Piltdown and the search for Human Ancestors

[Baggins]

I was not aware that the Smithsonian Insitute endored creationist websites. You really ought to take a better look at this and stop this silly rant that is based on nothing but suppostion.

Hello Mr pot!

Are you saying that the web site you linked to isn't a right wing political web site?

It certainly isn't a mainstream science site.

 

[mark kennedy]

Hello Mr pot!

Are you saying that the web site you linked to isn't a right wing political web site?

It certainly isn't a mainstream science site.

The Discovery Institute is an Intelligent Design website and most of the fellows are actual scientists, philosophers and mathematitions. I think you are assuming that anyone who disagrees with your point of view must be a right wing wacko.

Why don't you just go look at the site and quit writing baseless ramblings.

 

[Baggins]

"The “Cambrian explosion” refers to the geologically sudden appearance of many new animal body plans about 530 million years ago. At this time, at least nineteen, and perhaps as many as thirty-five phyla of forty total (Meyer et al. 2003), made their first appearance on earth within a narrow five- to ten-million-year window of geologic time (Bowring et al. 1993, 1998a:1, 1998b:40; Kerr 1993; Monastersky 1993; Aris-Brosou & Yang 2003). Many new subphyla, between 32 and 48 of 56 total (Meyer et al. 2003), and classes of animals also arose at this time with representatives of these new higher taxa manifesting significant morphological innovations. The Cambrian explosion thus marked a major episode of morphogenesis in which many new and disparate organismal forms arose in a geologically brief period of time"

Try actually reading the article next time.

I did, I can't think why you would think I didn't, although it is tough going reading so much wooly thinking and disingenuous hand waving.
There is nothing in it that is proof that
million years isn't long enough to produce the cambrian fauna from the sort of bilateral animals that are found in the PreCambrian.

Ys it was a burst or morphogenesis, yes, Yes 70ma is a brief amount of geological time, but why is it to short to evolve arthropods from base bilaterata?

The precambrian period was billions of years where the most advanced life forms were bacteria and fauna for billions of years. Then in a very brief window of natural history most of the primary taxanomic catagories appear suddenly, fully formed, in six to ten million years.

This is simply not true, There is a
-70 ma window of opertunity to evolve from bilaterates to the Cambrian fauna. The Burgess shale has proved that the Cambrian explosion is mainly to do with preservation rather than sudden appearence., although this is still an area of research and contention in the palaeontological community.

The point was clear enough, you are comparing something with hundreds of nucleotides to cells that have millions. How you and everyone else is missing this is a mystery to me.

Why you would compare sponges to arthropods is a mystery to me, sponges are not ancestral to arthropods. They are just a simple animal, They were simple in the precambrian, they are simple today.

So What?

There is no known mechanism for writting such a specific line of DNA code. It does not happen in nature and it did not happen in real history. Bacteria does not become Eukaryote cells, it simply is a matter of suppostion not science.

For which you obviously have no proof beyond your own desire for it to be true.

Specific lines of DNA code are not written to solve certain problems. Changes in DNA happen through mutation and natural selection.

No one said bacteria became Eukaryotic cells, just thatthey have a common ancestor.

Worthless is how I would describe the Single Common Ancestor Model. It has had no basis for it's universal application and yet it is an a priori fact in the minds of most scientists. In fact, worthless is an understatement.

That is because for religious reasons you can't entertain it. Science calls common ancestry a well support theory.

This is because scientist don't entertain religious reasons to omit evidence like you do.

Baloney, you didn't read the article did you? You don't realize that this was published by a reputable scientific organization and go off into this mindless rant:

It doesn't appear to be a reputable scientific organisation to me, it appears to be a rightwing organisation with a political agenda.

I can tell that because I did read the article and then I scooted off around the rest of their site.

care to expand on what they are and what they are about?

They seem to be pretty cagey about it on their website.

Sure improved body plans would help but first they have to result from an adaptation. This kind of adaptive radiation only happens in the myths written by Darwinians.

Or alternatively after every major extinction in the whole geological record.

You say adaptive radiation is a myth, the scientific community says it has huge anounts of fossil evidence proving adaptive radiation, inluding that of the birds an mammals after the KT extinction.

