Darwin re-visited

[Michaelangelica]

And we'll reciprocate with pleasure. :shrug:

(not really, but it sounded good :shade: )

 

LOLlololo:)

Thank you for your tolerance and good humour

 

Sorry I don't know what i am doing here.

"I know nothing "-Manuel Faulty Towers.

 

As I said, I FEEL things are not right or enough.

That is not science.

 

You can make anything "fit' into the "natural selection" model after the event.

Can you do it before the event?

Where is the predictive power of Natural Selection?

 

I am not saying NS is not a great theory but for me , personally, it is not enough.

[freeztar]

You can make anything "fit' into the "natural selection" model after the event.

Can you do it before the event?

Where is the predictive power of Natural Selection?

NS is not a predictive concept, it is descriptive.

 

Not every adaptation fits into NS. It deals strictly with organism fitness.

 

I am not saying NS is not a great theory but for me , personally, it is not enough.

 

Which part of it do you find lacking?

[Pyrotex]

NS is not a predictive concept, it is descriptive.

Not every adaptation fits into NS. It deals strictly with organism fitness.

Which part of it do you find lacking?

Lessee here... :eek:

 

NS is predictive in somewhat the same sense that the differential equations of atmospheric thermodynamic behavior are predictive. You can predict rain in Houston is more or less likely this weekend, but you can't say anything about the liklihood of rain in Houston on October 29, 2108.

 

Does that mean weather forecasting is NOT a science? No.

 

NS includes many "forces" pushing evolution one way or another. The most interesting to me is Sexual Selection (SS). That's what makes for gorgeous peacock tails, even though the tails arguably make the male birds LESS fit, physically.

 

Then you got co-evolutionary forces. Certain bees and orchids evolve TOGETHER. :doh:

[REASON]

Lessee here... :eek:

 

NS is predictive in somewhat the same sense that the differential equations of atmospheric thermodynamic behavior are predictive. You can predict rain in Houston is more or less likely this weekend, but you can't say anything about the liklihood of rain in Houston on October 29, 2108.

 

A minor semantical clarification here:

 

Natural Selection does not predict. It is simply a process.

 

People, in observation of natural processes, may make limited predictions.

 

Good discussion. Pyro, I always enjoy reading your posts on this topic. You have great passion for it. :doh:

[Michaelangelica]

Science, for me, is the making of models that predict-

as in E=MC2

 

For explanations, I look up Encyclopaedia Britannica or now, Wiki.

I agree NS explains a lot, but it is incomplete unless it can predict as well as explain.

[Pyrotex]

Science, for me, is the making of models that predict...I agree NS explains a lot, but it is incomplete unless it can predict as well as explain.

Well, okay, I understand you. And I have some sympathy for that POV.

 

But, there ARE natural processes in the Cosmos that have the property that they are inherently unpredictable, even when the "equations of behavior" are totally understood. :cup: When this happens, it is always the case that the equations are non-linear differential equations.

 

The science of Chaos is defined as the study of non-linear differential equations. The most obvious {to Earth-bound humans} example is, in fact, weather prediction. We can in fact predict the weather out to several days, sometimes a week. Beyond that, the uncertainty in initial conditions makes prediction rather pointless.

 

Every time I have said that {in other contexts} before, somebody always comes back: "Well, if we had faster computers... If we had infinite knowledge of the initial conditions... If we understood better... One day when all the laws of physics are known... Etc...."

 

But, NO. Non-linear differential equations are the bugaboos of Math and Physics. And almost all the really interesting phenomena of science {including evolution, specifically prediction of evolutionary paths} is dominated by non-linear differential equations.

 

Read something about Chaos Theory. Even Jehovah God Almighty his own sweet self CANNOT predict next month's weather. Sorry. And he CANNOT predict how marmosets are going to look 50,000,000 years from now.

 

{Assuming he keeps his cotton-picking fingers out of the soup for that long} :eek: :doh: :cup: :cup:

[freeztar]

When I said NS was descriptive, not predictive, what I meant was that NS is a process (thanks for the clarification Reason) that is not future determinant. We can, and do, look at changes in NS through the past and make predictions about how the changes influence the present. I did not mean to imply "predictive" in the scientific sense, but in the prognostic sense. :doh:

 

Of course, NS can also be tested like other scientific theories by making a prediction and testing it. Kettlewell's experiments with peppered moths, which showed that NS from industrial melanism caused the peppered moth's adaptation, is a classic example of this.

