Fossil and Evolution

[Dancing David]

Oh. About the Burgess shale. I was being provocative by calling it a cover up. But let's look at what happened.

Walcott of the Smithsonian discovered these fossils in 1909. They were very mysterious and they did nothing to promote the theory of evolution, so they sat in the drawers at the Smithsonian, where Walcott had put them (hid them?) for about 50 years.

They caused quite a stir when Whittington and others brought them out for all to see in the 1960s. It prompted the label "evolution's big bang" and "Cambrian explosion".

I think it is difficult to understand why Walcott's discovery was not generally known, that's an understatement, for 50 years. Walcott was no amateur and was in fact, with one of the biggest museums in the world.

You think I make this up that it was intentionally hidden, so why don't you come up with a plausible explanation why such interesting evidence would not be shared with the world.

This is irrelevant to the topic at hand.

There are many reasons that do not involve a coverup:

-They are not large fossil remains of the dinosaurs, and there was this huge competition to find them.

 

[Dancing David]

This is an excellent discussion of the probability arguments. I take a more simple minded approach. We're here. We can see that genetic mechanisms got us here. There is no evidence of irreducible complexity.

So figuring out how that occurred in 3.5 billion or so years would not involve calculating if random chance had enough time to work. If there were a problem with timing, I'd be looking to fine tune evolution theory, not claiming it was evidence of a designer.

While I understand the principle of not looking for preconceived evidence, there is another one called forming the most logical hypothesis. We are here so obviously we got here. There is no evidence for gods having anything to do with it so a designer is not a supportable hypothesis.

In addition, it's about as complex as tracking the weather to figure this mutation timetable out. While most evolution deniers think one can come up with a single rate, that isn't how selection pressures work. And we have seen experimental analyses of viruses which indicate some areas on DNA and RNA strands are more stable and some mutate more readily (also a selection advantage in a changing environment for a microbe to have more mutations affecting its outer protein coat while conserving the inner vital functions with less mutations). Then you must throw in the variety of ways we see genetic material exchanged both inter and intra species. It ain't all by sex.

I see no reason to even investigate the timetable problem if the goal is to use it to support or refute evolution. It can do neither nor is any more evidence required which supports evolution theory. We do use the rate of mutation to track organisms back to when the last related ancestors likely occurred. And the number of mutations by which two organisms differ can tell you if two infections are epidemiologically linked.

That guy who thought he was so clever claiming there couldn't have been enough time for evolution to explain the variety of species on the planet was naive.

Here...

 

[Dancing David]

No, you don't understand.

You continue to adopt the "design mindset." Consequently, your analogy above is false, because you presume, a priori, that there is a subset of some total possibilities from which an organism will eventually arise to finally discuss the issue in this forum.

The above premise is simply false. We cannot work backward from our present state and estimate the odds of our being here, any more than we can estimate the odds of a ball falling into the slot of a roulette wheel containing no slots.

Prior to the universe existing, the odds of any particular future event occurring are equal, because given a set of limitless possibilities, all outcomes are equally likely.

To correct your analogy, you would have to take an infinite set of possible letters of infinite combination and then estimate the odds of an infinite number of possible stories of infinite length written in an infinite number of possible languages.

What are the odds of everything happening by chance, when selected from a set containing all possibilities?

Unity.

We are here, because it is inevitable, and it is not philosophy to say so. What IS philosophy is to say that "we" must be of some particular composition/nature, because we could have been anything, in any shape, size or composition.

If we had appeared in some other universe, made of gold instead of carbon, and the entire universe was constituted in a manner which permitted this, then that's what we would be.

Design is only meaningful in view of actual knowledge of the designer -- otherwise, given that infinite set of possibilities, even the designer's proverbial Boeing 747 could have occurred by pure accident in a universe which looked exactly like a junkyard.

Such a thought is only absurd, because we are here thinking such a thing from our perspective, But, in the universe where the 747 sits alone in the blackness of space, it's completely rational -- and in fact, it's the only possible outcome.