Oh, who to believe, Mark or the whole scientific community, that's a toughie.

It gives many reason supported by modern scientific literature that is cited, quoted and not some crackpot organizations either. Read the paper next time before you start jumping to ill-founded conclusions.

All it's examples are comparing modern evolutionary examples, because they can do nothing else. But nowhere to they adress important points like the evolution of HOX genes and the evolution of regulatory genetics.

Those along with adaptive radiation are more than enough to explain the change from simple bilaterates to the Cambrian fauna in 70 ma.

You have no proof otherwise, and if that paper was your best shot then you failed.

It doesn't matter whether you believe in long fuse Cambrian explosion or short fuse, the palaeontological evidence shows it happened, and the palaeontological evidence will increase of the coming years and bring new supporting evidence as people start to look at the large late Pre-Cambrian deposits of Siberia and China.

But sadly your views will never change becaus ethey are based on your religious dogma not on any scientific basis.

 

[Baggins]

The Discovery Institute is an Intelligent Design website and most of the fellows are actual scientists, philosophers and mathematitions. I think you are assuming that anyone who disagrees with your point of view must be a right wing wacko.

Why don't you just go look at the site and quit writing baseless ramblings.

Meyer's conclusion:

An experience-based analysis of the causal powers of various explanatory hypotheses suggests purposive or intelligent design as a causally adequate--and perhaps the most causally adequate--explanation for the origin of the complex specified information required to build the Cambrian animals and the novel forms they represent. For this reason, recent scientific interest in the design hypothesis is unlikely to abate as biologists continue to wrestle with the problem of the origination of biological form and the higher taxa.


I don't know therefore goddidit

What a great scientist.

 

[Baggins]

Discovery's Center for Science and Culture has more than 40 Fellows, including biologists, biochemists, chemists, physicists, philosophers and historians of science, and public policy and legal experts,

But sadly no geologists or palaeontologists

 

[Baggins]

The Discovery Institute is an Intelligent Design website and most of the fellows are actual scientists, philosophers and mathematitions. I think you are assuming that anyone who disagrees with your point of view must be a right wing wacko.

Why don't you just go look at the site and quit writing baseless ramblings.

So it is just a whacko creationist site then.

It seems to have a nimber of links to articles of a "conservative" nature as well.

 

[Baggins]

"The Future of Conservatism: Back to Basics"
Featuring Heritage Foundation President Edwin J. Feulner, Ph.D.

Please join Discovery Institute in welcoming Heritage Foundation President Edwin J. Feulner to Seattle. Dr. Feulner is one of the founding fathers of modern American conservatism, as well as president of America's largest public policy think tank. The Heritage Foundation came to national prominence after the 1980 election, when it helped staff many positions in the Reagan administration

Seems like a nice balanced chap

 

[Baggins]

So would you say that with you and Meyer it basically comes down to an argument from incredulity that is premised by your belief in special creation?

I know that is what your standpoint is, but I'd be interested to know if it is meyer's as well.

Would you further agree that it is useless looking at studies in modern genetics and applying them to animals that are extinct and in a radically different environment?

 

[Split Rock]

The precambrian period was billions of years where the most advanced life forms were bacteria and fauna for billions of years. Then in a very brief window of natural history most of the primary taxanomic catagories appear suddenly, fully formed, in six to ten million years.

Not so. The Edicarian organisms of the Precambrian are an example of multicellular life preceeding the Cambrian.
http://www.peripatus.gen.nz/paleontology/Ediacara.html

Worthless is how I would describe the Single Common Ancestor Model. It has had no basis for it's universal application and yet it is an a priori fact in the minds of most scientists. In fact, worthless is an understatement.

Why is it worthless? Because you don't like it?

Provide us with some physical evidence that "Intelligent Design." providing a better explanation. So far neither you nor anyone at the Discovery Institute has managed to do so.

 

[Baggins]

I've just reread that "paper" again and there isn't a single mention of primative Protostomes like flat worms. That would be the obvious thing to compare arthropods to as something similar was ancestral.

Did I miss something in all that verbiage?

Wouldn't it have been useful to do some original research on the differences between athropods and flatworms rather than just trawl the literature and pull out some meaningless guff about how different arthropods and sponges are? I mean, it could possibly have supported their case nearly as well.

