How accurate is the theory of evolution by natural selection of darwin?

[swansont]

why fossil record don't show intermediary steps of development?

The fossil record does. So this question is based on incorrect information.

 

 

but still there is some match of DNA between man and spider monkey. isn't it? the degree shows that. but it should be no match between man and spider monkey.

'

Why shouldn't there be? We share a common ancestor at some time in the past and as a result have lots of common physical features. Any basic encoding for two arms and two legs, lungs, a heart, etc. would be largely the same. Our similarities with a spider monkey far outweigh our differences.

[studiot]

1)

I am no expert in life sciences, even I have heard of Darwin's Finches.

I will leave you to do some research about this.

 

2)

I understand Mendel was a contemporary of Darwin and published his (query more mathematical) rules not long after Origin.

Again I will leave you to look up the comparison.

Edited August 5, 2014 by studiot

[Ophiolite]

 

i want to verify the validity of a scientific theory. i don't think that one should not verify a theory becoz some authority has made the theory.

Good luck with that wish.

 

In order to verify the validity of the theory you have two options:

 

1. You can devote the next forty years of your life to gathering information, carefully assessing it, testing it against reality, adapting your thinking accordingly, then - when you have the basics reasonably well established - you can look for weaknesses in the current theory and probe at those for a couple of decades. When no weaknesses are revealed you may provisionally accept the theory as valid.

2. Alternatively you could consider that tens of thousands of researchers have done this for you and all you need to do is to satisfy yourself that they have, by and large, adhered to the scientific method in their work.

 

Which option do you think makes the most sense?

 

You also have the idea of authority bass ackwards. We do not view the Theory of Evolution by Natural Selection as valid because of the authority of Charles Darwin, we view Charles Darwin as an authority because he produced a theory that was consistent with the evidence to a greater extent than other theories and which has been validated by countless further researches.

[Delbert]

But our separation from a Chimpanzee is later than that of a spider monkey. If we evolved from great apes, then we would expect to share more DNA with them than other types of primates.

We didn't evolve from Chimpanzees. We evolved from species type not now in existence. There may have been a common ancestor somewhere down the line, but not from today's apes.

 

And as for intermediate steps, the fossil record is full of them. And even in animals walking in today's world. Like the Coots swimming in my local river, they are more or less one stop from being flightless. All they appear to be able to do it scoot along the water by flapping their wings, but never take off. Being members of the Crane family they're clearly on the cusp of having lost the power of flight.

Edited August 6, 2014 by Delbert

[ajb]

We didn't evolve from Chimpanzees.

That is correct.

 

We evolved from species type not now in existence. There may have been a common ancestor somewhere down the line, but not from today's apes.

Again, this would also be my understanding. I am sure others know details here, but we share a relatively recent ancestor with chimpanzees. We and chimpanzees share an older common ancestor with spider monkeys (my example for some reason). This is reflected in the DNA profiles and sits well with evolution. Others who know more about this I am sure can say plenty more.

[Greg H.]

Again, this would also be my understanding. I am sure others know details here, but we share a relatively recent ancestor with chimpanzees. We and chimpanzees share an older common ancestor with spider monkeys (my example for some reason). This is reflected in the DNA profiles and sits well with evolution. Others who know more about this I am sure can say plenty more.

I'm no expert in the life sciences, but this sits well with my own understanding based on my readings on the topic.

[Delta1212]

That is correct.

 

 

Again, this would also be my understanding. I am sure others know details here, but we share a relatively recent ancestor with chimpanzees. We and chimpanzees share an older common ancestor with spider monkeys (my example for some reason). This is reflected in the DNA profiles and sits well with evolution. Others who know more about this I am sure can say plenty more.

And, in fact, we can trace the point of divergence not only in the fossil record but through DNA analysis as well.

 

Put simply, there are certain types of mutations that become fixed in a population at a steady rate. By comparing the differences at specific locations in genome of two species, we can trace how far back in time they diverged.

 

Obviously, it's more accurate the more related two species are (and therefore the more recently they diverged) as different species can have clocks that run at slightly different rates depending on things like generation length, but if you know how fast a particular species's clock runs and have fossil evidence to help calibrate, it's another method of timing when two species diverged, and when used it does agree well with both the fossil record and, otherwise, with what we'd expect based on our current understanding of evolution.

[ajb]

@Delta1212 Thank for the extra details.

 

Put even shorter, the fossil record and DNA analysis all support evolution.

 

The OP was asking specifically about natural selection, which if I recall correctly is now believed to be the main driving force of evolution. What what I have read, Darwin was not the first to suggest evolution, but rather it was natural selection that he was proposing as the main mechanism. It was the fact that natural selection seems rather random and "not in line with God's great plan" that coursed the initial fuss.