You have limited yourself to a mindset which prevents you from accepting that random chance can explain everything. Everything, that is, except for God, because God is the literal antithesis of randomness. If God exists, then randomness cannot, because God must know all in order to be God -- and randomness eschews all possible advance knowledge.

To bring this back to your English story analogy, could one million monkeys with typewriters bang out the complete works of Shakespeare, given sufficient time?

The answer is unequivocally, Yes. In our universe, this incredible accident actually occurred -- accomplished not by one million monkeys, but by only ONE!

His name, of course, was William Shakespeare.

N.B. And, he did it with a quill pen!

Here...

 

[Dancing David]

And the monkey and 747 analogy only applies to the random part--but evolution is far from random...it has input which makes some features "stick" and others not (natural selection)--that is like monkeys typing and every time one of the letters in the next shakespearean word sticks when they type it and the rest just fall off the page because they have nothing to make them stick. Or a worldwind assembling things again and again and the good designs sticking...I mean airplanes evolved from earlier airplanes...and then from humans looking at birds...and it evolved in nature numerous times because sometimes, gliding or flying or being able to be airborne enhances an organisms chance for survival or reproduction. Heck, even the clueless dandilion fluff seedlings have evolved that trick! Creationists never really seem to "get" the natural selection part of the equation, because they are too fixated on the appearance of design. Plus, we only see the experiments that had some degree of success and not the eons of failures nor all trillions upon trillions of gametes that never fertilize anything...all the cells that never devided...we see only what's left...what worked...and we've just developed the tools to see these things and understand what we are looking at and how it fits together.

Dawkins mentioned that--the thing how creationists speak of it all coming about by "chance"--they over emphasize the randomness (like point mutations) and don't seem to grasp the invisible tiny ratcheting through the eons that IS the selction process. There's tons of "mutations" going on--lots of molecules with life-ish properties--but only the workable ones stick around. And the "next step" only has to happen once. ONCE...in eons...One sticking factor that allows for another sticking factor...non disjunction for example. A translocation that only works when mated with a relative that carries the same mutation. If it's a good mutation--it can evolve to a whole new species. That's one of the things that happened between us and our common chimp ancestor. Cool, eh?

Here ...

 

[Dancing David]

That is a basically deterministic argument, you have chosen the end point of the process of natural selection and so that is using the deterministic mind set. Also you have set the parameters in an interesting fashion in presupposing that DNA is needed for life to occur.

As for the "RNA leading to DNA has been debunked" just stating that does not make it true, there was much discussion on a prior thread about the theory on abiogenesis. I believe that you can state it has been debunked, I am not sure it has been.

So lets us start with something a little more like the theory of natural selection as opposed to your 10^70 machines (monkeys) typing to make Shakespeare.

Let us say we have a set of molecules in a puddle and for the sake of simplicity we say that there are a hundred members of ten different molecules. What is the chance that over a given period of time they will create an amino acid? That has pretty much been shown to have the potential to occur in a very short period of time.

So it is possible within a short period of time to reach complex molecules like amino acids.

Then we take a different set, say two amino acids in another puddle and for some unfortunate reason there are only two of these molecules but we can hypothesize that there are chemical precursors of the aminos in the puddle and that they will regenerate if degraded over time.

What then is the chance that a post amino complex (PAC) will arise that is a combination of the two that does not degrade as rapidly?

If we say that the aminos will bump into each other every day in this puddle and that there is a one in a thousand chance they could potentially make a PAC then after ten years it is likely that a PAC will have occurred 3.65 times in that puddle.

We can then alter the puddle and say that there are a hundred of each of the aminos that exist before they degrade but that then means there is 10,000 times higher chance of a PAC arising because the aminos still bump all the other aminos once a day. That means that over a ten year period there will be 36,500 occurrences of the PAC over ten years. And even if the chance of making a PAC is one in a million there will be the occurrence of the PAC 36.5 times in the puddle.