I know creationists have an aversion to original research but it might have given us something to actually talk about rather than that pile of twaddle.

And as I said before no mention of the evolution of hox genes, and all we got from Mark about adaptive radiation was some hand waving about how it has never happened, which flies in the face of the fossil evidence that it happens after every large extinction.

Same old same old.

 

[mark kennedy]

I did, I can't think why you would think I didn't, although it is tough going reading so much wooly thinking and disingenuous hand waving.
There is nothing in it that is proof that
million years isn't long enough to produce the cambrian fauna from the sort of bilateral animals that are found in the PreCambrian.

It seems so brief because the years before it were in the billions. Then every major phylum and class appears relativly sudden. That is why they call it an explostion, does the expression adaptive radiation ring any bells?

Ys it was a burst or morphogenesis, yes, Yes 70ma is a brief amount of geological time, but why is it to short to evolve arthropods from base bilaterata?

Especially when there is no way for them to actually adapt on that level, no matter how much time.

This is simply not true, There is a
-70 ma window of opertunity to evolve from bilaterates to the Cambrian fauna. The Burgess shale has proved that the Cambrian explosion is mainly to do with preservation rather than sudden appearence., although this is still an area of research and contention in the palaeontological community.

So as long as you have enough time anything is explainable. Wait just a minute, we are still trying to talk about how the genetic code, with sufficient specificity made this happen. Of course you don't want to talk about how, you have allready assumed that it did happen.

Why you would compare sponges to arthropods is a mystery to me, sponges are not ancestral to arthropods. They are just a simple animal, They were simple in the precambrian, they are simple today.

So What?

These retorts are so brilliant that I feel dwarfed by them.

For which you obviously have no proof beyond your own desire for it to be true.

That and the sneaking suspicion that you secretly agree with it.

Specific lines of DNA code are not written to solve certain problems. Changes in DNA happen through mutation and natural selection.

Newflash! There is no selection process the changes happen at random. Now if you are expecting 1 or 0 at random and you get 18 then take a wild guess what happens next. You find another explanation or you admit you are wrong.

No one said bacteria became Eukaryotic cells, just thatthey have a common ancestor.

Nevermind that it is impossible, lets pretend that it just happens automatically.

That is because for religious reasons you can't entertain it. Science calls common ancestry a well support theory.

It is a widely assumed theory, that does not make it an accurate historicial narrative.

This is because scientist don't entertain religious reasons to omit evidence like you do.

That is right, they only reject anything that might suggest that God had something to do with it. How could I forget that as the most basic scientific answer for everything?

It doesn't appear to be a reputable scientific organisation to me, it appears to be a rightwing organisation with a political agenda.

So the Smithsonian Institute has been over run by the right wingers, we should all life in fear.

I can tell that because I did read the article and then I scooted off around the rest of their site.

care to expand on what they are and what they are about?

They seem to be pretty cagey about it on their website.




Or alternatively after every major extinction in the whole geological record.

You say adaptive radiation is a myth, the scientific community says it has huge anounts of fossil evidence proving adaptive radiation, inluding that of the birds an mammals after the KT extinction.

Oh, who to believe, Mark or the whole scientific community, that's a toughie.




All it's examples are comparing modern evolutionary examples, because they can do nothing else. But nowhere to they adress important points like the evolution of HOX genes and the evolution of regulatory genetics.

Those along with adaptive radiation are more than enough to explain the change from simple bilaterates to the Cambrian fauna in 70 ma.

You have no proof otherwise, and if that paper was your best shot then you failed.

It doesn't matter whether you believe in long fuse Cambrian explosion or short fuse, the palaeontological evidence shows it happened, and the palaeontological evidence will increase of the coming years and bring new supporting evidence as people start to look at the large late Pre-Cambrian deposits of Siberia and China.

That was more of the same baseless nonesense, read the article and consider the evidence. I did want to addrress your bottom line.

But sadly your views will never change becaus ethey are based on your religious dogma not on any scientific basis.

Sadly, you have no idea what my religious convictions are based on. There is a window into history that you are blind to and I think you must be very confused as a result. Good luck with that.