[Ophiolite]

Indeed. Evolution had been proposed, for example, by Erasmus Darwin, Charles's paternal grandfather. Comte de Buffon guardedly spoke of it in the late 18th century. Lamarck trumpeted it in the early 19th, but got the mechanism badly wrong. (That said Darwin dabbled on and off with forms of Lamarkism through the various editions of On the Origin of Species.)

[chadn737]

Whether or not Natural Selection is the driving force is still a matter of debate. Kimura argued that it was Genetic Drift, not Natural Selection that explained evolution at a molecular level.....its important to note that Kimura was talking about molecular evolution, not necessarily phenotypic evolution. Masatoshi Nei, whom I'm a fan of and increasingly agree with argues that Mutation is actually the primary force as it is the ultimate source of new variety, whether for Natural Selection or Genetic Drift. In reality, these are all probably equally valid, depending on the context. If you are looking to explain phenotypic evolution at a whole organismal level, then you might be most interested in Natural Selection. If you are looking to understand Genomic evolution at the molecular level, Genetic Drift might be the major player, and if you are looking to understand evolution from a very deep long term level, then Mutation, the ultimate source of novelty may be the most appropriate.

[Delta1212]

Whether or not Natural Selection is the driving force is still a matter of debate. Kimura argued that it was Genetic Drift, not Natural Selection that explained evolution at a molecular level.....its important to note that Kimura was talking about molecular evolution, not necessarily phenotypic evolution. Masatoshi Nei, whom I'm a fan of and increasingly agree with argues that Mutation is actually the primary force as it is the ultimate source of new variety, whether for Natural Selection or Genetic Drift. In reality, these are all probably equally valid, depending on the context. If you are looking to explain phenotypic evolution at a whole organismal level, then you might be most interested in Natural Selection. If you are looking to understand Genomic evolution at the molecular level, Genetic Drift might be the major player, and if you are looking to understand evolution from a very deep long term level, then Mutation, the ultimate source of novelty may be the most appropriate.

I think if you're going to talk about a "primary driver" you need to specify what is being driven. Mutation seems to be the primary driver of variation and natural selection the primary driver of adaptation. I'm not sure it is fair to call one or the other (or genetic drift, which is probably one of the larger drivers of speciation) the primary driver of "evolution."

 

As an explanation for the variety of life we see around us, why it is the way it is and how it got that way, mutation, natural selection and genetic drift are all necessary but not sufficient elements. It's a bit like asking whether the primary driver of a bike is the pedals, wheels or rider. You might be able to make a stronger case for one or another if you really wanted to, but remove any of those elements and your bike isn't going to get very far before it runs into problems.

[Delbert]

Indeed. Evolution had been proposed, for example, by Erasmus Darwin, Charles's paternal grandfather.

And probably in the mind of others before the above, like farmers and anyone involved growing and reproduction. But of course, and apparently not unlike Darwin who delayed publication, too afraid to voice their views for fear of the response. Indeed, go back far enough and one would doubtless be tied to a post and set alight.

 

And what's more, I have the doubters knocking on my door quite regular (perhaps they've got me identified as a target!), touting the idea nature is fixed (no evolution). Perhaps I encourage them by countering their argument.

 

On a slightly different tack, a radio program today mentioned how the bacteria that causes stomach ulcers was discovered. It made no mention of the individual that discovered it, who I understand was ostracised because he was going against well established procedure.

[harshgoel1975]

Adaption is the key characteristic ... , in every situation living and non living ( i know using non living will create a point of argument) adapt to new situation this how bacteria. virus , animal and human were able to survive....I fully agree with Delbert Point

[StringJunky]

harshgoel1975, on 10 Aug 2014 - 11:48 AM, said:

Adaption is the key characteristic ... , in every situation living and non living ( i know using non living will create a point of argument) adapt to new situation this how bacteria. virus , animal and human were able to survive....I fully agree with Delbert Point

But you need mutation first to make adaptation an available option. if the variety isn't there than adapting is not possible.

[Endy0816]

On a slightly different tack, a radio program today mentioned how the bacteria that causes stomach ulcers was discovered. It made no mention of the individual that discovered it, who I understand was ostracised because he was going against well established procedure.

 

Marshall and Warren.

 

http://www.csicop.org/si/show/bacteria_ulcers_and_ostracism_h._pylori_and_the_making_of_a_myth/

[Delbert]

But you need mutation first to make adaptation an available option. if the variety isn't there than adapting is not possible.

Of course.

 

And no mutation would simply mean we wouldn't be here. For the blindingly obvious reason we, along with all other live forms, would be unable to deal with a changing environment.

 

P.S. Been watching a nest of Coots on my local river. They hatched nine young. After about a couple of weeks they were all dead. They promptly started again, which resulted in six young. There are now two left. Now that's what I call the brutal tooth and claw of selection of the fittest.