Now what then is there the chance that a PAC be created in a form that helps to catalyze the formation of one of the amino acids? Lets us say that with daily bumping again, and the one in a thousand chance of creating a PAC that there is a one in a thousand chance of a ScPAC arising. That then depends on the degradation of the PAC and the time span for it to co-exist with another PAC in the puddle and then the chance that they will create a SPAC so let us set them each at one in a thousand: PAC and PAC, PAC bumping (just to make it easier) and PAC creating ScPAC. That means that there would be a one in a billion chance of a ScPAC being created in the puddle on a daily basis. And if that seems to be too high an odds than we could potentially raise the number of aminos is the imaginary puddle.

So then over a billion years with the one in a billion chance we would have the 365 occurrences of the creation of a ScPAC.

So again I would argue that it is the numbers game again but slanted in my favor. I still hold that abiogenesis is a theory and that it should never be a dogma.

I agree that there should always be room for doubt but I can begin to stack the numbers to have an abiogenetic event. I can increase the numbers of aminos, I can increase the number of interactions and so I could potentially have a sequence that goes like this aminos>PACs>ScPAC>aggregates of self catalyzing PACs> AgScPACs>lipids created by AgScPACs>lipids enveloping LcAgScPACs>LeLcAgScPACs>protocell

So just sheer numbers could potentially lead to abiogenesis. Again millions of molecules interacting over billions of years seems to be a likely possibility that it will lead to abiogenesis.

Now I agree that the odds of the DNA/RNA complex arising are extremely low but once we get to proto cells the mathematics begin to stack in the favor of self organizing systems and those that through constrained change and natural selection will become self organizing. Because the sheer power of huge numbers of molecules and huge amounts of time we now can add the power of CC/NS to say that the odds get processionaly smaller of leading to a self organizing event.

So yes if we ask what are the chances that 10^70 monkeys typing randomly over 15 billion years will produce a 1000 letter sequence of Shakespeare then the odds are very low. But if we ask if 10^70 monkeys are playing with Lego’s and the chances arise that the Lego’s will start to self organize then I think I can slant the odds in the favor of self organization in slightly less than a billion years.


Now I am not saying that abiogenesis should be dogma, I am after all the one who says things like:

So I completely agree that abiogenesis and CC/NS are theories the question is what is the data and what theory matches the data best?

And I agree if we ask what are the odds that 10^70 critters acting over 15*10^12 years will create a DNA/RNA complex specifically is a very low probability, but if we ask what are the odds that something like a self organizing set like DNA/RNA will arise in that time period the odds are significantly higher.

here, although that last part should be 15*10^9 years.

 

[Dancing David]

This is an example of the typically dishonest casting of evolution as completely random. No need to even bother checking the math - natural selection has been completely ignored.

Here...

 

[sinclairmcevoy]

You just did in my opinion. Others will pick you apart from lack of manners or self esteem. Innocent until proven guilty.....

 

[Dr Adequate]

We can watch the creation of life from non-living material happen in the lab?

Yes, isn't that fun?

 

[Dr Adequate]

You think I make this up that it was intentionally hidden, so why don't you come up with a plausible explanation why such interesting evidence would not be shared with the world.

Because the fossils in question were, as you pointed out, sitting in the drawer of the Smithsonian. No-one examined them in enough detail to see how interesting they were. As soon as their interesting nature was discovered, scientists ran about excitedly telling everyone who'd listen.

If you think there was a cover-up by those evil evolutionists, why do you suppose it was evolutionists who turned the Burgess Shale into a cause celebre. I didn't notice the creationists doing any of the scientific work or producing any of the scientific publications. 'Cos of course, that's not what creationists do.

 

[Skeptic Ginger]

Sorry, but I have to strongly disagree with your timeline here.

It is true that we are constantly accumulating new evidence, and new kinds of evidence. It is true that evolution has been confirmed beyond a reasonable doubt for some time.

But you're flat-out wrong to suggest that there were perceived problems with evolution some 30-40 years ago. The last serious scientific debate that I am aware of about the truth of evolution is nearly a century old. The arguments that you're referring to about evolution deniers is not based on any challenge to the theory of evolution, it is based on cherry-picked quotes from a debate about how it occurs. (Specifically punctuated equilibrium vs gradulism.) And the case for evolution was very strong long before the latest and greatest lines of evidence were introduced through molecular genetics.