 

[mark kennedy]

By the way, who voted biology and genetics, I would really like to know why if you wouldn't mind elaborating.

 

[Mystman]

No, but this is a peer reviewed article abstract:

Good job with the whole link there.

Anyway, it took me about 10 seconds to come up with something that could potentially give the situation where a single mutation opens up the floodgates for more mutations, and I've only had a few university classes in genetics.

I'm sure that people who've studied the subject for their entire lives can come up with more. (and even do the calculations to prove that their scenario works)

 

[Baggins]

It seems so brief because the years before it were in the billions. Then every major phylum and class appears relativly sudden. That is why they call it an explostion, does the expression adaptive radiation ring any bells?

Yes, it was something you said you didn't believe in.

Especially when there is no way for them to actually adapt on that level, no matter how much time.

For which statement you give no evidence, beyond a disengenous mining exercise from a creationist web site that points out the sponges are a lot simpler than arthropods.

When would you envisage Hox genes evolving and what effect do you think their evolution would have on body plan?

So as long as you have enough time anything is explainable. Wait just a minute, we are still trying to talk about how the genetic code, with sufficient specificity made this happen. Of course you don't want to talk about how, you have allready assumed that it did happen.

Of course we assume it did happen, the evidence is there that it did in the fossil record. At the moment the record is patchy in this period, and the fossils that are being looked for are small and not readily fossilisable. But they will turn up, they always do, to the chagrin of creationists like yourself, once people look closely enough

These retorts are so brilliant that I feel dwarfed by them.

And I, and I hope everyone else will, notice that you made no attempt to answer the point.

Why compare sponges to arthropods? I am assuming that it was to make their case look as strong as possible, but in a rather underhand way as sponges are not ancestral to arthropods.

That and the sneaking suspicion that you secretly agree with it.

Agree with what? That the fact that the fossil record in the Pre-Cambrian leads to the conclusion that life was designed?

Sorry not me.

Newflash! There is no selection process the changes happen at random. Now if you are expecting 1 or 0 at random and you get 18 then take a wild guess what happens next. You find another explanation or you admit you are wrong.

News Flash, natural selection is not random. You know that Mark. And just imagine the selction pressure on flatworms on the like at the end of the Pre-Cambrian ice age, all those new niches with nothing residing in them, a new multicellular bilateral body plan and tens of millions of years to work in. Result adaptive radiation and a proliferation of new body plans.

Nevermind that it is impossible, lets pretend that it just happens automatically.

Says you, meanwhile on Planet Normal the scientific community believes that common ancestory isn't only possible but that huge amounts of evidence support it.

Who to believe, Mark or the whole scientific community, Mark or the whole scientific community?

Again, it's a toughie, but I think I'll side with the scientific community on this one.

It is a widely assumed theory, that does not make it an accurate historicial narrative.

No it is an evidentially supported theory, that you are unable to admit that for religious reasons doesn't change the fact.

It doesn't need to be an accurate historical narrative, it needs to be a well evidenced scientific theory, and it is.

That is right, they only reject anything that might suggest that God had something to do with it. How could I forget that as the most basic scientific answer for everything?

And rightly so, you can't test for god scientifically, therefore it lies outside of science and has no place in it.

When you show us how we can test whether god was involved in evolution scientifically, then god can be admitted to the explanation.

Meanwhile all you are doing is parading a god of the gaps, to widespread ridicule from atheists and dismay from TEs.

So the Smithsonian Institute has been over run by the right wingers, we should all life in fear.

The link isn't to the Smithsonian, it is to the Discovery Institute, and that does seem to have a healthy crop of rightwingers onboard and a political agenda.

That was more of the same baseless nonesense, read the article and consider the evidence. I did want to addrress your bottom line

So you will not even attempt to answer points as I have pointed out the utter worthlessness of yours?

Sadly, you have no idea what my religious convictions are based on. There is a window into history that you are blind to and I think you must be very confused as a result. Good luck with that.

Rhetoric, rhetoric, rhetoric, and an answer came there none.

You don't wish to engage in scientific debate because you don't know what your talking about.

You posted one link to a rather disingenuous essay on a creationist web site ad you think that that is good enough. Well it isn't.

