since 1859.

Since Darwin himself accepted the idea of the inheritance of acquired characteristics it is clear that not all the advances have been positive.

HGT is not a problem for the current theory of evolution; it is just one more mechanism that changes gene frequencies in a population.

The problem with the “current theory of evolution” is that it appears to be at odds with the latest developments in microbiology. The “gene centric” view of evolution ("Richard Dawkins summed it up when he wrote that genes are “sealed off from the outside world.”) is encountering difficulties.

Spalding, Baldwin, and the adaptability driver. This is a phenomenon usually known as the “Baldwin effect,”[25] or “adaptability driver”—which is the term I prefer.[26] Organisms can choose new niches for themselves and their descendants.[27] Moving to a new niche can change the course of evolution even with no mutations whatsoever. That choice is a physiological characteristic of the phenotype, not a change in DNA. So how can it change the course of evolution? The answer is surprisingly simple. In a wild population in which individual genomes are not identical, the combinations of alleles in the adventurous organisms discovering new niches will be favored. That is an evolution of the genome by combinatorial selection, not selection of new random mutations. Such selection can lead to inherited novelty, as Waddington showed so clearly in his work on fruit flies. (Noble)

 

[Ender]

No big deal, just another variation introduced into the genome of the population.

The inheritance of an acquired characteristic would also be “just another variation introduced into the genome.” Would that also be “no big deal”?

 

[Ender]

This is not evidence. This is somebody saying there is evidence.

I’m not sure what you would accept as evidence. How about this:

Conrad Waddington and genetic assimilation. The Weismann Barrier was based on some experiments in which the amputation of tails in mice did not lead to mice being born with no tails. But surgical mutilation is not a test for Lamarckian forms of inheritance. Waddington performed the experiments that more successfully tested for the inheritance of acquired characteristics by using environmental manipulations that played into natural plasticity in fruit fly populations. But orthodox neo-Darwinists dismissed Waddington’s findings as merely an example of the evolution of phenotype plasticity. That is what you will find in many of the biology textbooks. I think that is to misrepresent what Waddington showed. Of course, plasticity can evolve, and that itself could be by a neo-Darwinist or Darwinist or any other mechanism. But Waddington was not simply showing the evolution of plasticity in general; he was showing how it could be exploited to enable a particular acquired characteristic in response to an environmental change to be inherited and become assimilated into the genome. (Denis Noble)

However some errors do escape repair, and these to lead - very occasionally - to beneficial changes.

The only example in history where noise introduced into a signal produces beneficial changes is neo-Darwinian evolution. In every single other example it simply degrades the original. This is the “and then a miracle happens” explanation.

 

[Aloysium]

As stated elsewhere, the issue isn’t the impact of mutations on adaptation but rather that they could ever result in the complexity of life we see around us.

But I was interested in reference source 23 The distribution of fitness effects of new mutations since it might provide some of the background research for the overview in the Wiki article. Unfortunately, it is 10 years old, but should still be relevant.

Some of what I got from it were the following:

• the research is mainly conducted using microscopic organisms
• the fitness effects of spontaneous mutations is often not possible, and mutations are induced by either transposable element insertion or a chemical mutagen.
• relatively few of the nondeliterious mutations that are not effectively neutral are advantageous.
• they don’t indicate what operational definition they use to measure advantage
• the example they provide as indicating the possibility of evolutionary change through mutation, they admit measured substitution rates rather than mutation rates. Those analyses therefore cannot tell us directly about the frequency of advantageous mutation. They speculate that a series of mutations could be the equivalent of a substitution.
• the DFE (distribution of fitness) of advantageous mutations seems to be exponential, which means that the number of unfit organisms is high and as fitness increases, the number of organisms drops very quickly and tapers off to zero.
• for more complex organisms, mutations tend to have little effect, even when they are deleterious suggesting to me that it is more unlikely that random mutations would lead to the diversity seen in nature.
• they point to comparative methods using DNA sequence data as a way to determine the pattern of polymorphism in a species and thereby estimate the effects of mutations and infer their overall fitness consequences within the environment in which the species evolved. Here they are again talking about adaptation, not evolution as a method for creation. Such data could not be used to validate the standard theory of evolution since its analysis is based on the assumption that there was a common ancestor rather than their having simply been a common design. It would be a circular argument.