The fact that you believe there was a serious debate some 40 years ago means that you've accepted Creationist lies and misrepresentations about the state of science at that time. You have obviously not accepted their overall message, but they've mislead you.

Regards,
Ben

The case for evolution has been strong since Darwin's thesis. But the arguments about micro and not macro evolution were not confirmed to a scientific standard until genetic science became more prolific. You seem to be drawing the line of scientific certainty a little further back than I do. I agree but don't think a science purist would.

 

[Ben Tilly]

The case for evolution has been strong since Darwin's thesis. But the arguments about micro and not macro evolution were not confirmed to a scientific standard until genetic science became more prolific. You seem to be drawing the line of scientific certainty a little further back than I do. I agree but don't think a science purist would.

Where do I start?

• The case for Darwin's theory of evolution has not been strong since Darwin's thesis. To the contrary it faced a number of major problems. One was the fact that number of lines of evidence from physicists suggested that the Earth could be no more than 100 million years old - not enough time for evolution to happen. And another was that various breeding experiments strongly suggested that animals have "natural types" which they tend to revert to. The net effect was that considerable scientific debate remained about the validity of Darwin's theories some 50 years after Darwin wrote The Origin of the Species. One by one these problems were eliminated (radioactivity resolved the age of the earth problems, population genetics advanced to the point that it could explain the apparent evidence for "natural types") and Darwin's theory won. But it severely misrepresents the history of science to think that it wasn't an uphill battle for a long time.
• I'd like you to come up with sources for your belief that there were serious unresolved problem about the possibility of micro versus macro evolution. There were serious issues around rates of change - see the punctuated equilibrium debate - but we've had solid proof that micro changes can add up to a species change for a very long time. (See, for instance, the phenomena of ring species.) And we've had no reason to doubt that since the modern synthesis became accepted in the 30s and the 40s. (Actually all of the pieces of the synthesis predate that, but that's when people put the pieces together and gave it a name.) I should note that the modern synthesis included a solid understanding of genes and inheritance. (Though they didn't understand how it was encoded in DNA. And there were a lot of subtleties, like jumping genes, that they couldn't fit into their pictures.)
• Please define what you mean by "a scientific standard". Because by the standards actually used by working scientists of the day, it was solidly accepted.
• You keep on making reference to "science purists". Please define the term. And explain it in sufficient detail for me to understand why I am not a science purist by your definition.

Regards,
Ben

 

[RecoveringYuppy]

Are there any records of how the consensus developed in favor of Darwin's theory?

And might you two be talking at cross purposes? While Darwin's contribution to the theory may have not been accepted immediately, I'm under the impression that the fact of common descent had been accepted amongst biologists for three or four generations prior to Charles Darwin.

And while physicists were coming up with 100 million years for the age of the Earth until the late 1800's, didn't the geologists accept a longer time based on geologic evidence from about 1830?

 

[Ichneumonwasp]

Ben-

Thank you for your clearly written explanation. I think that it, along with Dr. Adquate's information about the forams, clears up a lot of questions I had about evolutionary time frame. I will give a more complete explanation of my reasoning later. Suffice it to say, I retract the questions (in so far as I asked any) in my OP.

That is not say that I do not still have problems with the way in which my question was dealt from both a pedagogical/androgogical and a general human courtesy standpoint, about both of which I will also post later.

Nonetheless, I reiterate the apologies that I have already offered about my ill-conceived and ill-posed OP and retract what I said in it.

Sincerely,

Michael

I'm sorry that I passed over this post earlier. If no one else has done so from your previous or this post, let me be the first to say Bravo. It takes a lot of guts to do this. I respect that.

 

[Ben Tilly]

Are there any records of how the consensus developed in favor of Darwin's theory?

There are copious records. But I don't have a single good reference to quote. My own understanding of the topic is based on having audited a graduate level course on evolution theory back in the early 90s, having read a lot of popular works (including virtually everything by Gould), and having engaged in too many online discussions.