I have posted the flaws in their argument, and you have ignored that.

This whole post is one big handwaving exercise with not a scintilla of evidence, and I think everyone will be able to see that.

I hope others will read the essay on the Discovery Institute site just so they can see what a sorry effort it is.

But in the meanwhile, as you don't actually wish to talk about the science, I will bid you adieu

 

[sfs]

Your sick of it because you don't have an answer. Let me break it down to you again since you don't like to think this through. For 310 million years a gene 118 nucleotides long has 2 substitutions, then suddenly there are 18. What would be expected is 1 or 0 so the HAR is a big issue and human specific sequences is a real problem for the assumption of a common ancestor. No demonstrated mechanism, no proof.

Uh, Mark, you do realize that this kind of accelerated evolution was precisely what this study was looking for, don't you? And that the authors were looking for it because that's what we expect to find as the result of positive selection for a new trait? Where a new trait might be, for example, a larger brain?

The 0 or 1 substitutions is the number expected if selection were still favoring the old trait; that selection was what kept the region conserved. If the situation of the organism changed (because of a new environment, say, or because of a new lifestyle) and a different trait was favored, then there would be a rapid burst of change at the locus while the new trait is selected. There was always enough mutation going on to produce change in this region -- as I wrote previously, every site in the region has mutated at least several hundred times in the last 6 million years. The mutations were only kept at bay by selection against change. When the selection switches to being for change, then rapid change is the result.

You can see the same thing happening in cases where we understand the selective pressures better. Genes that affect skin pigmentation in humans (e.g. MC1R) have very little genetic variation among sub-Saharan Africans, because of the need to preserve dark skin as protection against the sun: most change is eliminated by selection, since change would be bad. In non-African populations, on the other hand, you can find lots of variation in the same genes -- a real burst of rapid evolution, in fact -- because in the northern latitudes, selection favored a different trait, namely lighter skin.

 

[USincognito]

I don't care about ERVs because, frankly, they don't do anything.

Except serve as evidence for common ancestry for chimps and humans.

You can handwave and tell everyone how your incredulity won't allow you to accept brain growth, but the evidence is right there in the skulls of Austral and Homo fossils as well as the genes which you reject "just because."

That's great, but it doesn't mean you can start a thread about common ancestry and just ignore or handwave away all the other evidence that is out there including ERVs, pseudogenes and Chromosome 2.

 

[mark kennedy]

Uh, Mark, you do realize that this kind of accelerated evolution was precisely what this study was looking for, don't you? And that the authors were looking for it because that's what we expect to find as the result of positive selection for a new trait? Where a new trait might be, for example, a larger brain?

The Human Accelerated Regions (HAR) was a look at sections that drop from the mean average (95%) sequence identity to around 89%. What impressed these researchers was that this gene was highly conserved with 2 substitutions in 310 million years (chimp/chick comparison). Then as compared to humans it's 18 substitutions in a gene 118 nucletides long that is expressed in a critical period of brain development. Obviously, had some ape developed an improved fittness as a result of a change in the gene it would be preserved, you'll get no argument from me there. Where you are making the giant leap in logic is that you are assuming that it somehow managed to change, provide an advantage and then be fixed in all successive generations.

I choose to assume no such thing. You guys make such a big deal about the odds of ERVs being in the same place. Then when a highly conserved gene gets 18 substitutions it doesn't even give you a reason for pause.

The 0 or 1 substitutions is the number expected if selection were still favoring the old trait; that selection was what kept the region conserved. If the situation of the organism changed (because of a new environment, say, or because of a new lifestyle) and a different trait was favored, then there would be a rapid burst of change at the locus while the new trait is selected. There was always enough mutation going on to produce change in this region -- as I wrote previously, every site in the region has mutated at least several hundred times in the last 6 million years. The mutations were only kept at bay by selection against change. When the selection switches to being for change, then rapid change is the result.

The key to the whole explanation here is, 'if selection'. If selection was favoring the the 'old trait' or 'if the organism changed'. I understand the simple propositional logic, if beneficial changes could occur then they would be preserved. This begs the question of whether or not changing 18 nucleotides in this gene is even possible. When it says 'by chance' they mean spontaneous, random transcript errors. They only alternative is some mechanism for overhauling this gene along with hundreds if not thousands of others. These mutations you want me to accept unconditionally are like russian roulette, you might get by with one, two, three but sooner or later BANG.