 

[Aloysium]

Have you come across this article?

Lamarckian theories about the influence of the environment were largely abandoned after scientists discovered that heritable traits are carried on the genes encoded by our DNA. A recent study, however, published by neuroscientists Junko A. Arai, Shaomin Li and colleagues at Tufts University, shows that not only does the environment an animal is reared in have marked effects on its ability to learn and remember, but also that these effects are inherited. The study suggests that we are not the mere sum of our genes: what we do can make a difference.

Could Living in a Mentally Enriching Environment Change Your Genes?

When mice are exposed to enriched environments, their offspring can overcome genetic defects that impair long-term memory.

www.scientificamerican.com

 

[edwest211]

A common design for land creatures exists. It is observable. If a designer used the same basic building blocks: head, upper and lower torso and four limbs, including wings, then I could put those building blocks into a 3-D render and build whatever land-dwelling creature I wanted, from large to small. The genetic instructions would be similar and scaled as needed. From the largest to the smallest dog, for example.

 

[Rau]

If that design is particularly amenable to the environmental circumstances on planet earth (and presumably it is) it would not be surprising to see it, regardless of which processs (variously discussed on this thread) you imagine led to it.

 

[Techno2000]

By contrast, Darwin’s theory posited that traits evolve as part of a random, gradual process. The giraffes that happened to have been born with longer necks thanks to a random genetic mutation were better fed and thus healthier than their shorter-necked counterparts, making them more likely to live long enough to breed and pass on this trait.

So a giraffe is a freak of nature that got lucky finding food ?

 

[LeafByNiggle]

LeafByNiggle:

This is not evidence. This is somebody saying there is evidence.

I’m not sure what you would accept as evidence. How about this:

Conrad Waddington and genetic assimilation. The Weismann Barrier was based on some experiments in which the amputation of tails in mice did not lead to mice being born with no tails. But surgical mutilation is not a test for Lamarckian forms of inheritance. Waddington performed the experiments that more successfully tested for the inheritance of acquired characteristics by using environmental manipulations that played into natural plasticity in fruit fly populations. But orthodox neo-Darwinists dismissed Waddington’s findings as merely an example of the evolution of phenotype plasticity. That is what you will find in many of the biology textbooks. I think that is to misrepresent what Waddington showed. Of course, plasticity can evolve, and that itself could be by a neo-Darwinist or Darwinist or any other mechanism. But Waddington was not simply showing the evolution of plasticity in general; he was showing how it could be exploited to enable a particular acquired characteristic in response to an environmental change to be inherited and become assimilated into the genome. (Denis Noble)

This is still someone saying there is evidence. But it is far from evidence because there is no mention of a specific characteristic or the description of an experiment. Evidence would be a single instance of a characteristic of a organism that is acquired through experience passed on to the offspring genetically (not through the parent teaching the child.) Or do I have a mistaken idea of what an acquired characteristic means?

However some errors do escape repair, and these to lead - very occasionally - to beneficial changes.

The only example in history where noise introduced into a signal produces beneficial changes is neo-Darwinian evolution.

Why “neo?” Isn’t this what happens in plain old garden variety Darwinian evolution?

In every single other example it simply degrades the original. This is the “and then a miracle happens” explanation.

I see. You are omitting natural selection. Of course mutations are generally harmful or neutral. But when you add natural selection to the process, you favor the mutations that are beneficial. Just because you never saw a beneficial mutation arising by chance does not mean it can’t happen. In fact, given enough instances of mutations, it has to happen.

 

[buffalo]

Because something is possible does not mean it is probable.