However http://en.wikipedia.org/wiki/Modern_evolutionary_synthesis gives you a pretty good overview of what was involved in the final acceptance of Darwin's theories.

And might you two be talking at cross purposes? While Darwin's contribution to the theory may have not been accepted immediately, I'm under the impression that the fact of common descent had been accepted amongst biologists for three or four generations prior to Charles Darwin.

This is sort of true. There were a lot of biologists who believed in common descent, and a number of theories of evolution out there. (That's why I've been careful to keep on saying Darwin's theory of evolution rather than just the theory of evolution.) However common descent was far from universally accepted among biologists. And even less than that was the acceptance of Darwin's theory of evolution.

And while physicists were coming up with 100 million years for the age of the Earth until the late 1800's, didn't the geologists accept a longer time based on geologic evidence from about 1830?

Yes. Lyell estimated a minimum of 240 million years. Darwin himself estimated that a particular valley (the Weald of Kent) could not have taken less than 300 million years to create. (I should note, estimated very incorrectly - this estimate was taken out of later editions of The Origin of the Species.) But Kelvin proved that while the Sun might reasonably be as much as 20 million years old, it would be hard to credit that it could be 100 million years old.

But it wasn't as simple as just "geologists versus physicists". For instance John Phillips, the geologist who disproved Darwin's estimate of the age of that valley, came up with his own estimate for the age of the Earth. His estimate was about 100 million years old. (It should be noted that Phillips accepted evolution, but not Darwin's theory.)

In any case my point remains - there was considerable scientific reason to disbelieve Darwin's theory of evolution for some time after he published his theories.

 

[JoeTheJuggler]

And might you two be talking at cross purposes?

Something like that seems to be happening.

There's a vast difference between saying the theory has been strong since Darwin and talking about when it came to be the accepted paradigm (as they say). The consensus of the scientific community is one thing, and the actual merits of the idea itself is something else.

I hate to be all sun-shiney, but I think you're both right!

 

[articulett]

There are copious records. But I don't have a single good reference to quote. My own understanding of the topic is based on having audited a graduate level course on evolution theory back in the early 90s, having read a lot of popular works (including virtually everything by Gould), and having engaged in too many online discussions.

However http://en.wikipedia.org/wiki/Modern_evolutionary_synthesis gives you a pretty good overview of what was involved in the final acceptance of Darwin's theories.



This is sort of true. There were a lot of biologists who believed in common descent, and a number of theories of evolution out there. (That's why I've been careful to keep on saying Darwin's theory of evolution rather than just the theory of evolution.) However common descent was far from universally accepted among biologists. And even less than that was the acceptance of Darwin's theory of evolution.



Yes. Lyell estimated a minimum of 240 million years. Darwin himself estimated that a particular valley (the Weald of Kent) could not have taken less than 300 million years to create. (I should note, estimated very incorrectly - this estimate was taken out of later editions of The Origin of the Species.) But Kelvin proved that while the Sun might reasonably be as much as 20 million years old, it would be hard to credit that it could be 100 million years old.

But it wasn't as simple as just "geologists versus physicists". For instance John Phillips, the geologist who disproved Darwin's estimate of the age of that valley, came up with his own estimate for the age of the Earth. His estimate was about 100 million years old. (It should be noted that Phillips accepted evolution, but not Darwin's theory.)

In any case my point remains - there was considerable scientific reason to disbelieve Darwin's theory of evolution for some time after he published his theories.

Yes, but since the discovery of DNA, I don't think there is any reputable scientist who would take issue with it. I mean the DNA is just so fantastically illustrative of what Darwin could only imagine. But creationists still see the "intelligent designer" as some sort of tinkerer...or at least the guy who started it all--and some people accept evolution, but think god adds something special, like "souls". However only half of the American public accepts evolution, and this is because they believe there is a controversy in the scientific community; I would be hard pressed to pick a date as to when the controversy faded from the scientific community, because there are still some semi-scientists who try to obfuscate. Though, with the advent of DNA, it just makes them look like brainwashed religious old men. Intelligent Design proponents reluctantly acknowledge the undeniable aspects of evolution and then they try to insert a designer into the fuzzier areas as they deny that science has explained anything they attribute to their invisible designer.