You can see the same thing happening in cases where we understand the selective pressures better. Genes that affect skin pigmentation in humans (e.g. MC1R) have very little genetic variation among sub-Saharan Africans, because of the need to preserve dark skin as protection against the sun: most change is eliminated by selection, since change would be bad. In non-African populations, on the other hand, you can find lots of variation in the same genes -- a real burst of rapid evolution, in fact -- because in the northern latitudes, selection favored a different trait, namely lighter skin.

I can readily accept transposable elements in genes involved in skin pigmentation. I checked into it and the genes involved are different in people with different color hair/skin etc. I can understand how environment produces adaptive changes, recently I was reading about an artic fish that had a brand new gene so I know it happens. I understand the selective process you are describing here but the one that would have happened for us to have evolved from apes would have had to be catagorically different.

We are talking about a massive overhaul of nervous system genes in an extraodinarily brief period of natural history. They are still tracking down the HAR regions, this one was the first of ~49. I still haven't gotten a chance to order the paper and I am trying to get settled into my new home in the sandbox. What I have noticed as these scientists unveil their findings is the shock and awe they express in what they have found. Dispite that, you act as if it is no big deal, no one was supprised in the slightest and there is no problem here. There is one major problem Steve, I read what you guys write and it's telling a different story.

Grace and peace,
Mark

 

[mark kennedy]

I just notice the poll question and the poll answer most people choose. For 'what scientific evidence demonstrates man's ape ancestory'. For the third choice I meant to make it 'muliple disciplines but accidentally wrote 'disciples'. Someone pointed this out earlier but it didn't register with me until just now.

It wasn't multiple disciplines they choose, it was multiple disciples. I don't know if that has some underlying signifigance but it sure has me wondering what people really find persuasive. Is the voice of the crowd or the power of the actual evidence?

 

[Chalnoth]

Nobody is suggesting that all 18 substitutions happened at the same time, but rather sequentially. There was more than enough time for 18 separate beneficial mutations in the same gene to have occurred a number of times over in the 5 million years or so since our split from chimpanzees.

Just for a little thought experiment, consider this: take the human mutation rate to be 175 per generation, and, just for the sake of argument, assume that all of those mutations are substitution mutations (this will clearly overestimate the number of mutations, but we can correct for this later). Let's imagine that we have a total world population of hominid ancestors of 100,000, and 3 billion nucleotides in our genome, and 3 possible substitution mutations (since there are four base pairs).

Now, if we assume that we have positive selective pressure for just one specific mutation in this gene, we will need 50 million births to get that one, specific mutation we want, or 500 generations with a population of 100,000. If we take each generation as 20 years, then it will take approximately 10,000 years for that one, specific mutation to be found. Since we've overestimate the rates a little bit, let's go ahead and multiply this by a factor of 10, to allow 100,000 years to find that one, specific mutation. This should be more than enough time for each mutation to occur and spread throughout the population. So the mean time to generate these 18 base pair substitutions, in a totally serial fashion, might be estimated to have an upper limit of somewhere around 1.8 million years, well within the 5 million year time from when we separated from the other apes.

The only thing that is necesary to explain the number of substitutions in 5 million years is the right selective pressure. What changed in our ancestors to allow the selective pressure that led to the rapid change in this particular gene? Well, we may never know for sure, unfortunately. But who knows? Science may some day find the answer.

By the way, if you find something wrong in my math, please correct me. But I personally feel that the generous multiplication by a factor of 10 of the time expected should be enough to cover any minor mistakes.

 

[USincognito]

For the third choice I meant to make it 'muliple disciplines but accidentally wrote 'disciples'. Someone pointed this out earlier but it didn't register with me until just now.

It wasn't multiple disciplines they choose, it was multiple disciples. I don't know if that has some underlying signifigance but it sure has me wondering what people really find persuasive. Is the voice of the crowd or the power of the actual evidence?

I'm thinking they understood you'd merely made a typo, assuming they noticed it at all (I didn't when I made my choice).

"Forma debate" anyone?