 

So yes, NS can be predictive, but not in the Nostradamus-futuristic sense (not with any kind of accuracy anyways). :eek:

[REASON]

Science, for me, is the making of models that predict-

as in E=MC2

 

For explanations, I look up Encyclopaedia Britannica or now, Wiki.

I agree NS explains a lot, but it is incomplete unless it can predict as well as explain.

 

While it may be impossible to predict the results of natural selection over long periods of time for any given species, it is possible to use the principles of Natural Selection in a controlled environment to generate a predictable result such as in Pyro's dark cow example, or Sagan's Samurai crabs (Cosmos).

 

Why wouldn't the predictability of Artificial Selection be qualified as scientific evidence for the processes of Natural Selection?

[Pyrotex]

...Why wouldn't the predictability of Artificial Selection be qualified as scientific evidence for the processes of Natural Selection?

DING! DING! DING!

 

We Have a Winner!!!! :cup: :cup: :lol:

 

That is EXACTLY what Darwin did in his first book, Origen of Species!!!

 

Much of the book is what he learned interviewing dog breeders, pigeon fanciers and cattle breeders. He showed that dogs as different as Chihuahua and Great Dane came from common stock through the artificial pressure of breeders. If turned loose in the wild, those two dogs are very unlikely to breed, and indeed, would seek different ecosystems to find their food and dens. Therefore, they would probably become different species over sufficient time.

 

TA-DAHHHHHH!!! :eek: :doh: :cup:

[TruthChaser]

Hey everyone.. hey again Pyrotex!

 

Just dropped in... I must admit I haven't had time today to read the whole thread so please forgve me if I repeat something or go over something you've been over... but... NS is a great explanation of what we see happening. My only reservation is that it does not prove evolution toward a higher species. I mean, NS is merely the reuse, mutation, or loss of existing DNA and it never means new DNA is added or increased to grow (so to speak) new bilogical features. Sure, you can have dogs changing the way their species adapts, to a point where that dog's descendants represent a new species (after the orginal kind) but the dog would not become a different kind of species (say a cow or a horse, or a bird etc). This may be obvious but I am just trying to reconcile my own thought patterns so please be patient with me.

 

So, while I love and support the wonderful idea of Natural Selection, I wonder how the other side of evolution is supported in the light of DNA?

[REASON]

NS is a great explanation of what we see happening. My only reservation is that it does not prove evolution toward a higher species. I mean, NS is merely the reuse, mutation, or loss of existing DNA and it never means new DNA is added or increased to grow (so to speak) new bilogical features.

 

On what do you base this notion?

 

 

Sure, you can have dogs changing the way their species adapts, to a point where that dog's descendants represent a new species (after the orginal kind) but the dog would not become a different kind of species (say a cow or a horse, or a bird etc).

 

Simply stated, dogs are still dogs no matter what their variety or breed.

 

But as the Chihuahua and the Great Dane go off and evolve naturally; adapting to their own environments each in their own way; facing the forces of competition for survival each in their own way; changing over time genetically as they adapt to their own circumstances and conditions; at what point would it be reasonable to suggest that they had become separate species that showed evidence of a common ancestor? How many years or lifetimes do you think it might take before such a conclusion may be made? What would stop this process from continuing on-and-on to the point at which the two species have become increasingly distinct, and start to produce other branches of species, each having the same common ancestor?

 

The issue you're getting stuck on here is time. You have to be willing to understand that diversity to the point of defining a new species requires enough time to do so. But the evidence of common ancestry often remains.

 

Dogs may not be cows, but dogs and cows are both animals, and quadrupeds, and mammals, and vertebrates, and have tails. I'd be willing to go out on a limb and suggest that they have a common ancestor that, from the standpoint of an evolutionary timeline, isn't in the too distant past. Common ancestry is revealed to us by the fossil record. And while there are many obvious gaps, there is plenty of evidence to confirm the process.

 

Among evolutionary scientists, the people that know the most about the subject, the evolution of living organisms to distinct and higher species is a natural fact.

[Symbology]

 

Much of the book is what he learned interviewing dog breeders, pigeon fanciers and cattle breeders. He showed that dogs as different as Chihuahua and Great Dane came from common stock through the artificial pressure of breeders. If turned loose in the wild, those two dogs are very unlikely to breed, and indeed, would seek different ecosystems to find their food and dens. Therefore, they would probably become different species over sufficient time.