 

[Ben Tilly]

Yes, but since the discovery of DNA, I don't think there is any reputable scientist who would take issue with it. I mean the DNA is just so fantastically illustrative of what Darwin could only imagine. But creationists still see the "intelligent designer" as some sort of tinkerer...or at least the guy who started it all--and some people accept evolution, but think god adds something special, like "souls". However only half of the American public accepts evolution, and this is because they believe there is a controversy in the scientific community; I would be hard pressed to pick a date as to when the controversy faded from the scientific community, because there are still some semi-scientists who try to obfuscate. Though, with the advent of DNA, it just makes them look like brainwashed religious old men. Intelligent Design proponents reluctantly acknowledge the undeniable aspects of evolution and then they try to insert a designer into the fuzzier areas as they deny that science has explained anything they attribute to their invisible designer.

I'd disagree on the "reputable scientist" line. There are plenty of reputable scientists who believe in Creationism. In fact I think that I've heard that Gould had a PhD student who was a Creationist. I certainly knew a grad student in molecular and cell biology who was a Creationist. I have every reason to believe that she would get her PhD. And the father of a good friend was a chemist and a Creationist. (Said friend finished his PhD in math. However I do not count math as a science.)

"No scientific controversy" is not the same as "all scientists agree". Nor does knowledge of one area of science translate into knowledge of another.

Also it is my understanding that about 9% of the American public fully accepts evolution. About half believe that the Bible is inerrant. And the rest have beliefs somewhere in between. So your estimate that half of the American public believes in evolution is somewhat optimistic.

About picking a solid date, that is always hard. In the end paradigm shifts finish when all of the adherents of the previous paradigm die. To name a notable recent example, Fred Hoyle had not accepted the Big Bang right until his death in 2001. Yet the history of science will remember the discovery of cosmic microwave background radiation in 1964 as the defining fact that confirmed the Big Bang theory. For nearly 40 years Hoyle regularly published papers on this topic that were more and more irrelevant to mainstream astronomy.

Cheers,
Ben

 

[Skeptic Ginger]

Where do I start?

• The case for Darwin's theory of evolution has not been strong since Darwin's thesis. To the contrary it faced a number of major problems. One was the fact that number of lines of evidence from physicists suggested that the Earth could be no more than 100 million years old - not enough time for evolution to happen. And another was that various breeding experiments strongly suggested that animals have "natural types" which they tend to revert to. The net effect was that considerable scientific debate remained about the validity of Darwin's theories some 50 years after Darwin wrote The Origin of the Species. One by one these problems were eliminated (radioactivity resolved the age of the earth problems, population genetics advanced to the point that it could explain the apparent evidence for "natural types") and Darwin's theory won. But it severely misrepresents the history of science to think that it wasn't an uphill battle for a long time.
• I'd like you to come up with sources for your belief that there were serious unresolved problem about the possibility of micro versus macro evolution. There were serious issues around rates of change - see the punctuated equilibrium debate - but we've had solid proof that micro changes can add up to a species change for a very long time. (See, for instance, the phenomena of ring species.) And we've had no reason to doubt that since the modern synthesis became accepted in the 30s and the 40s. (Actually all of the pieces of the synthesis predate that, but that's when people put the pieces together and gave it a name.) I should note that the modern synthesis included a solid understanding of genes and inheritance. (Though they didn't understand how it was encoded in DNA. And there were a lot of subtleties, like jumping genes, that they couldn't fit into their pictures.)
• Please define what you mean by "a scientific standard". Because by the standards actually used by working scientists of the day, it was solidly accepted.
• You keep on making reference to "science purists". Please define the term. And explain it in sufficient detail for me to understand why I am not a science purist by your definition.