[Ophiolite]

P.S. Been watching a nest of Coots on my local river. They hatched nine young. After about a couple of weeks they were all dead. They promptly started again, which resulted in six young. There are now two left. Now that's what I call the brutal tooth and claw of selection of the fittest.

And probably the application of blind chance too.

[Arete]

 

1.how large the sample of study darwin conducted was?

2.how many accurate prediction the theory has made?

3.what kind of sampling method darwin used? probability or non probability?

4. did darwin have any researcher bias i.e. his thought was effected by somebody's idea?

5. what is the effect size of the scientific field where darwin conducted research?

 

 

 

I'm afraid these questions demonstrate a distinct lack of understanding of the work Charles Darwin actually conducted on the theory of evolution via natural selection. Darwin was a gentleman scholar and a natural historian. He largely described the natural world as he observed it. A good example of the type of work he did is given in The Voyage of the Beagle. As a result, the inception of the theory of evolution via natural selection was not via an explicit experiment, but through observation of the natural world, making many of your questions invalid.

 

In answer:

1. Not applicable.

2. Since Origin was published evolutionary theory has accurately predicted the outcome of many thousands, if not millions of scientific studies.

3. Not applicable.

4. Darwin did not work in isolation. Here is a list of other scientists who influenced his work

5. Not applicable.

 

Ultimately, the specific details of the studies that led Darwin to conceiving the theory of evolution are rather moot, as the experimental effort in validating the theory since its inception has been immense. The sample size and statistical significance of this collective body of experimental evidence is overwhelming - you're talking many thousands of experiments, each with large numbers of replicates, and large effect sizes.

 

Some famous examples:

1. Endler's Guppy experiment

2. The Lederberg Experiment

3. The Lenski experiment

4. The Losos lab Anolis experiment

Edited August 11, 2014 by Arete

[Delbert]

And probably the application of blind chance too.

Chance is presumably identified in physics as a classified and measurable quantity.

[studiot]

 

Delbert

Chance is presumably identified in physics as a classified and measurable quantity.

 

In Mathematics yes definitely.

 

In Physics it is not so easy

[Delbert]

In Mathematics yes definitely.

I think you will find it is probability.

 

Whereas I understand chance is the occurrence of something for no identifiable reason, with probability being something happening with an identifiable reason.

[studiot]

 

Delbert

I think you will find it is probability.

 

Whereas I understand chance is the occurrence of something for no identifiable reason, with probability being something happening with an identifiable reason.

 

 

Not at all.

 

I find if you don't understand someone else's post the best thing to do is ask what they meant.

Edited August 11, 2014 by studiot

[Ophiolite]

I think you will find it is probability.

 

Whereas I understand chance is the occurrence of something for no identifiable reason, with probability being something happening with an identifiable reason.

That's not how I understand chance. A wide range of dinosaurs were well adapted for the environment of the late Cretaceous. Very few were well adapted for the environments associated with the chance Yucatan impact.

[Delbert]

Very few were well adapted for the environments associated with the chance Yucatan impact.

Since assigning the description of 'chance' to a consequence of celestial mechanics, I clearly don't understand the concept of chance. Moreover, from such it seems to me that chance would presumably account for just about anything. I wasn't expecting the close approach of the Moon the other day, so presumably that was a chance event.

 

The asteroid (or whatever) impact was a predictable event had the dinosaurs and a computer. It wasn't a chance event.

 

I would even go farther and suggest there is no such thing as a chance event. All events are a consequence of a process. There may be events whereby we may not understand the process (quantum mechanics might be one), but that doesn't make them a chance event.

[studiot]

 

I would even go farther and suggest there is no such thing as a chance event. All events are a consequence of a process. There may be events whereby we may not understand the process (quantum mechanics might be one), but that doesn't make them a chance event.

 

 

You misunderstand chance.

 

Consider chance as a process that cannot be predicted.

 

This is not the same as the opposite of predictability ie non predictability.

 

Ophiolite has offered an interesting idea, that many natural processes are actually a combination of a predictable element, possibly a non predictable element and also an element that cannot be predicted. +1

 

Suppose I tell you I am going to write down a number that will be either 1 or 0.

 

Can you predict what number I will write down?

 

Now suppose I also tell you that I will calculate the result of dividing 4 by 4 and write down the result.

 

You should now be able to predict which number I write down. (No chance pure predictability.)

 

Now suppose instead I decide to flip a fair coin and write down 1 for heads and 0 for tails.

 

Can you now predict what I will write down or is chance now involved?

 

Suppose I now decide to flip the coin to decide whether I will flip the coin a second time or calculate 4 divided by four.

 

Is this not now a mixture of chance and predictability?

 

Life is manifold more complicated than these simple examples.

 

Suppose I take a 100kg sample of sand from the beach and mix it up well and divide it into ten 10kg samples.

 

Suppose I now perform a sieve analysis on each sample.

 

Will any of my two samples exactly match?

 

Can you predict the grain size distribution in advance?