 

Actually they would just become one species because most Chihuahuas require a cesarean section to survive having puppies. So pretty much without humans, Chihuahuas don't have a chance.

 

Though I suppose now that I think about it, I bet some small percent of them would survive, and then that group would continue on. I guess we are just currently witnessing the results of the owners artificial inbreeding.

[Symbology]

Dogs may not be cows, but dogs and cows are both animals, and quadrupeds, and mammals, and vertebrates, and have tails. I'd be willing to go out on a limb and suggest that they have a common ancestor that, from the standpoint of an evolutionary timeline, isn't in the too distant past. Common ancestry is revealed to us by the fossil record. And while there are many obvious gaps, there is plenty of evidence to confirm the process.

 

Here you go, from Nature.com Congratulations, Reason, you get the prize!

 

[Symbology]

NS is merely the reuse, mutation, or loss of existing DNA and it never means new DNA is added or increased to grow (so to speak) new bilogical features. Sure, you can have dogs changing the way their species adapts, to a point where that dog's descendants represent a new species (after the orginal kind) but the dog would not become a different kind of species (say a cow or a horse, or a bird etc). This may be obvious but I am just trying to reconcile my own thought patterns so please be patient with me.

 

So, while I love and support the wonderful idea of Natural Selection, I wonder how the other side of evolution is supported in the light of DNA?

 

Viruses do a nice job of taking genetic code from one species and inserting it into the new host. Sometimes the new host survives, and sometimes it does not. For example bird flu can bring genetic code from the birds into the infected humans. For those humans that survive they can then pass on this new code to their offspring.

 

Also our cells themselves create genetic mutation by a process called Cassette mutation, which is basically like our own little mad scientist lab, doing plug and play experimentation along the lines of what us computer programmers call "modular programming". There could be sequences for eye color, for example, that can be pulled out and replaced with another eye color sequence that has the same interface, but a different interior sequence. That is overly simplistic - but it is roughly how it works. So that other modules that serve the same basic purpose can be tried out.

 

 

Sometimes it doesn't go so well. For example Cystic Fibrosis involves a cassette swap out of ATP-binding cassette sub-family C.

 

[TruthChaser]

Thanks for all the responses...

 

Ok... first of all, time is not the issue I have. Some instances of NS can happen very quickly (over hundreds of years instead of millions).

 

The issue I have is DNA and how does an animal evolve into a higher, differently gentically coded species... like the dog to cow analogy? (I'm using that one because that's where the conversation has been). I see the chart but the chart doesn't explain to me how new information is added to the genetic code.

 

The virus explanantion is an interesting thing. Thank you for that. I can see how, if the virus deposited new DNA into the recipient's genetic code it may be passed onto offspring. How would you speculate that information would do something as dramatic as give a dog udders (to become a cow) or the amazingly complex digestive system of a cow? All I am saying is that evolution proposes that an animal can evolve into a higher species but I am asking how this is done genetically (unless those viruses have some pretty amazing codes and why on earth aren't the viruses making use of such spectacular information themselves?)

 

As for the mutation theory... mutation is about existing DNA changing... usually doesn't cause such a positve outcome. Quote: "In virtually every instance, rather than adding new information, mutations destroy genetic information or corrupt the way it can be expressed - the original genes are damaged and no longer able to perform their original function." and "Unfortunately for the theory of evolution, no mutation has yet been shown to add the sort of information to a creature's DNA the theory requires."(Dr David Catchpoole PhD physiology).

 

Biophysicist Lee Spetner did an examination of mutational changes and in all the cases discovered that there was actually a loss of genetic information rather than an addition.

 

So, while I fully understand and appreciate natural selection and all it can entail, time is no issue, I do have serious reservations, genetically speaking, about evolution (which I believe is not to be confused with Natural Selection).

 

TC

[freeztar]

Hey TC,

Here's a good article on retroviruses and how they have contributed to our genetic code:

Annals of Science: Darwin’s Surprise: Reporting & Essays: The New Yorker

[freeztar]

So, while I fully understand and appreciate natural selection and all it can entail, time is no issue, I do have serious reservations, genetically speaking, about evolution (which I believe is not to be confused with Natural Selection).

 

I think the above pretty much sums up the confusion.

 

Natural selection is one component of evolution. Another component of evolution, which probably holds the answers you are looking for, is speciation.