Regards,
Ben

Well to oversimplify things, because I'm not interested in a dissertation here, we started with Darwin's observations. It is my belief if you just observed life as one could have 175 years ago, especially considering by that time humans had bred domestic animals and food crops, there was clear evidence of evolution. But people at that time still had mythical ideas to overcome. Since I don't buy the myths and neither did all people then, from the point of scientific evidence the only competing theory was gods had a hand in it. So you could go with evolution as the most plausible theory even as far back as when Darwin proposed it. While there were problems with explaining everything, what do you consider competing theories of the day? And why would 100 million year old Earth even be considered a problem for evolution theory to overcome at that time since no one would have been calculating the rate of DNA mutations.

Next we added in a large amount of data from the fossil record. More weight toward the evolution theory. But one could argue that evidence was lacking as to what created new species. In my hypothetical travel back in time, I was already convinced there were no competing theories. But a lot of scientists would have been saying there was a suggestion one species evolved into another, but there wasn't enough evidence to say speciation occurred without a doubt.

So my science purist would be a scientist who would say your theory looks good, but until you have very specific evidence supporting speciation it remains speculative. I would still be saying there were no competing theories.

1930s and 1940s

New thinking on species developed in the 1930s and 1940s. Geneticist Theodosius Dobzhansky2 and systematist Ernst Mayr3 developed the idea that:

* Species are reproductive communities, with their members capable of interbreeding among themselves, and not, as the general rule, with members of other species.
* Evolution of new species centers on how changes occur in adaptations so that an ancestral species is split into two (occasionally more) descendant species, with interbreeding no longer possible between the members of what have evolved into descendant, or "daughter," species.

This timeline of evolutionary thought shows the understanding of speciation to have advanced in the 60s-70s.

According to this, in 1966, the genetic code was "cracked" when, "Marshall Nirenberg, Heinrich Mathaei, and Severo Ochoa demonstrated that a sequence of three nucleotide bases (a codon) determines each of 20 amino acids. And this site notes that 1977 was the dawn of "Biotech" which I would define as the beginning of today's genetic science field.

Even though microbes were first seen in the 1600s, I don't know that anyone in Darwin's time would have considered microbes preceding and evolving into insects, plants and animals. It wasn't until genetic mechanisms were understood that evolution theory was a complete theory. And regarding Mendel's work and other demonstrations of genetic mechanisms at work, knowing something occurs is not a complete theory until you know how it occurs.

What do you consider was the defining evidence between Darwin's work and when you consider the theory was supported by overwhelming evidence and what competing theories were there before it was clear one was correct? I consider the breakthroughs in genetic science which revealed the mechanisms of evolution to be the overwhelming evidence. I was convinced before that. A person who interpreted science in a more 'pure' form would have insisted on the genetic evidence explaining how evolution occurred not just that it was observed occurring and there were no competing theories.

 

[Skeptic Ginger]

Are there any records of how the consensus developed in favor of Darwin's theory?

And might you two be talking at cross purposes? While Darwin's contribution to the theory may have not been accepted immediately, I'm under the impression that the fact of common descent had been accepted amongst biologists for three or four generations prior to Charles Darwin.

And while physicists were coming up with 100 million years for the age of the Earth until the late 1800's, didn't the geologists accept a longer time based on geologic evidence from about 1830?

It's interesting you should bring this up. I work across fields of medicine and law and have interests in multiple fields of science. Crossing territories you see very quickly how people have their own tunnel to peer at the world through, even if one is a good skeptic.

The emphasis Ben put on the geological evidence differs from the weight I put on the genetic evidence. It's interesting indeed.

 

[Skeptic Ginger]

...
In any case my point remains - there was considerable scientific reason to disbelieve Darwin's theory of evolution for some time after he published his theories.

Name one besides god beliefs. And the time line you think left doubt about Darwin's theory, is that the argument people gave at that time? It seems hard to believe they would have had anyway of knowing how fast evolution occurred when the theory was first proposed. I have never read Darwin's work. Does he suggest a timeframe for his theory?

Also, I see nothing in the Wiki article that says: This was the clincher and here's the date. Nor do I see much in there which contradicts my post. Unless you consider the day genetic mechanisms were first identified as all that was needed. I would propose it took a lot closer examination of the new discovery to have a full understanding of it.